Networking For Cloud Computing | AWS Networking Training | What Is CIDR | Subnetting | VLSM

welcome everyone this is michael gibbs i hope you can all hear me if somebody could just let me know that you hear me by maybe typing cloud architect or i can hear you in the chat box so i know that you're there hopefully you can sit you can hear me and today we are going to have a lot of fun and we're going to be focusing on some networking fundamentals but you know it's me and you know i've been working in networking since 1912 anyway well over 25 years and because i love networking even if we start talking about something as fundamental for example as subnetting we're going to talk about it in a way that's going to build your cloud architect career so sure we'll talk about subnetting sure we'll talk about supernetting sure we'll talk about route aggregation we'll talk about how you can actually plan your system so we're gonna have fun and it's gonna be highly interactive and it's not just gonna be basic subnetting our goal is to build you guys extraordinarily good cloud computing careers so thrilled that you guys are here i see some people that i know like christian and ron and shapur and uh adele wonderful and ran wonderful so happy to have you here and jay and femi and alonso theo and alex welcome for those of you that are not one of our students welcome to we're still so thrilled and super excited to hear you so let me give you guys all a bit of a flow ideas you know what we're going to talk about today but before we begin you really need to know the background of who's teaching the course so it's networking course i'll give you a little bit about my networking background i've been in networking for as long as i can count in fact my ccie number is 7417 now if you know anything about cisco and ccies they were kind of geeky people i was one of them they started counting at 10 28 instead of 0 because it was 2 to the 10th so my 7417 number it basically encompassed all 3 million people prior to me that had worked toward this exam and i was the six thousand forty five hundred guy to basically pass it so that's how long i've been in networking that many years and during these years i've worked for some of the world's largest internet service providers i've worked for cisco i've consulted the internet service providers off the world i set up the voice data and video projects that are spread throughout the world i've designed the systems for cloud providers i've designed the systems for pretty much everybody so i've got about 25 years or which is at least 50 000 hours of experience in networking and well over 10 000 hours and just bgp on another 10 000 dollars in pounds so i've been in the networking world forever these days i i teach cloud computing me and many of the networking people that i've worked with over the last two decades all moved to the cloud why don't we move to the cloud because the cloud's just the next evolution of the network and the data center so i welcome you all to the cloud it is a wonderful place it is the future and there's lots of career opportunity here so in order to be an architect which is what we teach you've got to have the architecture skills what are architecture skills design skills communication skills and what is the cloud it's no more than just a virtual network and a data center so why are we so focused on it because we want you to be great so we're going to teach you the network and today the most fundamental component of the network is the ip addressing scheme your ip addressing scheme will change everything and we're going to do some fun idea addressing schemes today and we're going to bring it into there we're going to subnet we're going to super net our route aggregate we're going to create a routing environment with summarized routes we're going to have a big big big ip party for the next four hours so welcome you're all excited to be here type cloud architect in the chat box and if you're happy to be here please leave a like or a comment it signals the algorithm that we're doing good things so let's begin let's walk through the exact format of the day we're going to begin with what is subnetting after subnetting we're going to talk about what our classful ip addresses then we're going to talk about what goes into subnetting and then we're going to submit and this is going to get fun nick thrilled to have happy to be here arun's super happy and god so thrilled you're here so then when we teach you how to subnet we're going to go in the opposite direction subletting goes one way but they're supernetting which goes the other way and when you're dealing with cider you have to do both so we're going to have fun we're going to go down and we're going to go up and after we do that we're going to do lots of examples lots of examples because we're building cloud architects here and then we'll talk about planning your subnets and optimizing your subnets and then after we talk about planning and optimizing your subnets we're going to do some cool designs and i'm i'm willing to stick around and whiteboard some scenarios and answer lots of questions not super time constrained today i've allocated four hours if you guys are having so much fun you want a little more you got it all we want to do is make sure you have a wonderful cloud architect training experience so you can have the best cloud architect career so first and foremost what is submitting i'm gonna make it real simple all subnetting is is you take an ip network and you break it into something smaller that's it and we're going to show you what that actually means and we're going to show you why but basically you're going to take one rep network and break it into smaller little networks that's it now why why do we have to do this to conserve ip addresses and i'm going to walk you through an example in a minute but we have no issue we have to have to conserve ip addresses because there's not enough of them now i want you to think like a network engineer for five minutes let's say you've got a router with 15 different interfaces one goes to one direction one goes to another direction one goes to another direction each interface needs to be on a separate network so if we didn't summon it we'd have a massive problem i'm going to show you what that would be in a second so without submitting basically we would have run out of ip addresses so many so many years ago so let me walk you through an example and this is not the official symbol for a router this is this is someone on my team that's a graphic artist that i ask him to basically make things light and fun so we can all learn look at these addresses that are used here if we were using a classful network without subnetting we're going to talk about what that means let's say we have the 2.0.08 and the one dot one dot zero to one that zero zero zero slash eight and the three dot zero slash eight and the four dot zero zero slash eight what's going on here well each interface needs to be on a separate subnet and if we used these four networks just for four interfaces on this router we'd be using 64 million ip addresses and i'll show you why but this would be 64 million ip addresses that are literally wasted on one router and nothing else in the world why because there's a slash eight and i'm going to show you the math we're going to back into the number of hosts number of networks we're going to get there understand that if we didn't do subnetting here we'd basically you'd be wasting 16 million ip addresses per port now let's go break into something where i did some subnetting here for example i broke those network downs into something that matters guess what how many addresses i'm using now four for the top four for the left or the right four on the bottom and four to the left so realistically speaking or just by looking at that i've saved 64 million addresses minus 16. that's why organizations submit to use their ip addresses properly using 30 or 16 versus 64 million that's the reason so now when we before we even get into this we've got to get into the concept of classful addresses especially when we start talking about ipclassful cider subnetting super netting now you're getting into some really complicated stuff so we're going to walk through some of these things from different angles and i'm going to show you what they look like and then we're going to have fun with it so let's go to this particular situation here originally speaking when the ietf came up with the concept of ip addressing and people were using this many many many years ago there weren't that many people on the network in fact when the internet came around it was a couple of universities and darpa and it was an experimental universally such military research project you know there were a couple of remote locations and they looked at it and said this is great and no one expected the internet to do what it did no one expected it to blow up no one expected you know everybody to have a iphone or or a samsung phone or whatever have three phones in a house that all need their own unique ip addresses a compute multiple computers in the house um web servers everywhere apple servers everywhere internet of things devices rfid tag nobody planned on this what did we all think was going to happen but 10 devices on the networks nobody thought about it so the ipv4 address is a 32-bit address which is a whole lot of addresses just not enough for today's world now initially speaking they came up with the dress classes there was a class a a class b a class c a class d and there was this experimental class which nobody's ever done anything with so what is class a addresses these are the slash eights that you see now most specifically a class a address begins with a one like 1.0.0.0 or 1.0.1 and goes all the way to 126.255.255. that's the limit that's the broadcast address for that subnet so these are big big big these class a addresses lots of addresses you want to how many addresses you have on one of these subnets you're gonna go 2 to the 24th power minus 2. we're going to show you in the next slide when we get into some subnet stuff we're going to have lots of fun with this stuff when we get into this subnet stuff we're going to be calculating the actual addresses that are there so you'll see that there's basically speaking 16 million addresses with the class a now as i previously showed you if you actually applied a class a to anything it would use up all 16 million addresses so you've got to submit this down if you want to do something i also showed you how i could use 64 million addresses without subnetting versus 16 addresses with subnetting wow 16 million 16. like a million times more that's how efficient something can get you and that's why we have to do this now the next concept of the class b which is a slash 16 began with 128 and went to 191. so the private ip address space like the 172 16.0.0 class b address plus b private address but a class b address now it's got a 16-bit subnet mask so in a minute we're going to talk about the host mask the subnet mask bits and bytes and all of that but class a zero basically one to 126 class b 128 to 199 class c addresses which by nature 24 which give you 253 addresses well technically 254 but that's either um and that's 192 to 223. now when we start getting into class d addresses this is for ip multicast um there's no subnet masks that we're going to be dealing with and classy or experimental drugs and they're not there so now let's look at this from another angle a class a network has eight network bits and eight host bests hmm what do i mean by that eight network picks and eight host bests so we'll work through this in a second now the class b has 16 network bits and 16 host bits while a class c has 24 network bets and host bits so let's let's draw this out a little bit for you we'll do some interactivity while we're having fun here so for example let's say we we have an ip address that's network best the slash 8. so what the address is going to look like is network and then here's the host bits it's going to be a dot you're going to 1 1 1 1 1. let's say we can be ones or zeros so we're just going to take ones one two three four five six seven eight one two three four five six seven eight one two three four five six seven eight so that's what a class a looks like these these ones are zeros or host bits the network piece is the network so let's look at how we could calculate how many come here and we're going to get through this i'm going to do it a lot of ways but one host bit so a slash one host bit means one host two host bits is something different four host bits is something different so this is binary when you're dealing with an ip address and you're realistically speaking let's just make this all ones for right now you're dealing with a 32-bit address so the total number of ip addresses in circulation is going to be 2 to the 32nd minus 2. so someone in this audience tell me tell me how many ipv4 addresses actually exist well we're going to potentially exist if we didn't have the class d's or multi-class and the class ease which we don't use 2 to the 32nd minus 2. that's what you're going to need to know so we can work it out together to sum this so for example 2 to the first equals two or two to the second equals four two to the third equals eight two to the fourth equals sixteen two to the fifth equals thirty-two two to the 6th equals 64. 2 to the 7th equals 128. so that's basically how you're calculating these things to determine things so our room 65536 is unfortunately not the total that's the number of addresses available for class b two to the sixteenth minus two will get you to the to uh to uh six five five three six you're dealing with two to the second thirty second power minus two so you can take a scientific calculator and do 2 x 32 that will give you an answer minus 2 and then you'll see exactly how many how many how many hosts you're going to get there net cloud 4.2 billion that sounds about right so there's 4.2 billion ipv4 addresses now let's think about that seven billion people in the world could almost make it especially with private ipa addresses no big deal what about these iphone what about people's mobile phones they need an ip address seven billion people in the world how many mobile phones probably seven billion okay so poof that's a problem how many servers in the world billions okay that's a problem how many people have a computer in their house which means an internet connection which means a public address okay that's a problem so now you see why we have to submit these things down we need to use these addresses more efficiently so with a slash eight you've got 16 million usable addresses but every time you put an address on an interface it's all used up and you could what if you said what if we plug them all in the same vlan on a switch 65 000 hosts to the vlan would it work from an ip addressing perspective absolutely sure no problem we want to work in a reality perspective because once you get above say 250 to 300 hosts the hosts do broadcast they say hey you there are arp who has this mac address i'm a printer i'm here do you know it netbios net movie these systems they send broadcast constantly and what happens is they fill up the links you've got to constrain them the only way you constrain them is with subnetting and by placing them on additional interfaces so that's why we do these things and that's why we focus so hard on breaking them down class a eight network bits and this so what does a class a look like it looks like something as follows two five five because that's the only number of network bets we have dot zero dot zero dot zero that's a class a subnet mask now a class b has 16 bits of nut of subnet mask so it's going to look like that and a class c has 24 bits of subnet mask okay so how do you count the subnet bits well the way you're going to do it is as follows and this we're going to build this thing and we're we're going to walk through lots of times and lots of examples so i don't expect it to be necessarily instant but we'll get there so if you were to draw a link of dot 128.64.32.16.8.4.2 dot one automatically we have one two three four five six seven eight okay so that's basically what's going on when you look at your subnet bits for example this is a slash 32 this is a slash 31 which isn't usable this is a slash 30. this is a slash 29 this is a slash 28. this is a 27. i might be doing some wrong funny mouth here this is a slash 32 this is a slash 31 this is a slash 30 slash 29 28 27 26 and 25 so understand we're going to be playing with subnetting by literally speaking playing or manipulating with the actual subnet bits so for example this is over here realistically speaking with a slash 24 the last octet of host bits this is what we've got so you know what we're going to do i think we're going to it's going to come to a better information when we work through some examples together so i'm going to keep moving on and not stop here but remember class a eight network bits class b 16 network that's in class c 24 network bits okay so now we're going to do some subnetting which is just borrowing bits okay everybody tell me right now two to the 16 minus two how many ip addresses did that have a room was darn close two exponents 16 minus two chanting sure let's do this so if we're dealing with a subnet and in this subnet what we're dealing with is apparently this is a this is a slash eight so this current subnet right now for example 65534 is correct so right now here is the class a this is what a class a subnet mask looks like that's what it's going to be for the class a address so what would a class a address look like it would look like as follows it would look like 1.1.1.1 that would be a class a address now that address itself being unsubnetted can go from 1.0 just showing you the range could go from 1.0.0.0 all the way to 1.255 for a subnet directed broadcast this 8 16 24 is 24 host bits so 2 to the 24th minus 2 is a couple million ip addresses so that's there's actually 16 million ip addresses that are in the subnet but you can't put 16 million ip addresses in a subnet or in fact you can't even put 500 on the subnet before you run on a broadcast so this would be silly so let's then say let's further reduce the load here on the subnet so instead of having eight bits of subnet mask let's pick for example a subnet mask that we need okay let me ask all you guys example and chime it into the window if i need a router which has one link only one link and there's one person on one side and there's one person on the other side how many ip addresses do i need for a connection that can only have two people okay so my ceo chris is on this call if i want to create a connection to chris how many ipa addresses do i need from my how many ip neil kumar exactly two i need two iep addresses exactly two ip addresses so how many should i use on a subnet for to connect me to one person if i only need two if it wouldn't be efficient i'd want to use two the reality it's going to be four we'll talk about why it's going to be four but i want to use the least number of addresses possible so if i've got a point-to-point link between point a and point b we're not going to use a slash eight we're not going to use a slash teen and guess what we're not going to use a slash 24 we're only going to need four addresses we only need technically two but we have to use four so what's going on here instead of using this what we might do what we would do is we'd further break it down we'd say let's take some extra subnet bits because we don't need the host bits so by creating more subnet bits we can create more networks now what i might do is say wow we need a one dot one let's say we might have a 1.0.0 let me make sure i can type.0.0.0 slash 30 this this could be an ip address that would use for example slash 30. why would we do this what does slash 30 give us what is a slash 30 going back to our binary bits to so let's see of the last octet so one two three four five six seven eight that's our last octet slash thirty gets rid of a few of these bits this is a slash thirty two this is a slash thirty one this is a slash 30. so the slash 30 would do the following it would turn these subnet bits to a zero and we'll walk through the calculations so it turns it to a zero and by turning it to a zero a room we study networking this is not aws this is not gcp regardless of either one of these things when you're doing a direct connection or roon you're using slash 30s it's different between what you do in the vpc and how you connect to a vpc that's what we have to focus on the network not what a cloud provider does because we're designing networking things here love the motivation i love that you love gcp um but we're taking a step back on aws and gcp you still do this kind of stuff on a direct connection it's a slash 30. so let's get there and i also saw a rooney asked a question what happened to 127 okay what happened to 127 go to a command prompt on your computer and ping 127.0.0.1 do it on any system in the entire world ping it's ping 127.0.0.1 what is the 127 dedicated for it is dedicated towards the internal loopback address of all systems so that's why 127 doesn't get used that whole subnet is designed for you to basically test your own system and see if it exists there's a fantastic question there around but going back to the actual networking once we get out of the cloud providers because you've got to deal with real networking not cloud networking when you're connecting to the cloud you've got to get these subnets correct so those subnets are as follows so this is what a this is what a class a that's been submitted down to a class c is going to look like one two three four five six seven eight one two three four five six seven eight this is the binary subnet mask one two three four five six seven eight now when you see this can anybody do the math and tell me what this looks like i'm going to show you how to do the math but realize this is 255 in binary this is 255 in binary this is 255 in binary and this is 2 5 2. so this by the way is going to be your subnet so when we deal with a subnet like this this is the beginning of the subnet or the network address we're going to always have a network then we're going to have host address 1.0.0.1 which is which is going to be a host address then we got to get rid of that 2 to the third is 8 exactly but it's 2 to the second you're going to do a road you're not going to use a uh a 2 to the third or a slash uh 28 for a wand link you're going to for for a win like you're going to always use or sub 29 you're always going to use a slash 30. and naga the reality is is ipv6 is not used by much at all right now it's only used on mobile phones maybe 10 years from now we'll be switching over to ipv6 i remember when i first trained on ipv6 15 years ago it was all going to happen tomorrow it's not here it's very far away and yes we're starting to do things but ipv6 is predominantly just for mobile phones it may take us another decade to get to ipv6 naga that's how far away all the network providers all the host providers are on the entire networking industry so yes that matters um but we're doing ipv4 because 99 of the world's networking outside of mobile phones is all on ipv4 and i know tremendous numbers of ccies that have never even worked with ipv6 that's how infrequent it actually is so i'm familiar with it i've used it but most have not that's how little it actually is and so it's not going to be replacing anything anytime soon except for ip mobile phones but it will be getting there at some point in the future um but you know five years from now 10 years from now when that becomes more prevalent we'll be teaching that as a current skill but right now it's a future skill a skill that's predominantly reserved for the ccies like me that are working on mobile phone networks like 5g networks each one of those things has a mobile phone but not for normal people and definitely not for most cloud architects under normal circumstances unless they're cloud networking people like me that are also ccie so that's what we're really focusing on the things that most people need to know so we're gonna have to build these uh subnets together so you all get it but really something what's happening is we're taking this and we're breaking it down we're just chopping it up so that's realistically speaking all that's going there so now how do you plan your network and we're going to go through hundreds and hundreds of of examples today because you guys are going to know there's not going to be anybody that doesn't know but let's just walk through a little bit more first so what are your constraints what are you thinking about here as a cloud architect i can tell you what you're thinking about right now you're thinking about how many subnets do i need how many hosts do i need um if i need 250 hosts i need a subnet that can support 250 hosts if i need four meaning two real like on a wan connection i'm going to use the slash 30. what if i need 500 in a subnet which is the maximum pragmatic limit i can't use the slash 24 because that only gives me two what do you call it 255 addresses but poop i can go to the slash 23 which will give us 512. so i'll get to that and it looks like aaron to the question okay arun your ip subnet for the example you gave me is 1.0.0.0 the address used for the gateway in your data center is 1.0.0.1 the address used for the gateway in the cloud would be 1.0.0.2 and dot 3 is a broadcast which would not be used so whether that's a router at the cloud on the end whether that's the router or the branch office outside of networking it's always going to be a slash 30. whether it's gcp whether it's azure or whether it's mike's home network it's always going to be that way it doesn't matter that's the way you create a web design link it's a point-to-point slash 30. now in these cloud providers they have their own ridiculous reasons like aws inside of their organization reserves the first four and the last ones you got to do this google does something goofy too that breaks normal networking world so does microsoft but in networking we use slash 32s and for wind links we network 32s for loopback addresses we use 30 for web links and that's what we're teaching you today so when you're planning this out what you're really doing just literally speaking is planning your subnets based upon the addresses that you actually need so let's look a little more about some of these things and we're still going to start getting into the fun when you're looking at masks remember i told you the 2 to the x minus 2. that's the formula because you're dealing with host bits two to a slash 30 because you borrowed two host bits gives you four total hosts subtract two because you and now you're down to two why am i subtracting two because you've got the subnet and you've got the broadcast we're going to walk through lots of examples you borrow eight host bits which is a two five five two five five two five five dot zero basically a class c if you do two to the eighth guess what you get 256 but you got to subtract two for the network and the broadcast so that's how you go you want to use instead of you want to use a slash 23 instead of a slash 24 you've got 512 addresses you want to use the slash 282 instead of a slash 23 it goes up 20 48. you want to use a slash 12 it goes to 496. i mean a i'm sorry a slash 20. you want to use a slash 19 instead of a slash 20 it's going to go to 81.92 and so on and so forth because it's really going to just be based upon these bits and bytes so let's let's break it down into more graphics this class b address we've got 16 bits of subnet mask or 16 bits of subnet mask now over here we've got we could do some additional subnetting if we chose to to break it so normally it would be a slash 16 so 16 bits of subnet mask can anybody tell me what is 2 to the 16th i think arun did it pretty quickly before fail q did something infill 2 to the 16th minus 2 how many ip addresses are in this class b network two to the sixteenth minus two okay i'll get a you guys are getting sleepy with the math up pull out a scientific calculator 65536 sounds about right so perfect that's the slash 16. so arun since you did the math let's say we wanted to borrow an additional hope host bit and william wallace is technically right six five five through four our room forgot to do to subtract the two but perfect um so let's say instead of a slash 16 let's say we want to do a slash 17 we're going to lose one subnet bit and we're going to give an extra one to the hosts so so what would that look like if we go from 2 to the 16th minus 2 to a 17 which is going to be a 2 to the 15th minus 2. how many ip addresses are we going to have then 2 to the 15th minus 2. i know there's this hard delay um so if we go from a slash 16 which you guys have all astutely done six five five three four and then we go to a slash 17 meaning we borrow one extra bit here so here's what a slash 17 is going to look like um no slash 17 versus slash 16. so if a slash 16 is 2 to the 16th minus 2 uh slot william wallace excellent minus i think you sub you may have to subtract 2. so it's going to be 2 to the 15th minus 2. that's how many addresses you're going to get for a 17. how about a slash 18 2 to the 14th minus 2. they have a great job so let's really now let's let's do this let's show you what these subnet masks actually look like in binary and decimal 255.255. so this is what we're getting out of the class b roon i'm not sure which one you're doing so we had done the slash 17 which gets you to the 32766 and then we're going to do the slash 18 which william wallace did a great job 16 3 8 0. now let's say we're going to do a slash 19 instead instead of a slash 18. we're moving over we're going to basically have more networks and less hosts per network so if two it so what does this look here's what a slash 16 so we had a slash 16. let's see we had a slot we have so we had over here so first we had a 16 16 then we had a slash 17 which looked like this then we had a slash 18 which looked like this then we had a slash 19 which looked like this now let's have a slash 20 which looks like this how many how how many hosts are we going to have available with the slash 20 which looks like this 255 255 240.00 arun great job it's somewhere around 8190 that's exactly right arun good job arun good job at dell now instead of the slash 20. let's make it a slash 21. what's the slash 21 going to look like 1.1 so obviously the first two octets are all ones because that's a week 255 and i'll show you how to do the math yeah that's a good typo there william um i i you're usually doing a great job but i've made much worse typos i'm with you um so okay so now we have a slash 21 great job 2 to the 13th minus 2. good job you guys have figured it out it's four zero nine four okay great now let's add another one let's take ourselves to uh two five two how many we have with two five two two to the tenth minus two good job there gz so now let's do this let's go make it a slash 23. two to the ninth minus two how many do we have actually some people have made some math numbers that are a little goofy over there um because actually um the slash 20 2 should give you basically uh 1028 addresses so somewhere on there juicy i'm not sure whether or maybe with the delay going back and forth because there's like a one minute delay so anyway um 510 for two to the 23rd brandon bowman exactly two to the 22nd gave you a thousand and twenty two excellent guys you guys get it you guys are getting the knowledge so slash 23 is basically 510. slash 22 is basically 1022. you guys are getting it you guys are doing a great job let me go reset this to what it is for the next time somebody asks me to do this and you guys are getting we're going to be doing a lot more problems and then we're going to subnet up we're going to subnet down we're going to design ip addressing schemes it's gonna be fun for network so if you guys are enjoying the network training type cloud architect so i know you guys are here so now let's walk through some of these subnet masks i'm not really sure what you have with the number two there but that's okay we'll have lots of chances to get through a lot more thank you guys for letting me know if you're paying attention with cloud architect if you can leave a like it helps us with the youtube algorithm and we really appreciate it if you can tell others about the free training we do to help the cloud architect community again that's something we truly appreciate so two to the eighth for a slash 24 exactly a roon is 254 addresses there's also another cheat way we can show you but we want to show you the correct way first so you guys are doing great here now you guys are picking it up so you guys are letting me know you're here by using the word cloud architect which makes me thrilled i'm going to go to the next content which you guys will hear in about 30 seconds from now note what we've done here what i've done in this example is i've taken networking subnets that are and converted them into binary because typically speaking you hear cider notation slash 30 then you see traditional notation which is 255 255 255.252 and then you see binary rotation which is a bunch of ones and zeros so um when i see all this stuff i want to make it clear let's go to the top of this over here right in this section over here this is what a slash 32 really means that's actually not the cheap way or what i'll show you the cheap way um it's a very very cheap way well i'm actually the one that'll work almost every time for a slash 24 unless so in this example we have cider notation what is cider classless inner domain routing we're going to cover that plenty don't worry what is classless inner domain routing quite frankly it's just this remember i told you about these ridiculous class a class b and class c addresses where class a's would basically give you 16 million addresses and class b's would give you basically 65 000 addresses and classes would give you basically 254 well a slash 24 is a 255.255.2550 basically a class c binary terms it's all ones in the first octet all ones in the second octet all ones in the third octa and all zeros in the fourth now this is follows a slash 24 so basically look at it you've got a 128 a 64 a 32 a 16 an eight a four a two and a one and when we start counting subnet bits we count from left to right so we start moving in this direction so what does that equate to if we steal one bit of subnet mask we add a one here so well slash 24 is all ones all ones all ones and then zeros the slash 25 is a subnetted class c we took a bit of host bits and we squished them and stole them and gave it to the network instead so we have more networks so what does 128 look we've got one bit here and then the rest is going to be zeros so add one bit to the 128 and when i ask you guys to calculate the subnet soon you're going to see why this is important we've got a 128 so it's a slash 25. now what does this slash 26 look like slash 26 all ones in the first octet all one's in the second octet oh one's in the third octet but now we've got a 128 bit in the 64 bit can anybody tell me what's 64 plus 128 do the math real quick and pop it in the chat box somebody help me with math i'm not good at math i practice medicine i'm a verbal guy i don't like math how many tell me i can do math well 64 plus 128 what does that equal sam you got it 192 bow wonder 192 adele 192. you guys are making me so proud i am so happy i could cry here when i see the cloud architect community getting good at networking i am thrilled you guys are doing fantastic keep up the great work really really thrilled to have you so you guys got it so what does this thing look like now you've seen it in binary notation five so in binary it's all ones all ones and then we stole two bits and in what do you call it we've got insider note in standard notation we've got two five five two five five two five nine two does any of everybody see where we've got the slash 26 and why we've got eight bits over here eight bits over here and apis over here but we also stole these two bits so 8 16 24 plus 2. that's how we get to 26. now everybody we're going to have more phone we're gonna work our way talani i am so happy you got this awesome talani so and that great um just like a class c exactly so classless interim rounding gz basically said we don't believe in classes anymore they're ridiculous so they're all gone all gone that's what classes in our domain routing is so now let's do this let's let's now take three host bits and turn them over to the network so instead of having you know two five five two five five two five five one nine two we're going to have three subnet bits so we're gonna have a 128 a 64 and a 32 somebody tell me what that adds up to mathematically speaking i'm not mr math my wife is you can do calculus in her head i'm not mastermind that's why i have super smart quantitative data scientists on my team because they're great at it so somebody tell me what is 128 plus 64 plus 32 and you've now figured out the slash 27 subnet mask add them all up bow winder excellent arun excellent two two four so what do we have here we have two five five two five five two five five dot two two four or slash twenty seven how do we get to twenty seven eight plus eight plus eight plus three makes sense so now here's the cheat way to figure out how many hosts we're going to have in the subnet how many hosts we take two 226 minus the subnet mask minus 2. so if we took 256 minus 2 224 that will tell you the maximum number of hosts and then you subtract 2 0 in the broadcast and now you get it so now you guys we're backing in we're backing out we're going to summarize and go up we're going to go down we're going to go all up and down on this charts so now let's do a slash 28 which oh by the way is the smallest subnet you could potentially use in the aws cloud would i use the slash 28 no i wouldn't because it's ridiculous especially in aws i'm going to use and as a rule here's the recommendations i have you wait for you when links slash 30. there's only two addresses lan links where your servers are going to be slash 24 why you're always going to need 10 times more servers than you think you need it's just a matter of time and on the cloud you're going to be auto scaling your load balancers are going to be scaling your servers are going to be scaling you got to scale this stuff out if it doesn't scale out and grow your systems don't grow so for the cloud the smallest one that i recommend is a slash 24 and i recommend a slash 24 being generally speaking the smallest address space you ever use in a lan interface slash 30 is typically used on a way interface slash 32 is typically used for a loopback every network architect in the entire world does this okay so jay-z let's um let's let's you've asked a valid question so what's going on where do these things come from so gz what is 2 to the 8th 256 right so 256. so the way this would work exponentially is you would have a 1 a 2 a 4 an 8 a 16 a 32 a 64 and a 128 so because that's the way it exponentially would work and we subnet from left to right meaning we're taking we're borrowing bits from the hosts so how do we get to 256 let's take 128 plus 64 plus 32 plus 16 plus 8 plus 4 plus 2 and plus 1. somebody add that together i'll add a two we'll take two two four oops plus four plus two plus one that's the 255 so for so for example when you cancel my phone so if we do two to the eighth that gets us to 255. so we're just adding them all together exactly greg you got it perfect but we are starting from the left and we are going to the right and why are we going from the left to the right because that's the way something's done you guys are doing fantastic i'm super proud so perfect so now let's walk through this just a little bit more let's go to the slash 29 it's gonna be one all ones for the first octet all ones for the second octet all ones for the third octet and then it's going to be one one one one and one so we've borrowed five of the eight bits so we're going to have a so we're going to be using a 128 plus a 64 plus a 32 plus a 16 and an 8. so somebody add them up for me they can tell me what the subnet mask is going to be come on you guys are doing great 128 plus 64 plus 32 nice good job excellent so 256 minus 248 divided by two how many host addresses that's the cheat way or you can do two to the third minus two you have to actually start with two 56 to get to the 248 to calculate the number of hosts you're going to start with a 256. why do we start with 256 because in the us we start counting at 1 and the remainder of the world we start gaining at 0. so we're dealing with these numbers we start counting at 0 on the way to 255 and that's how we get to 256. so we can do 256 minus the subnet mask which is 248 which will give us eight minus two which is six or we can do two to the third minus two arun you get a cigar you figured it out great job totally pleased totally happy so hope you guys got that now let's go from the slash 29 to the slash 30 most common when link in existence slash 30. what's that going to be oh it's going to be a 128 plus a 64 plus a 32 plus a 16 plus an 8 plus a four what's that going to look like everybody okay sure about winter i'll repeat my cheap way now about wonder for someone like you that's got good math skills i don't recommend using the cheat way but for someone like me and good job arun um that doesn't love math is each one of these octets at full capacity note it says 255 right so let's look at this what's 0 1 2 3 4 5 six seven all the way to two fifty six well only two fifty five it's actually two fifty six so what we're doing about wendra on the cheat way if we wanna figure out how many hosts per subnet is we're taking 256 which is the total maximum number per subnet because we're starting at zero we subtract the subnet mask and then we minus two and that will always give us so if we had a slash 30 for example which is a two five two we could do 256 minus 252 which gives you four subtract out the two we've got two usable addresses or we could do two to the third or two to the second which gives you or yeah wait i'm doing something funny with my let's just go there but that's the way it realistically is speaking it works so now let's do a slash 31 the slash 31 is a subnet you will never ever ever use in life because you can't use it because when you're dealing with the subnet this the first subnet is a zero and the last one is a broadcast so in a slash 31 you've got a total of two addresses meaning this is the broadcast and the subnet so you can't use that but you can use the slash 32. what is a slash 32 a slash 32 is a host address and you might see a host address on a router as a loopback address and it might look like this and it's just that address that you push there um it's a host address and so you can put this on one router and the next router i can put this slash 32 and basically it's a way to truly maximize address space but this is only used as for loopback addresses on router so i would say unless you're a routing and switching person you're never going to use anything smaller than a slash 30. slash 30 is used on a wide area network point-to-point link trying to mute all my notifications bear with me busy executive i typically get about 100 slack messages 100 emails and about 100 text messages per hour plus you know at least a dozen phone calls i have them on mute but that's typically just the story of my life so bear with me so let's play with this now so i want you guys getting it i don't want anybody leaving any of my training without really knowing what they're doing so feel free to ask questions and you got them for the next thing to let me know if you're having fun let me know by typing cloud architect that's how we know that people are there we love the cloud architect community and let me know if you're seeing it watching and having fun with cloud architect and then we're going to enjoy more fun and while i'm waiting for some people to let me let me know that we're getting on the subject projects you just want to know that you're there you guys see me doing a pretty good job arun you're one of my students you don't think in terms of gcp ever you think in terms of designing the solution for the customer because that's the togaf way that's the enterprise architect way it's the cloud architect way if i know i need a compute instance it doesn't matter to me whether i go to google compute engine aws ec2 or azure it's all the same that's just the name of a brand if i go to the store to buy a shirt and i want a cotton t-shirt it doesn't matter if it's nike or roz or adidas it's just a shirt so we got to think in actual terms of what we're designing doesn't matter what google wants doesn't matter what aws wants pick the right subnet what subnet that i tell you guys to use for land links a slash 24. what did i tell you to use for land links a slash 30 it works on every cloud every data center every network everywhere anytime so i don't ever want someone to focus on a single cloud you will never in real life be just on working on a single cloud in today's modern world it's going to be a hybrid cloud it's going to be a multi-cloud it could just be all the data center or it could temporarily be on a single cloud exactly or when it slash 30 migrating to multiple clouds and if we only know one cloud it'll be miserable when i go to greece i stay i think in greek and i speak in greek if i tried to think in english and translate it to greek it wouldn't work focus on the big picture that's what an architect designs from there it's just a matter of picking out the services per cloud guys are doing great so we're going to do some more subnet training but my team has reminded me that i should post a link to our training so i'm going to do so my team has also reminded me that i should post a 20 discount coupon code for anybody that's interested in training my team has reminded me that for anybody that's interested in signing up or asking questions about our training that they can uh what's the word i'm looking for they can call our office so let's get back into some fun training now going back into our super fun training and experience time now let's go uh go back to these slides so i'm going to start with the roon you've been pretty vocal now we're going to pick people out of the group i want you to tell me what is the be actually you know what i'll do the first example and then after that a rune you're going to do the second one so let's take this particular ip address 192.168.1.132 now what does that really look like in terms in terms of let's look at cider notation and actually as chris said you know chris could potentially be asking um the reason i tell my students to use slack is the corporate phone gets used by multiple people per day so if you want to reach me use slack because chris might answer my wife might answer she's also involved in the company somebody else might cancel if you call her primary number but you'll but uh but that's what she was saying but we will definitely call you back anybody that's got a true question for me about our training i will get back to you and any of my students can reach me via slack or they can reach chris who's available to make sure that everybody does well so let's look at this actual address if we look at a slash 25 it's going to look like 255 about 255 dot two five five dot one twenty eight that's what it's going to look like in binary it's gonna be this one two three four one two three four one two three four five six seven eight one two three four five six seven eight one one two three four five i may have actually miscounted but that's what this is going to look like architecturally speaking so i need someone to tell me where the subnet begins and where the subnet ends for example where does this subnet begin slash 25 this is what it looks like does anybody know um so typically speaking the first address of the subnet is usable i'm sorry is restricted for the network the last ip address of the subnet is restricted for the broadcast does anybody know where this 192 168 1.132 subnet begins if not i'm going to walk you through it okay well i see no answers so i'll walk you through it if we look at 192 168 1.132 our roon great job it's 128. does anybody else know how a room got to 128 where the subnet began subnet begins i'll be at 128. okay so when we're dealing with calculating the subnet and calculating the broadcast the subnet is all zeros so what is this what is this plus all zeros it's 128. but if people didn't get this and i think a lot of people probably didn't let's be real answers 132 is the is the address that you guys were given right is 120 if 122 what's it divisible by is it divisible by 128 yes with change right is it divisible by 128 plus 64 no so the sum that's going to begin by what is divisible with 132 is divisible by 128 and it gives you like one points whatever whatever and change so that's your answer but it's not divisible by 120 192 um but it's not divisible by 12 i'm sorry what's the what's the what's the word i'm looking for it's not divisible by 192 with a whole number so you need the whole the largest whole number um what is there by the largest whole number what do i mean by that um 128 so it must be there it must must must be there one second and kisha we're actually going to get your questions uh one of the mbas of my team is going to answer that we want to teach you to think like an architect because you know um it's pretty important i want you to really really understand how to how to do architecture and whether it's planning your career or planning dealing with your customer it's the same process so for example let's just take a break into architecture kesher said the course was too costly if the average architect learns six hundred dollars a day and somebody gets you a job three days sooner than you would have on your own um that's an eighteen hundred dollar value to you even of course was fifteen hundred dollars you made money by taking the course so if a course for example cost you ten thousand dollars but it raises your salary a hundred thousand dollars a year it's the cheapest ten thousand dollars in the world so as in businesses and technology folks i've been we're going to get back to those when you're designing a solution for a customer that's going to cost 200 million dollars and a 200 million architecture is nothing i've sold multiple billion dollar architectures before and i'm peaceful with you as well handle god if the 100 architecture doesn't save your customer any money 100 million dollar architecture is expensive if you sold the customer a 300 million dollar architecture and they sold the save the billion dollars a year it's the best investment they've ever placed so i spent a quarter of a million dollars in education but retired at 34. that quarter of a million dollars was awfully cheap so it's a matter of you know doing roi modeling in everything that you do is education expensive yes good education is expensive is the education going to be more than paid for by building your career then it's worth it if the education does not create a greater value for you then it's not worth it a fifty dollar udemy course that doesn't get you hired is a fifty dollar expense a five thousand dollar course that raises your salary a hundred thousand dollars a year is awfully cheap so look at it that way best way i can describe it i'm saying this because whether it's training or architecture you still have to do that same roi modeling you will must do that for your customer so if you're not learning it from me because it's expensive that's fine get an mba go take our modeling training you've got to do it you have to know how to do this as an architect so i want you to be successful train with us great train with somebody else great but you need these jobs and you don't suck nobody sucks we'll get you there carrie uh if you you're struggling we'll keep going we've got hours and hours and hours more to go and nobody's going to be left behind no one so we'll make sure you all get it you'll definitely get into this you'll get any job you want let's just eat right think right train right and we can accomplish anything so arun you did a good job the 192 is divisible here so arun you told me where the summit began 192 168. or i'm sorry about 1.128 now arun where does the um carry if you've got an issue call our office and we might be able to work with you are you a reef so happy to have you so now arun where does that subnet end since you know where the subnet begin what is all ones meaning if you added a one a one a one a one a one a one and a one what does that look like a room you still there so if 128 begins the subnet where does that subnet end what's left let's add the 64 plus the 32 plus the 16 plus the eight and the four and the two what's that going to give you 126. so happy you're here um so the last usable address nick love is 254. great job theoq the broadcast is 255. the last usable address is 2-4 ran you know i'm sure you meant to say 255. derek255 you guys have got it the broadcast is two five five then the subnet is 128. the broadcast is 255. the usable addresses are 129 all the way through 2024. don't worry if you guys missed this we're going to do a lot more examples okay next one we're going to go left to right so somebody over here that wants to take this challenge a reef you like networking you're first okay 172 a wreath 16.1.27 27. what does the slash 27 subnet mask look like a reef 255 255 plus 128 plus 64 plus 32 that magic number is 224 what does it look like in decimal and binary price places it's going to look like this okay calculating from right to left there there which is one of my favorite things to do calculating i count i read in multiple multiple directions from depending upon where i'm at some places read in one direction some places read another direction it's all good but in subnetting we read left to right just like most american movies left to right american books so left to right so when we start talking about these things or a reef since you like networking which i'm thrilled where is the beginning of this subnet let's take 27 and divide it by 220 224 and let's come up with a actually before we do that is uh 27 divisible 27 divisible by 128 no is it divisible by 64 no is it divisible by 32 no is it divisible by 16 the answer is yes so that should help guide you a reef so arif where is the beginning of this subnet where is the end of the subnet and if i put you in the spot and you just popped in you can just say michael do the next one and i'm totally respect that or the one after that it doesn't matter but where do we begin this subnet it's divisible by 16. so what would a subnet look like 0 to 15 would be the first subnet what would the next subnet be 16 to 32 or 16 to 31. so somebody tell me where this subnet begins the 172 16.1.127 realizing subnet 0 goes to from 0 to 15 subnet 2 goes from 16 to 31 subnet 3 goes from 32 to 47. bellwinder you got it 16 to 31. reef you do great i've seen you in class you're super smart super capable and the things you accomplish are awesome so if i threw you on the spot within three seconds of you saying hi mike i'm here don't worry about it or if you are doing fantastic literally fantastic so all good so balbinder got it perfect somebody else this is going to be a slash a christian this is not going to be a slash two to four to slash 27. oh 27 is a slash 24. uh apologies for that so 128 so we have ones for the first eight ones for the second eight one for the third eighth and then we have one a one a one so christian 128 plus 64 plus 32 equals two to four or chin i hope i answered your question there chintan if i have not let me know and we'll go back to you i want you to make sure you got it so in chin because we were dealing with a slash 27 and a slash 27 basically the host per subnet is 256 minus 254 224 minus 2. what does that realistically mean in terms of hosts two to the five minus two two to the fourth is sixteen to the fifth is thirty-two so yeah two yeah two two to the fifth is sixteen minus two which gives you 14 addresses so the way this is going to look for a slash 27 is as follows you are going to have a 172 16.1.0 all the way to 115. then you're going to have a 190 172 16.1.16 all the way to 31 the next subnet then the next one is going to be 172 16.32 all the way to dot 47 then the one after that i'll be 48 all the way to 63 and the one after that will be 64 plus 16 which i think is 78 and it goes on and it goes on in the code zone when you're teaching the course and responding to four different messages all at the same time sometimes your arithmetic and your head gets a little goofy so apologies for that but i'm gonna make sure you're there and okay now here's a special use case a slash 32 this is called a host address this is what this looks like in binary terms 1 1 2 3 4. this is what it looks like over here now this is only only used for what's called a host address or a loopback address only only only but let's talk about what that really means where does this subnet begin and end it's going to end and begin on a single address why this is a slash 32 32 so how many addresses are available on this subnet how many we don't have 128 we don't have 64 we don't have 32 we don't have 16 we have one so we've got one available use for this subnet so for this 172.16.1.127 that's the whole network the whole thing so the only time you will ever ever use a slash 32 in your life is if you put a logical address to identify a host only one host on that subnet so you guys get it now let's now deal with uh this one this 192 168 1.17 let's take this let's look at it so first it's a slash 28. so what does that really mean 128 plus 64 plus 32 plus 16. somebody do that math for me so i don't have to be mike the mathematician somebody add 128 plus 64 plus 32 plus 16. and that way i know you guys are happy learning cloud architects out there and great andrew kumar fantastic great gopal great dirk great theo nick perfect bellwinner awesome tell well okay good job nice job you got it 240. great adele great bellwinder you guys are making me proud gonna make the the coach actually so happy he's gonna cry okay really great job so it's gonna have to be divisible by 16 and it'll come our great job so where do you think this subnet begins can you so the 192 168 1.17 just like on great java reeves uh around around william wallace j dark awesome the real thrilled thrill at a room you guys got it now so slash 240 what's that look like let's go let's knock out these four last bits swap them over to zero how many hosts on this slash 28 real host and ip networking not aws or gcp networking that number is going to be different and we'll walk through those problems soon so 2 to the 4th minus 2. i'm sorry it's 2 to the uh yeah two to the fourth minus two that'll tell you exactly how many addresses so 16. great job adele so if we know that it's 16 and this thing's beginning at 17. hmm where does the subnet begins 16 valve wonder you got it right there are 14 usable addresses 16 minus two rand tell you got it nick love you got it and dell you had the right number addresses you just forgot to subtract the network and the broadcast but you've got it william wallace 256 minus 240 will give you um the number of addresses that you actually have hinder kumar you've got one too many two to the fourth minus two 16 minus why because 192 168 1.16 is the network which is not usable and 192 168.1.31 is the broadcast which is again not usable so every address from 17 all the way to 30 are going to be usable addresses now if you're on aws they do something ridiculous they reserve the first four and the last iep address which basically means you'll have 11 addresses why is this so bad if you're planning on using having 14 addresses and you only have 11 and auto scaling runs out of auto scaling addresses then poop your systems don't scale so the slash 28 is 14 available host good job everybody you guys got it so let's do another slash 28 let's do a 172 17 1.19 does this look that much different than the last one i mean we're dealing with a 172 28 versus a 192. does it matter the math identical even though this is a subnetting class b versus applied class c that's why it's cider classes in our domain railing because it doesn't matter so somebody tell me here where does the subnet begin where does it end and what are the usable addresses in the subnet guess what it's going to look a lot like this one over here to the left where we just did somebody help me here work with me somebody help me out here okay um derek i don't see where you're getting this one so 14 are usable correct 16 to 31 or 16 to 30 are the usable addresses kumar 31 is the broadcast so the subnet begins at 16 arun and it ends in 31. the subnet the address you see isn't where it begins where it begins is in these multiples where it's divisible by as whole numbers so 19 if we were to take it into 16 it's one plus change we don't do change when we're dealing with subnet math so it would be 16. so it'll be 172 117.1.16 and then 30 it'll be 16.30 they're usable 31 is going to be all one's broadcast so you're there okay um bowel wonder great job and let's do one more well let's do four more because i know now we're going to do some other fun stuff as a group i think you got it now to a roon but i want to be certain um this stuff is just super critical so we want to know you got it so working through some of these things let's uh um it begins at 16 which is the the network address which the rally is is not a host and it ends in 31 which is if you wanted to send a broadcast exactly so now let's do this 172 17 slash 29. what's 29 look like everybody okay dot 248 or one one one one zero so what is one one one zero add this add this and this add this and this and now you're good so how many times is 19 divisible by eight 9 times 3 is 27 right or 8 times 2 is 16 and 8 times 3 is 24. so i ask you how many times is the dot mean 19 divisible by 8 twice right so bow wonder arun if this thing begins because it's divisible by 8 which is 16 where does that subnet be begin femi good job derek good job alonzo fantastic so you guys get it it's all divisible by two fantastic you guys get it so now wow let's look at this 8 times 2 equals what number everybody nice job uh delaney nice job suba well actually silva you were almost there gary don't worry you can learn this you don't need to stay on retail you can do so many things don't be sad put the effort in nothing good comes easy i will tell you this if it was easy everybody would be there because it's not easy that's why you have the opportunity to put your time your effort your heart and really focus your mind on something for six months to really master it and when you master it watch your life get into incredible things so i expect good things to be hard nothing good is ever easy if it was it wouldn't be good it would just be average so exactly uh william wallace got it derek got it um nick glove got it it's going to start at 16 that's where the subnet begins because it's divisible by 8. so it begins to 16 and it goes up to a total of eight but we start counting at 16 so we've got 16 17 18 19 20 21 22 and 23 like derek from my team says there carrie you just put in the time you put in the effort we can all achieve anything we want anything it's just don't quit why do they put navy seals through the most miserable training in the world and why do they put sas commandos in the most miserable training in the world because they want to push them to see who quits and those who quit don't achieve it do you know who stick around in the end the winners so when it's hard you got it i read 75 000 pages of reading just to become a ccie in six months i felt sick every day i threw up three times right the day before the exam out of anxiety but i did it so don't worry about it you've got it take a couple deep breaths believe in yourself you can do it i promise you you can stay strong that's how people get to good goals one of the navy seals that i know very well said to me said i would never do this because i love elephants he said if you have a monstrous task like an elephant eat it one bite at the time little by little by little you take one thing you win you do the next thing you win you do the next thing about it you know what some days subnetting is easy some days subnetting is not right watch this another day and today if submitting's hard go learn about virtualization you'll get there fight hard fight to win and achieve everything you've ever dreamed and then write me an email about how great your career is because i know you can do it and i want you to get there curry never quit until you find until you get your goals so that's the way i live my life so now we're here so you guys figured this one out now let's do the next one 10.0.0.2 30. so what's that subnet mask look like it looks like this what does it look like in binary terms it looks like this so if william great if the division is even we're going to start at that number if it is not even we're going to start where it would be even so in this particular case i'm not really sure where you're out there philip houston um so what's going on here for this 10.0.0.2 30 let's talk exactly about what that is it is a slash 252 exactly a rune so now i i updated the bottom but not the top yeah i do the bottom one not the top so exactly slash thirty two five two here you've got your one so two usable addresses great job freak mode where is the beginning of this subnet we're actually on the zero subnet here so if there's four total addresses minus two which are not usable where does the 10.0.0.2 subnet begin where and where does it end or what are the usable addresses okay adele you're almost there zero is the network dot one and dot two are usable and dot three is the broadcast so rand good question we can have a network that have 10 different 20 different kinds of subnets on the network and we always will always will william wallace you got it perfect now if two hosts want to talk to each other they have to be on the same subnet if they're not on the same subnet they actually can't um they can't communicate with to each other without going through a router so if you've got a 192.168.1 size 24 and a 192.168.1.2 slash 29 on the same subnet they can't talk to each other because they're on different subnets but okay nigel you got it um an adela del you got it jay you've got it talani okay i want you to watch this again and i think you're gonna get it i've watched you learn so much so fast so either you're going to get that or wouldn't keep we're going to keep doing examples i know it's going to click for you talani now let's go over here to the slash 24. next this is what this subnet mask looks like now this one's going to be pretty easy to calculate in your head you should know where the subnet begins where the subnet ends 2 to the 8th minus 2 gives you the number of maximum addresses how did i get 2 to the 8th minus 2 1 bit 1 bit 3 4 5 6 7 8. so that's the only way i did it so what does the subnet mask look like add this plus this plus this plus this plus this plus this plus this and you get 255. so here's the subnet how many hosts on this subnet 2 to the 8th minus 2. what's that number you got the total number of addresses that are a room but we can't use the zero or the broadcast okay this is a slash 24. 2 to the 8th minus 2 or 256 minus 0 minus 2 254 addresses exactly so somebody tell me where this subnet begins where does the 10.0.0.9 begin 24 and where does it end where's the broadcast nice job adele 1 to 254 they're the usable addresses so where does this subnet begin meaning the one which is the address that's not usable adele right beneath the one what's that subnetta dell 1 minus 1 equals that's your subnet and what is broadcast you got it spell wonder is 10.0.0.25 so that's the broadcast so where is and adele zero you got it is the subnet 255 is the broadcast and the usable addresses are 1 to 254. fantastic adele great job gopal bow wonder fantastic freak mode great arun you got it nigel great job all you guys so super proud let's do this last one on here and then we're going to start doing some more fun stuff we may be going up and down and then we're going to start designing systems together and then we'll be putting some addressing schemes for the system now let's talk about what this is going to look like 10. 30. what is slash 30 it's this one two three four five six six seven eight bits one two slash thirty want this plus this plus this plus this plus this plus this slash thirty two to the set two to the two to the second minus two how many addresses is that total usable i mean two to the second minus two total addresses versus usable two to the second minus two is how many usable addresses dell great job too so now let's work through this situation 10.1.1 30. two usable addresses the one beneath the used first usable address is the subnet the one right above the usable address is the broadcast somebody tell me what the subnet address is in the broadcast address for this zero to four total two usable so now which one of these are where is the where's the subnet where does it begin and where does it and where's the broadcast okay zero to three are all addresses adult perfect can't the zero is the subnet the three is the broadcast so adele which two are usable in between them arun you got it um nick you were almost there zero is the subnet three is the broadcast between wireless one and two are usable zero is the subnet three is the broadcast if i wonder you got it i got the broadcast and chai ten you did a great job support you're almost there zero is the subnet one and two are usable and three is the broadcast great job alex you got it one and two are usable amarf good job there and william uh zero is the subnet three is the broadcast and one and two are usable addresses and derek you got it it's a slash 30. so now we just broke subnets down from big network to little networks but what if we wanted to go the other way now why would you want to go the other way so let's say you're working on a cloud like aws you would do it for lots of reasons other than aws but normally speaking when i connect to the internet with a big internet router i'm using bgp and through bgp if i connect to 10 different internet service providers i collect three quarters of a million routes through one internet service provider three-quarters of a million routes to the next one three-quarters million rounds three-quarters million routes in the end i'm taking in about on a normal internet router you know seven to ten million routes because these routers can handle it now when you're dealing with aws they only let you do 100 routes so think about this 10 million in an internet router 100 routes with aws so basically aws has handicapped you about a million and one percent over the capabilities you would have off of the cloud so you guys all know that i love the cloud because the cloud enables business agility the cloud enables auto scaling the cloud enables three um speed and the cloud enables people in the developing world to buy technology they never had before but don't think the cloud is as good as the network in the data center because it's not it's slower it's a virtualized network in a data center when you virtualize something you reduce its performance and that's okay now there's times where you reduce performance a little bit and there's times where you basically say we can only handle 100 routes let me tell you if you deal with enterprise any enterprise organization they're going to have 50 000 internal routes 100 routes is nothing it's almost a joke and it's actually a joke of a joke that's so silly so when you're dealing with these environments and we used to actually have to do this like 10 years ago or 15 years ago back when routers had a 10 megahertz cpu and a mega ram or 2 megs of ram or even 16 megs of ram we had to deal with small routing tables now we haven't had to do that in 20 years because we've dealt with better routers but now with aws we have to reduce our networking capabilities basically 20 years worth to go work with them so okay so we've got to summarize routes what does that mean it means taking routes and creating new routes that equal the same thing so now let's look at this particular environment let's say we're here let's say for example we've got this 192 168.0.0 adam 192.168.1.0 now i could send uh this route in one subnet as an advertisement and i could send out this subnet okay actually before i talk about route advertisements let me tell you what they are so let's say i'm here derek you're on this call derek i know you well so let's say for example derek is at his house and i'm at my house and we set up a bgp pairing session between us bgp is a tcp based routing protocol that's used to connect to external entities and exchange running information is scalable when i connect to derek i could send him or let's say i have the subnet 192.168.0.0 and 192.168.1.0 i could send him two routes and say derek come to me for 192.168.0.0 and come to me for 192.168.1.0 if i send him two routes i use up two routes no normally speaking no big deal aws 100 routes to route to connect to two people you got a problem so does anybody think that you could possibly go the opposite direction as super heading and literally go up one level for example and instead of having a slash 24 create a subnet that would include these two things can anybody think about what that would look like give you a hint 192.168.0.0 0 and the dot1 could be summarized as this with a slash 23. this address will literally provide reachability for both and what's that something that's going to look like it's going to look at 255.255. that's what this mask would look like now i still got a bunch of other addresses what if i wanted to send a single route that included 192 168. one does oops didn't mean to do that i'm gonna get out of this because let's say i had all these things and i wanted to send a single route can anybody think of a of a new um subnet mask that what i'm so slash 20 i'm sorry this is this should have been 254 here this is what happens when you do math in your head while you're you're teaching communicating and responding to messages in a chat window trying to see things so this is going to be a slash 23 um which summarizes the zero and one what if i want to go zero all the way through three oh ran you got it slash 23. william you can always watch the replay um piano lessons and skills anytime we learn it makes us better in any way should perform that's great thank you for attending and look forward to seeing you in another day so can somebody tell me what kind of a subnet mask we could use for 192.168.0.0 that would include all four of these subnets can anybody tell me come on somebody okay exactly a room slash 22. so by doing this by changing this to a slash 22 exactly everything's gonna change so it'll look like this and what is a slash 22 six bits what are those six bits let's add them up 128 64. actually i don't i don't want to confuse you guys but getting too complicated um but uh we can summarize the one to three with the slash 22x1 now let's do the same thing for these 10 subnets now this is these are going to be a little trickier because not all of these things are going to be easily divisible actually i'm going to make them divisible now let's do it over here for the 10 subnet what's the summary address that gets the zero and the one together eric it was great actually great question we used the slash 23 to cover the first two because the 23 gives us two we use the slash 20 to 22 to cover all four so it's just a matter of how many that we actually need and it's because these are contiguous subnets i hope you got that uh eric if not we'll we'll find a time so exactly we're going to use a slash 23 but what does that slash 23 look like somebody tell me what this slash 23 subnet actually looks like that encompasses these two somebody write it out in cider notation for me cider notation just to let you know would look like 172.16.0.0 16. i intentionally took that cider notation whereas conventional notation would be this well dot zero dot zero and folks i'm really sorry for sitting behind a slide presentation for this sitting behind a presentation without seeing someone is not something i like to do like to be out there front and center like a real presentation would be it's just that i had to use certain slides for some of these numbers so somebody help me here um somebody tell me the cider notation for this exact block 10.0.0.1 what's it going to look like a rooney got it but write it out for me put it in the chat window what is this thing going to look like if anybody doesn't know i'll pop it in the chat window for you yes exactly that's the slash 23 but i want the whole subnet armor what is 10.0.0.0.24 and 10.0.1.0.24 combined to both the subnet and the mask i need something with the ten dot something and then the subnet mask if you guys don't know i'll do it um so i'll help you folks with it what does this aggregate summary look like because this is basically with the summary route that you're going to see on your router it's going to look like this as follows it's going to look for the slash 23 as a 10.0.0.0 23. so what we were doing before is we were going from big to little now we're just going the opposite direction from little to big so okay so let's take a step back if you guys are struggling with this let's go bring this back let's go to 192.168.0.0 slash 24. how many hosts in this subnet there's a 60-second delay so by the time i speak and the time i see your messages could be a minute later i mean you guys got the subnetting now we're trying to do super netting okay exactly you've got six minus two so two fifty four and a slash twenty four what if we needed to subnet the size double the size what if we need to double the size of a slash 24 let's say we need 500 hosts instead of host how do we go the opposite direction so when we subnet were we making something big so if we need 254 usable hosts we use the slash 24. if we need 126 usable hosts we use the slash 25. if we need uh if we need 512 hosts what do we do we can't take the slash 24 because it only gives us enough host for 254. we need to go to a slash 23 to get to 512 that's the next available thing so that's why we go subnet in the opposite direction now what do we need if we can't do it but because of broadcast but what do you would you do if we needed a thousand hosts we can't get it in the slash 16 right um so we can we can't get another one we can't get into slash 24 if we needed a thousand hosts we would need to do a slash 22 because the slash 24 gives you 256. a slash 23 gives you basically or 254 gives you basically uh 254 times two what if we need to double the thousand twenty four we'd use the slash twenty two so that's all we're doing is we're just going up versus down before we were going down now we're going up so if i were to say 192.168.0.0 253 or four hosts 192.168.1.0 that's the next subnet up and that's 254 hosts and we did 192.168.2.0 that's 254 ml hosts and the 192.168.3.0 that's 2584. so 254 times 2 equals what times four i'll do it i'll pull out my trusty rusty iphone with my great max skills 254 times four 1016. so that's where we got to the slash 23. that's how we did it now i'm sorry not to get this so now let's let's look at this 192.168.0.0.22 help if i could type so now we see where it's coming from i just went in the opposite direction so slash 24 is going to cover the first subnet now the next subnet down is this 192 168.1.0 so we need a bigger a bigger a bigger thing to hold this root in this root so we we have to go from right to left this time before we went from left to right to shrink it now we need extra host bits so instead of the subnet mask looking like like this for each one 255.255.255.0 we need one more we need to steal a bit over here so we're going to steal a bit over here by making it a 2-5-4 so now we have our eight bits over here plus a single bit here so realistically what's going on we've got nine subnetting bets or nine host bits so what do we have over here we have eight plus eight is sixteen plus seven what's 16 plus seven it's a slash 23 that's how you got there no different now does everybody see how this and this now equal 192.168.0.0 let me go no guys before we move on to more complicated topics rental you got it good nick love you said it starting makes sense adele said you got it eric no um alex you got it we're almost there so eric let's take a look at it another way sure so bellwinner i'll do it one more time and then we're going to keep building on this so 192.168.0.0 plus 192.168 now these are contiguous subnets what do i mean by contiguous we go to the zero subnet the one subnet the two subnet the three subnet all the way until we fill them all up so if we needed 254 hosts we know we're using that slash 24. so for the top one we have 255 but we now need something bigger something that's got a lot more hosts now we need something that's going to have double that size because we now have to include this and this so how do we do that we just steal a subnet mask and then we cover these two now let's say we want to go from zero to one to uh two and it is two fifty four row not two fifty five because you can't use the zero and you can't use the broadcast so 256 minus 2 is 254. so 0 plus 1 plus 2 plus 3. so let's say we need a thousand addresses in the subnet well we know when we have 254 with the class with the slash 24 we know we basically have double that with this we know that here by here we gets us to say 750 and here this gets us to roughly a thousand how do we put a thousand things in a subnet what do we do well we know 24 is 256 or 254 and we know a and slash 23 is 254 times 2 so what if we need double the size of the slash 23 we borrow another bit so that gets us to a does anybody know what subnet mask is going to cover all four of these subnets what network and mask is going to cover it in both cider notation and official decimal notation slash 22 meaning two five five two five five two five two this one thing now covers this so with routing i can send an address that's called a summary address or an aggregate address and all the aggregate address is it's a single address or a single route that encompasses multiple things and we're going to dive deep into this later glad you got it bellwinner a lot of you guys are getting it now i'm super happy so that's why we're doing this so four addresses just got reduced to a single address aws only lets you have 100 routes you better get real good at this 100 routes is nothing it's like zero i mean it's like a 50 000th of what you're going to find in an enterprise it's that minimal so you got to get good at this this is why your ip addressing and your subnet plan becomes so critical so what i'd like to do assuming we have time is show you how to submit plan your enterprise on the cloud off the cloud hybrid cloud multi-cloud so you guys all know exactly what to do but in order to get there we've got to get good fundamental understanding of the concept and if we don't get it here at all today don't worry we will have a ip addressing design webinar i'm happy to make it i just want to know you guys get it so now let's do the same thing um with these first four over here right now 10.0.0.10 and 10.0.1.0 can any tell me a summary address that's going to include these first two subnets how do we summarize or aggregate the 10.0.0.24 and the 10.0.1.0 with a single subnet or a single route what is this going to turn into somebody help me here pretend i'm bad at math and i could use some guidance okay 10.0.0.0.24 10.0.1.0 24. how do we summarize them and are they really any different than the 192.168.01.1 okay amra we're gonna summarize it to a slash 23. amrith now put it down write it down what that's going to look for eric it's the same problem with different addresses exactly we're going to give you two identical examples and then we're going to basically boost it up a little bit so eric good job you figured it out so chintan i'm wrath type in this box what that whole thing looks like what is that address it's 10.0.what in addition to just the subnet mask and eric you're right if we do all four it will be a slash 22. you're already on the next one but what's it all looking like looks like this sorry slash 23 for the two two of them and if we want to get all 10.0.0.0 all the way through 10.1.3.0 then it's going to be this and if we want to go up more i'm going to accomplish all five it's going to be the slash 22 what's that slash 22 look like i'll pop it in here for you okay great job now somebody who's good at math now i want you to take 10.0.0.0 all the way through 10.0.0.7 how many is that one two three four five six seven it's actually eight um somewhere along the line now we must have cut and pasted something a little funny actually oh i see what our team did here okay so let's uh i can see what our graphics team did here bear with me a minute that's why it's confusing a lot of us bear with me while we correct this i didn't notice this before okay so now how do we summarize 10.0.0 24 all the way to 10.0.7.0 24. what kind of a cider mask would this be how many will support eight slash 24s eight slash 24s what's that all going to look like somebody give me a mask for that and then and then write it down in cider notation slash 21. great math ran now round since you got it write it down insider notation in the chat window start with the subnet and then add the mask so i know you got it all bound wonder great job same project [Music] anybody somebody help me out here what is the subnet i see the mask but what does the subnet extra look like derek you're right it is going to support uh 20 46 ip addresses absolutely the subnet what's it all looking like the the network includes a network plus the mask what's the network that aggregates 10.0.0 all the way to 10.00 21. what's it look like is it a 192 168 something is it a 172 16 something or is it a 10 something help me out here before we get to the advanced concepts do that's what it's going to look like still going to be the 10.0.0 you guys are just giving me the mask i need this network and the mask because that mask could apply to any network i need the full full thing you don't just use the name of something.com you need a fully qualified no name name www.gocogcareers.com you guys are giving me the subnet the sub the suffix with the subnet mask but i need the whole thing so 10.0.0.21 fully qualified domain name www.gocloudarchitects.com thank you thanks bell bender by the way i just want to make sure everybody gets it so that's why i'm being super defensive asking questions now why the slash 21 good question eric because we're taking a 10.0.0 plus a 10.0.1.0 plus the 10.0.2.0 at 10.0.3.0.10.0.4.0.5.06.0.7.0 so we have to combine eight subnets two to the third because we're stealing three subnet bits that's how we got the slash total when we borrowed three subnet bases because we need basically we borrowed three subnet bits because we're basically taking multiple subnets and combining them now if we were all to make them in a single subnet it would be a slash 21 now we're actually keeping our subnets still at 254 people we're just aggregating the information so what it's really like eric is let's say that you uh live off of a single off of a highway let's say i live up right off of highway 95. now what is summary route basically is saying when you come to mike's house get on i-95 and get off at exit 118 which is gatlin boulevard the summer route basically teaches you how to get close to me it's not going to give you my address it's going to get you close to me so the summary route is basically i give you one thing and it gives you as much intelligence that you need to do to get 99 of the way and then when you get to 90 of the destination then it's like you turn on a different gps that's like how do you transfer through the world to how do you get to mike's house so the summary route is just an aggregate no when you aggregate information you lose information it becomes less specific it's much more specific to say right right side of the room 192.168.1.0.24 and 192.168.1 0.0 24. one on one side one on the other side no big deal that's more specific but if all i have to say is hey to get into my house all you need to know is these four addresses then poof that's all you need to do so that's kind of where i'm trying to show you how this works eric i think you got it now we're aggregating eight so let's now look at really bad ipad dressing schemes really bad i'm gonna show you why this is bad let's say for example you use 10.0.0.0.24 in your network 10.0.0.2 to your network tends up deer.sleep dear.sleepthresh network and 10.0.1.0 24 in the cloud this is example of what not to do why can i now send a single route to the cloud that includes 10.0.0.0 10.0.1.0 10.0.2.0 and 10.0.3.0. can i send this route to the cloud is that is that a feasible route for me to send why or why not i can't use this by the way why can't i use this why can't i send this route to the to the cloud does anybody know why this this addressing is so bad okay nobody gets this is 10.0.1.0 along with 10.0.0.0 10.0 and 10.0.3.0 all contained in this 10.0.0.22 okay we just did this 10.0.0.0 10.0.1.0 10.000.2.0 and 10.32 and 10.0.3.0 are all encompassed in the same route so if i want to tell the cloud hey by the way i have 10.0.0.22 and the cloud also has something in the same place does anybody see a problem like overlapping conflicts here yes so if i were to do something like this and trust me i've seen this done many times and this is bad ip addressing and when this typically it comes from it's come from a non-networking person that's doing the ip addressing and you can't use the summary row so i can still make this work but now i've got to use these three routes over here plus this route how many routes can you have in your vpc 100 i've just used four of them and i haven't touched anything yet so we can't do this this is a example of what not to do let's look at it differently now this is properly addressed we've got the 10.0 subnets in our data center we've got these 172 16 subnets in the cloud how many routes do i does the cloud need to send to the data center to encompass all these how many routes does the data center need to send to the cloud to accomplish full reachability what in each direction does everybody see the difference between using summarizable addresses and non-summarizable addresses you guys get me here please let me know by typing cloud architect if you got it and if you don't get it instead of typing cloud architect type i need help [Music] okay i'm just letting you guys know there's massive thunder lightning outside my home right now i live in florida we're in hurricane central we've been getting some massive storms so i just heard and saw some massive thunder and lightning i saw the lightning and with an attempt within a second i heard the sound what that means is the lightning is within a thousand eighty feet from my my house so if my power were to go out at least you know i'm not trying to be negative hopefully it stays up i just that's the possibility i'm just warning everybody right now so nick got it i love it you told me with cloud architect adele didn't get it that's okay we're gonna do this again dell when we took 10.0.0.0 and 10.0.1.0 and 10.0.2.0 and 10.0.3.0. remember we summarized them into 10.0.0.0.22 do you remember that adele yeah our thunder may go away in five minutes unless it's like yesterday which took out all my systems for about an hour um okay so adele you saw how i got here you did it before it's the same thing all we need to do is tell the cloud hey by the way i'm the holder of all these subnets you guys just did it now let's go over here you guys just did this 172 16.0.0 172 16.1 172 16.2 and 172 16.3 didn't you guys all aggregate that into 172.16.0.0.22 okay so we'll go back to some more submarine plans before we uh get into this intelligent um alex i know you're three quarters of the way there and now i'm wrath you don't knock this you can't knock this this is not a not problem this is a routing problem this will work let's go back to this bad ip addressing scheme if you don't summarize the routes and the data center tells the cloud hey i have 10.0 10.2 and 10.3 and the cloud tells the data center i have 10.0.1 everything's going to work perfectly because they're not overlapping ip addresses they're an overlapping cider range ip addresses are still unique we don't need not the problem is is we can aggregate or summarize all these routes like we did here in this environment because if we do this if we tell the rest of the world i have this if we tell the whole world i have 10.0.0 10.001 10.0.2 and 10.0.3 but we don't really own 10.0.1 because it's sitting somewhere else we're going to tell the whole world reach me for a subnet that doesn't exist that's the problem so we need to design our ip addresses in a way that we can send the minimum number of routes why do we care about setting the minimum number of routes we can only do 100. so you need to actually probably be better at your ccie level ip addressing scheme on the cloud than you would actually in the data center because they limit you to 100 which is basically zero normal enterprise seven million routes on the internet they're connecting and you know maybe fifty thousand internal subnets that's kind of normal aws a hundred max you've only got a hundred so you've got to find ways to aggregate them together and if your addressing is not good you can't do it so all we did is we went from here where we have sub we have we have we can't summarize why can't we summarize because this overlaps with this that's it this is inside of this because this we can't this guy the data center can't tell the world i have 10.0.0.0.22 because he doesn't the cloud has the slash has one of these subnets he's basically telling the world i have it that's kind of like me going to a store and saying i have everything made by apple with the exception of mac pros and macbook pros which are sending to another store what's going to happen the whole world's going to come to me for the apple mac pro and macbook pro because i told the world i have it but i don't have those two things they're sold somewhere else so if i tell the world i have it they're going to come to me versus the people that have it so the whole reason you're doing this is basically just to make sure that you have the best information and as few words as an architect you want to take a 10-hour course make it a 2-hour course because that's what your executives are going to hear when it comes to routing tables the less routes and the routing tables the less computation on the routers so they work smoother kind of like anything else if you could read a thousand page book that has the information you need in five minutes because it's five pages versus the never ending story which is going to take you forever to read i'm not saying it's not worth reading the neverending story at all i've never read it but you know people like it i've never read an album in my life but i'll tell you with typically two or three books a week that improve my performance in some way shape or form but i don't read non-fiction i don't read fiction i just don't have time for it but again it's good so what i'm saying here is design your systems and your communication paths ahead of time so let's go back to this example now does everybody see how right here all these routes are made by the same summary address that you guys made previously and all these routes are made by the same summary address and that's why we only need to send one route in each direction so we're going to do it this way i'm going to give you a little more then we're going to break out the whiteboard session and on the whiteboard we're going to start working it through one at a time we'll design systems i'll make all you guys give me some answers and we'll get there so going back to this here are some guidelines that i'm going to give you if you're dealing with router loopbacks you're using the slash 32. what does the slash 32 for a router look boot back look like it looks like this that's a loopback address on a router it's a slash 32. best way to identify a router come up with a unique loopback that's typically what you're doing so after that wan link slash 30. why slash 30 for a when link you've got two hosts the router on one side the router on the other side what is a wind link it's going to be a slash 30. what does that look like it's going to look like 1.0.0.0.30 meaning the usable ip addresses are going to be dot one and dot two the uh my screen is gone yeah it's intentional alex i wanted to get in front of you guys to talk to you um that's why i got out of this and i'm using the chat box so for a slash 30 it's gonna be two five five two five five two five five two five two so a wan link is gonna look like this and a land link just because the slash 28 is the smallest you can use in the cloud don't use it i promise you what's going to happen in the cloud when you use the slash 28 which only gives you 11 addresses you're going to run out of them autoscaling is going to kick in you're going to need more servers and after you kick in with more servers we're going to be in trouble why are we going to be in trouble we don't have enough ipa addresses so it's not going to scale so slash 24 for lan slash 30 for when and oh by the way slash 32 for loopbacks if you can remember that then you completely completely completely understand derek i intentionally stopped sharing my screen i want us to have more of a conversation now versus people just staring at a blank screen or the powerpoint slide um we'll work out things more when it's appropriate i'll go back and start sharing my screen again i intentionally showed it so now that you know let's talk about mapping it together let's have a little fun with this let's work on some whiteboard sessions so let's do some whiteboarding and what's it going to look like deal with it here so now we're going to have some white boarding stars now in this white boarding session i want you to think about the following maximize truly maximize the addressable use space that you have and minimize the number of routes so let's take a data center and a multi-cloud let's say we've got our data center let's say we've got aws over here let's say we've got gcp over here let's say we've got direct connections to one on aws and another one and another direct connection to gcp and we're using multi-cloud because we don't trust one cloud provider we want some redundancy we're going to have a primary connection and a backup direct connection because we're not using the internet this performance is too slow for us so let's say we have this now let's look about how elegantly we can do this what if for example we use the 192.168.0.0.16 address space in our data center by the way this is good we're showing you how to do it the right way now let's assume in aws we use this 172.16.0.0 amaranth you heard it right slash 24 for land slash 30 for win and slash 32 for loop pack you got it now let's say over here in the google side use the cider range of 10.0.0.0 16. now inside of gcp we can create as many subnets that we want in this 10 range which might be a 10.0.1.1.0 it might be a 10 dot zero dot two dot zero you guys see where i'm coming from it could be a ten dot it could be a ten dot 1.0.0 so all these subnets are constrained in the slash 16. and but assume they are but realistically speaking from a routing perspective if you know that the 192 168 subnets are all in the data center and you know that the 172 16 subnets every last one of them is an aws and you know that uh the 10.0.0 16 is sitting in google how many how many subnets does the data center need to know to be able to communicate with these two people with the cloud aws and gcp how many companies how many subnets need to be on its routing table from aws and gcp well let's go back to mike's example let's go back to uh let's say alonzo is coming to my house iran you got it two routes that's all i need to know so the way these summary routes are going to work is i want alonso to come to my house wanted to play with one of the toys i have in the house i like alonso i know alonzo well he and i like similar kind of toys so if i invited alonzo to play with some of my my toys in my house that he would enjoy playing with i might just give him a summary that says get to gatlin boulevard all right better yet i might give him a summary route that gets him to the security guard at the front of my community that checks like the checks ids that's the summary route now once he gets to my community and he gives his driver's license to the security guard the driver's license are going to say hey to get to mike's house make a left make a right and here's his address that's what routing is that's optimal routing optimal routing is this i know to get to aws to reach the 172 16 subnets now once i'm there aws has its own router that's going to know how to take me to which subnet in my vpc because it's like the security guard that tells alonzo once it gets to my community make a left make a right like a metric right and stop here the house with the cat out front that's always meowing and the cat out front that always says hello that's probably mike's house mike loves his cat i love my cat so you know that's typically the way these things work by comparison let's say a rune's over at google and i want to go to roone's house i know to get to his to the to basically his province and canada where he's at now once i get to the province in canada i got to go through customs and let's say customs gives me directions to a roon's house again that's what's going on so we only need two subnets from this perspective does everybody see how home only knowing two versus all the subnets constrained inside of these things could minimize the overhead of the routing table does that make sense to everybody you guys get this if you can let me know by uh letting me know yes i get it or no i don't because if you don't i'll try explaining it a different way and if you guys get it i'm going to move on to more more advanced concepts this thunder is really good ryan you got it that's good guys are quiet are you awake alex you got it classy good job derek okay nick good arun good job shapoor wow i'm feeling really good um i drew four links amrat because i wasn't actually including the subnets on the when i was just including what you needed to know from aws alonzo it's clicking great job okay so let's let's minute let's move these numbers around while we're still using good ip addressing schemes we just moved our numbers around for argument sake if you're at the data center now i know to reach aws i need a route to 192.168.0.0.16 and i know to reach the gcp at 172.16.0.16 now in this gpc vpc we may have this we may have a 17172.16.1.0 and we have 172.16.2.0 we may have a 172.16.254.0 we could have all of this stuff so that's our slash 16. we get to manipulate this object which is networks and this octet which is subnetdex that's and uh sometimes i'm drawing things with a blank so if i'm drawing things on the fly if i occasionally make a little math hour you can you can tell me i've done this for 28 years but you know in the middle of looking at comments we can always make math errors so 172.1 oops 172.16. three dot 16 slash two for it uh with a with a two with a two two four eight which is uh slash 27. so i could have any of all of these subnets here but all i need to know is to get to a room who's like google get to a roon's house and once i'm in a roon's house a roone's house has a router that's going to give me the subnets to reach every destination i have so that's realistically speaking what's going on here you guys get it this time mostly got it last time this again is the right way to do it now let's say this let's say we designed this like a nightmare i've seen this all the time these are the people that don't have a network background that are designing subnets and they're going to have things and they're going to look like for example let's say you have the 10.1.10.0.1.0 and then we have a 10.0. let's assume these are all slash 24s and let's say we have a 10.0.0 dot dot 8.0 let's say we have a 10.0.54.0 and these are all slash 24s now let's say you know in gcp we use the same same cider range but we didn't use overlapping addresses we're just in the same cider range so here we've got a 10.0.2.0 24. and at 10.0.3.0 this is my typing is pretty ugly my typing is terrible and let's say we've got it over here a 10.0.53.0 24. and let's say we're really bad at this um and we for example we had another 10.0.0.0.16. and let's say you had this and this same one doesn't have overlapping addresses but it's got 10.00 and 10. slash 24 and you've got a 10.0.5.0 slash 24 and then you've got a 10.0.56.0 24. i'm going to tell you right now all your communication will work because there's no overlapping ip addresses i'm also going to tell you i've seen this a thousand times in my life this is always happens when a non-network person designs the network always now what does this look like to you now in this data center can aws send me a 10.0.0.16 can google send me a 10.0.0.16. can google say i own every single subnet from 10.0.0.16 all the way to 10.0.255.255. can aws say i have everything from 10.0.0 all the way to 10.2 to 0.255.255. can my data center say hey everybody i own 10.0.0.0.16. can i do that or do i have a problem because everybody's using the same aggregate range so the only thing i can do here is now send every single subnet everywhere to everybody now if i do this and we've done nothing i've got one two three four five one two three four one two three four so basically speaking we've now used up eight and five as 13 addresses and we can't now configure our google routes so we've used 13 subnets just for this now let's go look at our links we need a subnet for this we need a subnet for this we need a subnet for this link and we need to submit for this link so now we've used 17 subnets for nothing literally nothing we haven't addressed remote users we haven't addressed firewalls we haven't addressed ids ips systems that we haven't addressed dmz's we haven't addressed anything we've already used up a fifth of all our potential routes on the cloud doing nothing that's why you're addressing seams is so important a good addressing scheme will make you traffic engineer through your network a bad addressing scheme will keep you from traffic engineering a good addressing scheme will let you do trap we'll let you determine things with bgp how to get from point a to point b a bad addressing scheme will keep that from happening so ip addressing is really really really important not important so that's why i want you to understand this i will tell you i have been working in networking for since 1993 i've been a ccie since 2000 80 of all networking problems that i've ever dealt with are when pc where systems admin people design ip addressing schemes because they don't understand the ip addressing and they don't understand their reality so when i and and you know this is something i've been debating about talking about the community i see these course providers that have never worked in networking in their entire life and they're telling the world i've got an advanced networking course you can learn networking from me and they've never worked in networking in their entire life they're going to teach you how to create these disasters how do i know in 25 years i have done more fixing these disasters than any other design so when you take a course whether it's with me whether it's someone with someone else go to their linkedin profile if they have a networking course then they're not a network engineer and they've never worked in networking don't buy their course it's going to confuse you that's why i don't have any devops courses why because i'm not a devops engineer why do we have network architect and and cloud architect and cloud security because of the three things i'm an expert on do i have somebody that's got 17 linux certifications that's worked at red hat since i coached them years ago making a linux for cloud architects course yes i'm not doing it this person was senior at red hat because they're experts at it when it comes to uh devops i've got two devops people that have spent more than a decade each building a devops course devops is not architecture but it's still good so when you get something and you get training look at the source of the offers what have these people actually truly done in their career if they're not networking people don't buy their networking course if they're not a security people meaning working as a security architect with a cissp or ceh don't buy their advanced security because they don't know security so i just want to make sure that we all get access to the right information to the time so i don't teach what i'm not an expert in because it's not fair to my customers but ninety percent of the e-course providers that are there do so i'm just saying that if you see a networking training and i encourage you to get networking training i'm happy to provide it you can also get it from cisco press you can get it from juniper press we are the people that come from it i spent a decade at cisco and teaching systems engineers at cisco so whatever the case is but when you're getting this training make sure for your career you get it from reliable sources whatever they may be same thing i don't go to a dermatologist which is a skin care doctor to deal with my heart thankfully my heart's good knock on wood but i wouldn't do so i wouldn't go to a cardiologist to deal with a problem with my feet and i wouldn't go to a non-network person to make me network training and i wouldn't go to a programmer to teach me medicine it's just who i am so it's just my recommendations for you but you see what we did here we used a good addressing scheme in a bad addressing scheme so let's work these through now let's come up with an environment i want you to tell me how many subnets are going to be needed so now let's say we've got a data center actually let's do this let's say we've got a switch the switch has 16 vlans on it now what is the vlan the vlan is when you virtualize a switch so realistically speaking you chop a switch into 16 switches so let's say you've got 16 vlans in one switch a router over here which is a layer 3 device got a link we're going to say this is a layer 3 switch what do i mean by that it's going to be a switch slash router so let's make the switch on the other end a layer 3 switch and let's add a wan link from the router in the center to this next switch can anybody tell me how many subnets i need right now at minimum okay so every vlan is a broadcast domain which means it's constrained meaning other users can't see each other's users that are in different vlans because each vlan must be on a different subnet so let's go back to this link i've got a layer 3 switch which is a switch with a router in there so not 16 port 16 switches okay so um chin 10 you're pretty new so let's do this let's say we've got a switch let's say the switch has 100 ports so i'm going to make it we're going to do a vlan example for you let's say in the vlan we decided to constrain it and let's say we put ports 0 nick you're close but you're still missing two subnets so let's say we have the accounting people here let's say we have the finance people here let's say we've got dev over here let's say we've got security over here so chen 10 you know how virtualization enables you to take a bare metal server attach a hypervisor and then let that hypervisor chop that physical server into multiple logical servers now when we're dealing with the vlan all we're doing is we're taking a switch and we're chopping it out to additional switches so let's say you've got additional additional logical switches so let's say you've got 100 ports in the switch you might put ports 1 through 24 in the accounting vlan 25 to 49 in the finance vlan 50 to 74 and the dev vlan and 75 to 99 sitting inside of the security vln i hope i made that clear for you so each vlan is going to be in a different subnet so christian with um that's what i meant by that so somebody was really close when i said how many vlans how many subnets 16 each vlan needs to be on a different subnet so 16 vlans now they're separated by a router if they were separated by a switch it would be different they're separated by a router what do you need when you connect a router to a router you need another subnet which is going to be a slash 30. now you need a subnet connect this switch to the router but you need another subnet because every interface like arm up arm down what does that they used to have a song walk like an egyptian by the was it the go-go's or was it uh was by one of those bands years ago where they had arm movement moving in funny directions well router's like an arm got an arm up and armed down and armed sideways around this direction and each interface needs a second one so dark houston 16 for each switch plus two for the routers beautiful you got it now let's change this i want you guys to get it now let's say we've got 48 vlans on each side it's common i've seen switches with 100 vlans on them they were basically wan interconnect switches so everything was on a separate subnet it was the bangles that's right alex yes i think they were the same people that made the six o'clock already in the middle of the dream the was that manic monday uh wish it was sunday that's my fun day that kind of thing alex now you got me on the bangles um so alex 96 plus what's missing you're there 48 for each switch but we got to connect them to the router so 48 plus 48 is 96 class you got it one for each one link congratulations you got it we need 98 subnets for this good job now let's do this let's give you real a bit of a dose of reality and a lot of network environments let's say let's say you've got a big router and let's say you've got new york and why off uny office let's say san francisco let's say you know what let's have some fun let's say montego bay pick a city in jamaica you know what let's pick two other cities we have a tremendous number of students in let's say we pick bangalore right we're just going to keep with the four because that's all the space that i have probably should have said legos probably got more people in legos than san francisco so let's say legos okay so now we've got you know a wan link now let's say in new york we've got a campus with 25 000 people and 100 subnets which is nothing literally nothing so let's say we've got 100 subnets here let's say we've got a smaller office in lagos nigeria let's say we've got 50 subnets here let's say ryan who's usually in who's in montego bay and ian and malik some of my students decided to go to jamaica and build a data center out there and there's 25 uh well actually some of them are already there and 25 25 subnets here and let's say we've got a huge r d facility in bangalore and over here we've got a thousand subnets because we've got lots of data centers now let's say that we've got lan links going from here to here okay and now let's say let's say this is the this is the main data center we're not we're not doing 1q tagging or trunking here we're dealing with layer 3. can't use lyrics you can't use trunking when you're dealing with routers well you could but you wouldn't and if you want i'll go i'll show you guys the difference between trunking and routing in order to have the same vlan on two switches you'd have to trunk but that would violate a lot of the security and things that we want to do so we're not going to do that there's a time and a place to do that though so this is traditional traditional setups um let's say we've got 500 vlans in the data center okay somebody tell me the minimum number of subnets required and actually let's put a loopback address on every single router so this is going to be 1.1.1.1 and this is this router's loopback address is going to be 2.2.2.2 because you're always going to have a logical address in your router 3.3.3.3 which is a pretty common way to do it and that will people identify things and let's say this is 4.4.4.4.4 and let's say your data center's loopback address on its router is 5.5.5.5 failed great having you watch the rest later we'll see you in class on friday um great to have you here today so how many subnets here william wallace okay so what did you do you out you out of you added the 10 000 plus the 25 plus the 50 plus the hundred plus the 500 so somebody do that and then we're going to add the rest of the subnets that everybody's forgotten about so just for the vlans we need 10 000 plus 25 plus 50 plus 100 plus 500 so for the vlans themselves we need 10 675 subnets again this is nothing in a real enterprise now what other subnets do we need well every every loopback needs to be on its own subnet so we're going to add four more or five more so that's five so it's ten six seven 5 plus 5 but we're not done yet we need a subnet for this link this link this link and this link so add 4 more so now we need 10 684 subnets use now let's pretend you want to send this to the cloud you have a problem you got a huge problem they only let you give them 100. so because of that william you actually did fine i think your error was that you uh didn't see that bangalore was ten thousand subnets and you had it as a thousand so this is how fast these networks grow now can you summarize this and send an aggregate gut route to aws i don't know if you addressed it intelligently perfect you'd be in great shape everything would be wonderful but if you addressed it wrong you'd still you couldn't summarize these things and you're going to have these things so you want to connect to the cloud you only have 100 roots well you got to get there so everybody got that and what and why so like a volunteer from the audience i'm going to have you uh do a subnet and a reverse subnet of a subnet anybody want to take a stab at this i mean i'm happy to keep babbling um but uh i'm always in a position where i i i'm happy to keep babbling all day long i'm a babbler it's fine by me but you know i'd like to get you guys engaged involved have some good time learn lots of lessons so anybody in the audience want to be a volunteer for the next lesson okay i'm waiting to see if anybody's interesting a room good job i'll have you do it i always love your motivation it's fantastic and to some degree it's infectious to others which is fantastic so let's do this room and then alex you got it next i want to make this an interactive lively experience i want you guys becoming experts alonzo that's okay um you could do it another day today you don't have to be the victim another time will make you and then derek awesome so okay somebody here's what i need you guys to do let's start with this 192.168. and then i'm wrath sure why not let's have some fun so let's say we've got this slash 16. i need you to here's what i want you to do um arun i need you to to as efficiently as possible break this down into another subnet and then break that subnet down to accommodate 10 when links so we're not because we don't if we if we use the 192 168.0.0 16 and we put it on a single wamp link we've used up all 65 000 potential addresses so i want you to efficiently break this down into something for which we can have a link that you can break down into 10 subnets and because you're going first i'm going to help you let's say we get we break this down into a slash 24. we're going to add a 192 168.0.0 16. and i'm going to break it down into a smaller subnet for you and then i want you to break that subnet down into other subnets i'm going to give you the help so the reason i i picked it this way is you know with the 192.168.0.0.24 you know you still have access to the 192.168 network you'll have access to the 192.168.3.0 network and truth be told you'll have access to still all those addresses 254.0.0 again you see where i'm coming from because you get a lot of it so you can break it down and still save so we i want you to take this big class b address basically that we've given you arun and i broke it down into a slash 24 which is the equivalent of the class c and i want you to give me 10 subnets that each have two usable links way on links as efficiently as possible start at the zero subnet and work up 10. so arun i'll even help you with the first subnet 192.168.0.0 slash now from there i want you to tell me where the subnet begins the usable addresses and the broadcast address and then after that i want you to give me the next nine subnets ruin you with me if you're there and you need to take a break or let me know it's also hard for me to tell because there's like this 16 to 90 second delay sometimes okay arun i'll give you a few more seconds and if not i will i will move on to the next person okay everyone i haven't heard from you maybe you've got a little internet outage or something like that so alex alex do you want to break down the 192 168 um and then question you guys can answer as well um so i need the first 10 subnets but i'm going to give each of you guys a chance for a minute so okay so if i take if i need to efficiently create 10 subnets for wan links that only use two ip addresses each what kind of a subnet do i need i need i need a slash 30. so if i if i take the 192 168 where do those addresses begin and end so this particular subnet 192 168.0.0 starts from 192 2.168.0 to 192.168.255.2 255.255. that's the broadcast address can anybody tell me 2 to the 16th minus 2 how many addresses that is it's a pretty big number now if we put that on one interface we can't use them anywhere else because each interface he needs a different subnet so nick you got it christian you love it nick love you got it christian you got it so if i take this which gives me 65 000 addresses and i break it down into this which gives me 254 addresses do i need 254 addresses for a wind light no i need two so i pick slash 30s so my first so i now submitted this into a slash 30. so what are these subnets going to look like let's work our way up 192.168.0.0 30. the next subnet will be zero dot 192.168.0.4 slash thirty the next one will be 192.168.0.8 30. the next one will be 192.168.0.12 30. thanks ron the next one will be 192.168.0.16 30. does anybody see the pattern here anybody know why this miraculously is is going up by four every time no wonder i'm sure you see this pattern by now i know you um 192.168.0.32 32 30. so this is how one single slash 24 would break down they're going up four each time hmm why four we borrowed two subnet bits right two to the second two times two equals four now when we're dealing with addresses we're pulling out two why why are we stealing these two addresses because the 192.168.0.0.30 is the subnet the 192.168.0.1 is usable the 192.168.0.2 is usable the 192.168.0.3 is a broadcast guess what we're now on the new subnet because they increment by four 192.168.0.4 as the network 192.168.5.6 are usable 192.168.0.7 is broadcast does that make sense to everybody guys all with me i know this is some pretty tough uh material there's nothing more dry than subnetting meth the dell i see you got it derek you got it arun looks like you got it um quasi you got it alex adele i'm awfully happy if you guys are having fun let's signal the algorithm and keep let me know you're awake alert and oriented by typing cloud architect in the window and if you have the ability to leave a like it helps the algorithm tell people what we're doing is useful please so please add that if you're comfortable no obligation of course okay arun that's an actually exceptionally good question how did we go to the slash 30 what did i do i didn't want you to start at the 192 168 why because i wanted to be really good alex let me know if you guys are awake tell them type cloud architect while i answer runes question so i didn't want us to use the slash 16 because we would have burned 65 000 ip addresses in a single thing so i broke it down into a slash 24. why because it's a very manageable thing to look at and then i took the slash 24 which gives us 254 addresses and says wow that would be crazy to actually use this specifically speaking for the single set of ip addresses so let's break it down into something further so i broke it down into a slash 30 because they're wet links and on land links you only need one ip address on both sides of the link that's why we used it so that's exactly why we started with one big address we chopped it down into smaller addresses and after we trucked it down into smaller addresses we further submitted for maximum ip efficiency remember there's a shortage of ip addresses so when we have them we've got to be good stewards of them we have to protect what's going on in the network and take care of absolutely one of these things so does everybody get this if everybody gets this does anybody want to take a stab at another one when it comes to your vpc classy aws only allows you to do a slash 28 but there's a difference between wan connection in your vpc but it's true the low the smallest subnet you can put inside your vpc is actually a slash 28 valve wonder great um and then alex i want you to do it bell wonder you seem to be getting this super fast so we'll give alex one more shot alex is doing great alex has learned so much so fast i'm super proud of him and i know exactly how hard he tries and the number of things that he goes through every day just like i do so let's do this bellwender i'm gonna give you 192 168.1.0 but we're going to give you a different kind of network problem instead of having a 0.2.1 link what we're going to do is this we're going to create a link and on this link what we're going to create is going to be a switch and we're going to connect a router three routers to the switch all on the some same subnet so for those of you guys that are not used to old school old school this is this is what an ethernet lan looks like so we're going to call this a lan i'm just going to call it a vlan make life easy now let's say you've got three routers in here all on the same subnet okay so this is a land link and we're going to have a router a router a router and the switch is a layer 3 device so consider this to also be a router so we're going to have four devices on this connection now instead of three this is all going to be in a vlan so battle wonder now we need four host addresses per wan link because we're using multiplayer connections we're using ethernet and we have four routers all plugged into the same vlan so now we can't get away with two ip addresses bellwinder we need to you come up with four per subnet so i still want the first few subnets but now you've got bigger subnets than the last person so we can still take our 192 168 and slash 16 and break it down into this 192 168.1.0 size 24. but now we need a subnet that can handle four versus 2. so before we're using a 30 how many addresses did a slash 30 give us two usable addresses for max can't do that we need four so we have to go up one we're going to move to a slash 29 so by moving to a slash 29 we're going to have a 192 168 dot one dot zero slash twenty nine so slash twenty nine is different than a slash thirty a slash thirty was two to the second minus two right uh slash 29 is 2 to the 3 minus 2. why did we pick a slash 29 because we need 4 host addresses 2 to the third gives us 8 minus 2 gives us 6. so the smallest sum that we could use for each one of these things is going to be a slash 29 sobel under give me the first subnet the second subnet the third subnet the fourth subnet the fifth subnet and and let's work our way up from the first one that i already gave you so the first subnet begins at 192 168 1.0 yes there are six usable addresses excellent bell under so tell me where the the first subnet begins i'll actually tell you the first one 192.168.1.0 is is the network 192.168.1.7 is going to be the broadcast and every address in between the dot 0 and 7 is usable so bellwinder now that you know that which i knew you probably knew before because you're pretty good at math now what i'd like you to do is i'd like you to give me the first eight subnets you can just type them in the chat box no you were right you had eight total with six usable you did great with that so now just help me find the next couple of subnets that are all going to increment by two to the third two to the third that's gonna be the number that you're gonna do each time so anybody want to work with me a little bit on that and find it if the first one goes from zero to seven where's the next one bellbender okay well let's look at it this way 192.168.1 hmm two to the third dot eight slash 29. i'll give bellwinder a minute to get to the next one that's actually technically correct ian that's great good job i'm giving you a bellwinder okay so i'm going to add one more bell wonder and then you'll do the next one up so let's do the next so let's add the next subnet 192.168.1.16. 29. do the next one bellwinder remember my subnet math two to the third two to the third two to the third and why are we not subtracting the two here because we need to calculate everything including the subnet of the broadcast we subtract two to find the usable addresses eric yes the next one is going to be a dot 24. good job eric what's everybody think the next one going up is going to be now it's a little quiet but you guys are doing great so i want you guys to work the problem through i want this to be part of you i wake up in the middle of 32 good job alex i think routes and routing tables in the middle of dreams sometimes i think i p addressing plans sometimes uh good job bellwinder it's going to be 30. actually it's going to be 24 plus 8 um which is going to be 32. remember bellwinder is 2 to the third for the total number of addre two to the third for the subnets and it's two to the third minus two you're always subtracting two because you're subtracting out the network in the broadcast so they're going to increment by eight every time bell winder next one's going to look like this there you go bellwinder now the one after the dot 40 what's that going to be oh there you mean they have a pill for waking up and thinking about subnets and network architectures and design things uh they probably do um so i think it's also the product of literally you know walking into organizations that have never done anything like this before that says hey by the way we're going to do iptv and it's 2001 and we only have seven megs of bandwidth but we need to stream two channels and if it takes more than a quarter of a second to change channels people are going to be upset so good job bellwinder you had the 168.1.48 because somebody else put it there and then you instantly before anybody had a chance went there bellwender and you did 192.168.1.56 you got it slash 29 bellwinder and then the next one would be 192.168.1.56 plus 8 is 64 slash 29 and even for me a non-math guy a verbal guy 1.72-29 great job wonderful i'm super proud great job bell winder great job nick yeah derek i've had so many networking things throughout my career you have no idea some of the things that go through my head and i get calls from somebody they're like hey mike what do you think about this and at three o'clock in the morning i'm figuring out where there's a problem with their rsvp signaling in their mpls path it's just part of life i've been involved in this stuff for so long and actually a room good job you're actually correct we needed four and we couldn't do that with a slash 30 because that only gives us two because we lose the network in the broadcast so good job okay nice job with that so here let's create a web let's say we've got palm beach florida closest location to me let's say i'm here let's say my co is in tampa let's say my close friend who helps me with graphics is living in texas let's say another another warrior buddy of mine who also helps me with some stuff like setting up vmware esxi servers is actually sitting in london and because of this i decided that there's going to be so much communication that i'm going to buy a private line between all of our locations and that way everybody can access my systems so chris and i are going to be speaking i'm through a private line alonzo and i are going to be speaking via private line let's say ian and i are going to be speaking about a private line and let's say each one of these guys has an ethernet where their computers are at saint pete not tampa same place chris that's why they call it tampa st petersburg for people like me that could never understand they just had the two cities in the same place okay so we got a lan let's let's spell it properly so i've got a lan associated what's on the land that's where the people plug in their computers and thankfully most people are not like me where they don't have uh a whole bunch of servers they on servers in their house and gpu is doing stuff throughout their house and about 50 000 btus sitting in a room that's 100 square feet the cool computer is off that so let's say you've got a normal house not my cocoon location so and let's say on my house you've got five lands i think i have a little more than five lands but let's just say it's five okay so there's five lands at my house there's a land in the tampa office a land in the tampa office and then so does anybody remember the subnet size that i told you to use for the land the one that's going to give you enough space to add servers or auto scaling i told you to use a slash something does everybody know what remember what that is okay now about wonder the slash 28 is the smallest you can use in aws but i told you never to use a slash 28 and to always use a slash 24 as your smallest subnet that is my recommendation after 25 years of networking why the slash 28 gives you the following if you're not in aws it's two to the fourth minus two which is 16 minus four if you're in any of these cloud providers they steal a whole bunch of ip addresses for whatever research purposes they desire to use so you can't use them so with aws you can't use the first one first for and you can't use the last one so with the slash 28 which is the smallest you only got 11 addresses 11 subnets addresses on a subnet is zero why because you're going to need one for the router that's automatically going to use one then you're going to need one on a load balancer and one on a server that's three just there but if you've got two servers and the load balancer scale up and the server scale up and you've got at least a web app and database here you can easily run out of it so the smallest on a the lan interface you should use is typically speaking to slash 24 because that gives you basically 240 address or 254 addresses so you're gonna have a slash 24 here a slash 24 i don't know it might be quicker to type than it is to actually try and cut and paste the way i'm doing it and then let's say that all these lands on my systems are slash 24s now we've got a wan link what's the best subnet for a wan link everybody how many addresses do i need on for one interface on my house to talk to one interface in chris's house two people having a conversation how many ip addresses do two people need having a conversation if each person has its own ip address anybody or am i just dealing with a massive delay um which is quite possible over the wide area network okay so let's do this we got a wan link what's what do we use for wan links slash 30 good job slash 30. so this link is going to be a slash 30. this link's going to be a slash 30. this thing's going to be a slash 30. so now let's think about how we can do this in our network let's see let's say we were given the 172.1.16.0.0 slash 16 that this is our cider our slider range and i think there's a pretty big delay between the time i actually type something and the time you guys can hear me right now so it feels like by the time i ask a question and the time you guys are responding is over two minutes so if i asked something a couple times i wasn't aware of this delay now you know why um so let's say that we have this if we put this 172 16.0.0 16 on a single link what happens we can put it on this one link and we've got no more i p addresses we just wasted the 65 000. so we can't do that now realistically speaking let's say this is our own entity and we're not going to do any route summarization in our own entity of course we would but we're not but let's just say to keep this very easily what could we do well the first thing we can do is we need to come up with something for the wan links so i'm going to give myself plenty of room for the wind links i'm going to give my wand links i'm going to take and consume the 172.16.0.0 and i'm going to say 23. why am i going to pick that huge number because it's going to give me a lot of wind links do you want to know how many wind links it's going to give me i can tell you this 0 to 4 4 to 8 8 to 16 16 to 24 24 to 32 all the way to 256 times 2. um and then basically what i'm going to say is for the first wind link i'm going to do a 172.16.0.0 slash thirty this is going to be i'm gonna pop this over here that's gonna be used over here now this next one is going to get another length it's going to look very close the next one down is going to get the 172.16.0.0 select our 0.4 30. so i'm going to pop this over here then let's say i go here for the next slash 30. i'm going to do the next one which is going to be a 172.16.0.1 eight slash thirty now let's say i'm going to take a big jump because i want to be able to aggregate my things so for example let's say we decide to start 172.16.0.0 or zero dot sixteen i'll show this so let's let's say we decide to use this for our our headquarters here so let's zoom so 16 let's do this dot so we've already used 0 and 1. let's go all the way up to 16. i'm going to show you why so we need 10 subnets over here right so let's say we do the 172 and then we do a dot 17.0 and then we do a 172.16.18.0 and then we do a 172.16.19.0 and then we do a 172.16.20.0 and then we do a 170 172 172.16.21.0 i know 172.16.22.0 and a 172.16.23.0 and 172.16.24.0 we needed 10 of these remember anna 172 172.16.20 on a 172.16.26.0 these are the subnets we need for our palm beach data center these these are the subnets that we're going to stick in palm beach let's get rid of these little subnets because it's it's hard for you to see what i'm doing here mouthwash bear with me let's see i've got all these subnets sitting over here can all these subnets potentially be aggregated into something that all the other people could look at for example so they don't have to see all these 10 subnets are they contiguous meaning one right after the other 16 17 18 19 20 21 22 23 24 that is 16. so if we took a subnet that went from 16 to 32 would that encompass all of these and leave us room to add six more subnets of course it would so how would we aggregate or super net which is the exact opposite of subnet these roots well what could that look like what could all this mess be just be summarized as 172.16. now we've got 16 all the way to 31 or 16 all the way which is go which is going to so 16 to 31 so 16 17 18 19 right 16 17 18 19 20 21 22 23 24 25 26 27 28 230 31 16 addresses so where do you think the next the subnet will begin it'll begin with dot 32 but what kind of a subnet gives us 16 potential success that we can put in here we could do a 172 16 dot 16 that what dot zero slash okay a slash 24 is one subnet a slash 23 is two subnets a slash 22 is four subnets uh a slash 21 is eight subnets and a slash 20 is 16 subnets so what would this look like slash 20 what's that math gonna look like two five five dot five five dot two four zero i wanna make sure i got that right 192 plus 64 plus 32 plus eight yep got it right and uh slash dot dot zero so does everybody see what we did here we put all these ten subnets here that's highlighted we aggregated it in the same subnet over here you guys got it slash 20. you guys are doing great i'm so happy literally you have no idea how happy i am so we aggregated it all and guess what we still have space and this is why i picked something also big to add a slash 27 a slash 28 a size 29 in a slash 30. why and even a slash 31 subnet why do we do this i want you to have room to grow because no matter how much you think you have it's never enough probably would have given myself more room to grow in the data center like a lot more but i'm just picking easy math numbers here now how many subnets do we need for everybody's land just one that's it so let's say we do 192.168.0.32 slash i'm sorry dot dot 32.0 24. we got it i hope not you mean to do that and now let's say for the next one we have instead of slash 32 we change it to 33. and now this land is slash 20 is 34. now guess what we can still bring this all the way to two five we can still go to 192 168.255 and then we've still got all those other class cs in the end so we've got lots of usable addresses we were very careful with the addresses palm beach only needs to send one route to tampa texas and london palm beach is going to receive full routing information from tampa which is two routes the wan link and the land link and guess what it's going to receive from texas the wan link and the landline and that's it and guess what it's going to receive from palm beach the wan link and the land link and nothing where does everybody see how we did this how we took an environment we submitted it down we did something with the addresses in a very simple elegant way to be sure to be completely certain that we maximize the use of our address space and minimize the routes in the routing table did everybody get that because if you guys get this we're going to turn into some much more fun routing around in whichever country you're from belgium you got it derek you got it should play it looks like you're doing great alex it looks like you're 90 there most of the time which means over time you watch this again it's going to be completely good for you alex you got it now i'm thrilled okay so you guys got it now let's let's work through one more networking example and we're going to do a little routing little and unsubs not really subnetting but we're going to use all the subnetting together to make this a really good experience for you you guys are doing great very proud of you i can see that some of you are alive type cloud architect to let me know you're there and if you're willing to help us out with the algorithm and leave a like we can truly appreciate that these algorithms track who watches how long people's watch whether they like whether they comment and all these other kind of things so willing to help us out we love it but you know we want you to be honest and true to yourself so don't ever comment or leave anything that you don't feel strongly about that that's true gotta be ourselves we gotta be honest and ethical in everything we do so let's take this situation now now that you guys know networking or at least some networking and we're i'm going to be doing a lot more networking courses and we're going to do a lot more free and we're going to have some paid i'm going to do as many as we can thank you for letting me on the cloud architect to let you know i've been a cisco certified internet expert for over 20 years i'm working with another person who's working on his third ccie and he and i are creating both a a real heavy duty cloud networking program we are also creating a network architect program and they're going to be released very soon and they're really about teaching senior networking skills the kind of skills that a ccie would have to build a massively wonderful cloud networking career or a network architecture career which is a wonderful career and totally related to the cloud my network architectural work on the cloud as senior and distinguished architects literally speaking with no other background they're that good those that i've trained over the years that are working at aws and google and others i've trained lots of these people working at the palo alto cloud the dell cloud the cisco cloud so the networking skills are that important so that's why we're creating so much content around networking so let's say this is our data center now that you guys get the submarine concept now let's go to our vpc this can be aws it can be google it can be azure it doesn't matter the same thing is going to work that's why i always say don't learn a vendor learn the cloud learn the right way so we're going to call this vpc and guess what everybody calls their stuff a vpc2 doesn't change anything that's why i'm not going to put aws or gcp or azure or oracle who cares they're just a service provider all they have is boxes if you're with google it's compute engine if you're with aws it's an ec2 instance it's no different if you want to manage cloud dynamodb with aws with google is called bigtable it's the same it's like which brand do you prefer kleenex or puffs it's the same thing nike or adidas don't get bogged down in the cloud it's silly it's irrelevant get bogged down in the technology that's all that matters that's the architecture piece what is in the best interest of the customer and whether you go to walmart target amazon nordstrom to buy it it's the same thing you're purchasing so don't worry about it you guys make people often make it too complicated so let's say we've got a high availability system now let's say we want to connect to the club we're gonna have a router in your vpc and a router on their cloud now aws would be crazy enough to convince you that their router is highly available because it is completely available and you don't need two connections to the router because it's available here's the problem their device is highly available assuming they don't get hacked or don't have a failure their stuff is hidden but yours is not so one direct connection to the cloud not enough if you put your one direct connection in your router and your router dives you're broken and if you have two direct connections to the same part of the cloud through the same high availability cloud gateway on one router and the router dies guess what you're down totally ridiculous way to do this so if you want to do it the right way you're going to do the way every network architect has done for the last 30 years you're going to have two a primary and a secondary across two routers so it's going to be r1 for you guys in the data center and router 2. now in the cloud you can use their ha device in 1az and there's no way on earth i would ever count on that to work in a second place i would use another ha device and another az and that's how i would set up my connections to the cloud now if we do nothing when you work with aws you run into a challenge what is the challenge you must use bgp so two equal cost links with bgp packets might go from router 1 to the 1az and they may come out the they may go to another of they might let's just let's put this i'm going to make this a little easier so what happens does anybody think this is a good situation because it's not router one sends its data to to the area availability zone one in your vpc and then it goes across the aws environment and then your data takes a return trip through another availability zone to a different router to a different internet through a different service provider this is not this is nightmare this is called out of order packets because the latency on one connection and the latency on another connection aren't the same most likely so if you go out one link and you come back another link you have a problem now with aws what they do is they tell you just a block one link now in 25 years of being a network architect i've never seen anybody do something so ridiculous they always load share across their links you don't pay 20 000 a month for a connection to be there and then leave it idle you use it you load share and you'll do the same thing with aws so instead of blocking a link let's go back to ip addressing and subnetting we've been playing with subnetting today we've been having a ball at this so why why why does mike love subnetting so much so let's say we've got this rvpc is using nintendo our data centers using the 10.16 address space and your vpc is using the 172.16.0.0 slash 16. okay we're there now let's say in your vp actually let's just say so let's keep it aside 16. so let's for example say you've got a subnet of 10.0.0.0.24 and a 10.0.0. oh let me do this right 10.0.1.1 24. let's see these are the two subnets in your vpc i'm sorry in your data center now let's see you go back to the cloud over here and over here on the cloud you've got a subnet of 172.16.0.0.24 you've got a 172.16.1.0 24. now let's say you wanted to load share across these links well here's what routers do routers always choose the most specific route which is more specific 10.0.0.16 which includes these routes or 10.0.0.10 24. guess what the 10.0.0.0 size 24 is more specific and if you don't if you don't know how the more bets the subnet mask the more specific the root is so what if you for example took this length the 10.0.1 and you advertised it into bgp on this link and on the bottom link you advertise that into bgp and so and you're sending these routes you got it quasi the slash 24 is more more uh specific so you're sending these routes to aws google azure who cares it's all irrelevant it's just a store pick whichever store you want based upon the services you need don't get married to any service provider you're going to be using them all there's no such thing in today's world of a single vendor cloud well there's a little but it's all it's all going away i'm a business decision was made that made basically everything hybrid cloud and multi-cloud so all that's gone so don't worry about it now it's a matter of just you know knowing how this stuff works because you're gonna be working on everybody's cloud as a cloud architect now over here we've got the 1.0 now look at this over the top link which has the longer subnet mask the more specific we've told the vpc hey to reach 10.0.0.24 take the top link we also told your vpc via bgp hey best path to 10.0.1.0 was in the bottom link bgp is bilateral so we're telling aws that so aws can manipulate its routing decisions toward us now us aws let's play with this let's do the following a aws can influence our traffic signaling by sending a link to the 172.16 on the top link and the 1716.1 on the bottom link why does that do now this router says wow i know the best way to get to uh 172 16.00 if i top like because i've got a more specific route and in the bottom one we have guess what a more specific route does this make sense to everybody so far because we got a problem in this situation we still have to fix but does everybody understand this so far please let me know in the comments section how we're influencing traffic by sending more specific routes let me know that you got that with a yes or a cloud architect or something and i know there's a massive delay on this link so work with me and it could just be that we've been talking networking so support you got it question you got it derek you got it alex good okay i'm thrilled you guys are doing great now what's the problem in this situation how you guys are all getting it well now we're doing bgp policy everybody everyone so we went from basic networking talking about the bits and bytes of a subnet to breaking down into subnet to route aggregation to ip addressing for iwan and a lan to nail bgp policy in four hours we've done half of a cisco certified network curriculum in four hours guys are doing great i mean this is like a rocket ship pace you guys are really doing great so good now here's the problem if the bottom link disappears this one the subnets at the top if the bottom link disappears these subnets are no longer reachable let's just i'll show you why in a second [Music] so bear with me my mac answers my phone calls um so let's go back into this situation because we're having fun now and in this situation we're gonna have a party if this bottom link isn't there you no longer have a route to the 10.0.1.0 sometimes does everybody see that because the link goes down the route goes down so let's put this link back here and then you've got it i see cloud architecture you've gotten it so let's put these links back because i want you guys to get it so what do we do when we uh need to load chair or a traffic engineer i mean we could do it via the weight we could do it be the local preference as path we can play with the med we can change the igp origin code we can do a lot of things but you guys get i'm so happy you guys we're getting into ccnp ccie level networking on four hours you guys are awesome totally blown away so now what if on the top link we send this really ugly route to the summary address and on the bottom we send the same summary address and now what if from amazon okay alex yes exactly we're sending the aggregate row we send the 172.16.0.0 16. and we're also sending on the top link this 172 172.16.0.0.16. now in a normal environment with everything working prop properly would you if the routers only take the most specific path if you've only got two subnets and we'll talk about what you might actually have to do to if you've got multiple subnets to try and make block one of the summary route links but you know right now we're getting into some complexities so that we probably don't need to worry about for right now because we only have two subnets and they're always going to take the most specific link so under normal circumstances traffic for the 10.0 24 is going to take the top link traffic for the 10.001 is going to take the bottom link traffic for the 170 to 16.0.0 24 is at the top traffic for the 172.16.1.0 for the bottom now i ask you all this does 172 16.0.0 slash 16 that's supernet include 172.16.0.0 on 172.16.1 1.0 everybody does it yes it does so what we're doing is we're sending an aggregate or summary link in each direction why if this link on the bottom goes away gone gone gone gone gone now what exists in the top link we have the specific route for the one that we wanted to take it and we now have network layer reachability through the summary route that says hey to get to 176 anything 172.16 anything take the top link so now we have full backup we've got traffic engineering and backup so i know at the aws advanced networking level they talk about blocking the link and the cybex book i won't talk about what any of those course providers are doing um that are there that have never worked in networking i will totally ignore how they do things because i recommend avoiding those things but the cybex publications are very good we recommend the cybex books in fact we make all free training our certification training for free because we couldn't find a course that we actually liked so we thought we can give you free training courses and you could buy the cybex books or those which are the books that are official by amazon and then you could do well same thing for google that's why we made our training for you because we wanted you guys to have access to the best and that means the official manufacturer's documentation but not necessarily a book is necessarily so good so we wanted to give you opportunities to learn as well so of course and a book from the manufacturer at the lowest cost meaning free from us 30 bucks from them got a really comprehensive certification planning routine with just those two plus we write books for free and you can take them they're all in the link in the description below so now you guys see what we did we're just sending the summary route why are we sending the summary route quite frankly to provide reachability if and when everything breaks so now you get it now you know how we use subnetting how we use specific routes for traffic engineering how we supernet to basically save routes in the routing table how we check traffic engineer by leaking more specific routes now there's lots and lots and lots of ways we can traffic engineer and bgp if anybody wants to learn bgp and you want a bgp day like a bgp walkthrough day type bgp day in the section below and i will find some time to do a couple hour bgp tutorial um which i happen to think is fine but you know it's a pretty it's a pretty in-depth protocol but i love teaching networking is one of the most critical skills for the cloud architect so it's going to help you guys i'm happy to do a free btp day i have been informed by my team to let you know that we have a cloud architect training program that is approximately 250 hours and takes people from typically speaking aws certified to hire although we often work with people that are not aws certified as well we don't care um we have to remediate the people that are certified in best cases to teach them the cod anyway so certified non-certified um the way we teach our course is as follows and most of you guys while i'm answering this are actually my students anyway is on mondays and fridays we have three hours of live architecture training and we have a lot of fun we design systems that are extremely complicated on these days and while we're doing these days and we're doing our architecture training in between classes we have lots of homework assignments and projects to be done things to build the career plan things to build presentations things to help you build a better interview we do these kind of things it's important to us make sure people get hired we have people do labs on our system labs on our systems i mean can include anything from setting up microsoft seq i'm sorry microsoft active directory for building firewalls building vpn devices working with vmware esxi for virtualization building containers building firewalls vpn concentrators and yes all of our students build the cloud because there's no better teacher in the cloud than building one it's one thing to use a management console and look at some other cloud provider and it's another thing to build the cloud so they're kind of the ways we do these things so i'm seeing some work from from search ruth some shapur from alonso from bow wonder from amaranth from derek and adele you guys want bgp we will find a day to do bgb we will talk about the finite state machine we will talk about prepending autonomous system paths we will talk about um weight local preference traffic engineering we will have a party we'll start with the beginning of the protocol maybe we'll make it a four or six hour workshop like we did to this so if you guys like that we'll do it um i love communicating networking things so we'll do some free bgp training ned juanan arun adele derek armrath you got it so to summarize the day um we worked on ip address subnetting then we did some super netting which is something in the opposite direction we discussed classful ip addresses we discussed classless ip addresses we talked about classes interdomain routing and cider notation on binary notation we went from subnetting down to super netting up which is route aggregation when we're done the route aggregation i had you guys work through several ip addressing problems and when you're done that we did some traffic engineering based upon bgp based upon guess what supernetting so i hope we tied all these things together prior to closing we've got 10 minutes left does anybody have any questions for me any questions for me while we close up the day nick you're welcome anybody else have any questions for me you know whether any kind of networking for cloud computing aws networking what a sign or that kind of thing okay well it's gotten pretty quiet welcome bell wonder and thank you so much alex thank you um derek uh so happy to help guys really did great you know shapoor it's a good question um when it comes to aws they do much more behavioral interviews than actual technical interviews like a lot more um but i would assume that you could get asked a subnetting question on any interview anywhere anytime thank you thanks quasi uh omran thank you alonzo um really appreciate everything you do for us as well as your kind words um are were there any subnetting problems in my in gcp i took the google professional cloud architect a long time ago i only spent two days studying for it um by basically just because i knew the cloud i found it to be an extremely easy exam i run and i think there was one submitted question on there just wrath if you uh if your cider block is overlapping meaning they're not overlapping ip addresses so if you're using a 10.0.0.16 in the data center add a 10.0.0.16 in the cloud but in the data center using 10.0.1.0 and 10.0.2.0 and 10.0.3.0 and 100.00 and in the cloud you're using 10.0x.200.0 and 10.0.201.0 and 10.203.0 there's no overlap the problem is you can't summarize your routes which means you aren't going to be able to traffic engineer your traffic very well which basically means you're handicapped so will it work yes will it work optimally the answer is no that's the problem just to let you guys know when you have non-networking people that are doing ip addressing and configurations if they don't know this really well the addressing scheme gets messed up if the addressing scheme gets messed up the routing is messed up and if the routing is messed up you can't influence or engineer your traffic anywhere and everything falls apart carlito way what a great way what a neat term but i haven't seen that movie in ages but i do remember loving it now that they could have used some medical um consultants in the beginning of that movie when they had some ivs taped down the wrong direction and things like that but otherwise it was a great movie okay any last minute questions for me anymore well i'm going to kick it off you know with the word cloud architect in the box if you guys all want to type cloud architect we know you're still alive and and i'm going to say that we're going to close this session out after that unless any of you guys ask any more questions and if you've got questions you want to know that you want to know reach out to us and thank you all it's been a wonderful day i'm going to stay here want to make sure no other questions pop up in the next minute or two and then after that we'll close it out thank you so much john doe um down in a room thank you ian thank you bellwinder thank you for letting me know you're there so shreth great job john doe great job nick love awesome thank you arun thank you chaitan thank you chintun thank you content in that message you sent me on saturday i i you have no idea what it meant to me um shapoor thank you and ian uh the cat's actually doing great thank you amaranth alonzo awesome although i think the cat thinks she's the queen of the house and that i'm just here to serve her um which is probably the case but whatever oh she's like that thanks ian um thank you all it's been a wonderful time to see you for my students i'll see you all on friday and we'll have a really interesting kind of architectural discussion it's going to be a little different this week than we usually do but it'll be fun welcome take care everyone

Channel: Go Cloud Architects

Views: 8,902

Keywords: networking for cloud computing, networking and cloud computing, cloud computing technical skills, networking skills training, cloud architect skills cloud architect training, cloud architect career tips, cloud architect, cloud career tips, cloud career training, cloud as a career, cloud career, aws networking training, classful and classless addressing, what is cidr, subnetting vlsm, vlsm exercises, subnetting, vlsm, go cloud architects

Id: DApvMF5tT2k

Length: 233min 16sec (13996 seconds)

Published: Thu Jul 29 2021