Cisco IOS & DNS | Cisco CCNA 200-301

[Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] and welcome everybody to this great livestream we're gonna have on some of the challenges with iOS and DNS to make sure that if we recognize them where we can prevent them it can save us a lot of frustration for those of you who are brand-new to the channel welcome aboard it's great to have you here my name is keith barker and technically the glass is always a hundred percent full of something it's great to have you here and what we're doing is a bunch of live streams all focused on the CCNA 200 301 certifications we're going through the blueprint taking pieces and parts and elaborating on those and then when we're done and this live stream will pause and then you can take that information you can own it and then we'll come right back and do some Q&A as well if you'd like so it's great to have you here if you haven't already take a moment and subscribe so you get alerts when all the new live streams come out traditionally new streams are gonna happen every Pacific time zone Wednesdays at 4 p.m. Saturdays we call it subnet Saturday at 11 a.m. and then on Sunday for CCNA Sunday and we're just putting them all into the master playlist so if you're new check out the master playlist they're in order you just go right down through them and have a great time ok so our objectives today are simple what are some of the gotchas especially on a new device or if you're new to cisco and a router that can slow you down and cause a lot of frustration and I think as far as a discussion about that let's it's gonna be surrounding DNS domain name system I thought what we should do is before we start you know tossing out DNS and DNS this and do this let's talk for a moment as an educational public service announcement for DNS the domain name system identify what it does real quick make sure we're on the same sheet of music and then we'll take a look at how can drive us crazy at the CLI if we're not careful so let's use this topology right here and in this topology we've got several devices that we can play with it's it's a fun little playground I've got PC one right here which is a PC at 10.16 0.10 it's connected to an access layer switch just a layer to switch and so the reason that this PC is in VLAN 10 is because the port it's connected to that switch port is configured as an access port in VLAN 10 then we have some trunk links that are carrying all different kinds of VLANs including VLAN 10 that goes down these core switches these are multi-layer switches and this core one router or this core oh and multiply your switches switches acting as the default gateway so if we drew this out from left to right here would be the PC and then it's default gateway would be core core 1 and it's not 1 on that Network which is 10.16 dot 0 dot 0 they slash 24-bit mask right there great and then from core 1 going outwards we have core 1 is the next top in the path would be router 1 and so we have a connection here to another router router 1 from a layer 3 perspective and that network here I'll use a slightly different color for that the network there is 10 16 6 wood that's that doesn't look like a 10 Keith I think your numbers are slipping all right 10.16 dot 6.0 at this last 24-bit mask great and then we have another connection from r1 down to this network and that network is the oh you know what let's go a different direction let's go a different direction let's go this way over here to r3 and so we have this Metro Ethernet cloud that's providing basically layer 2 services so it looks like r1 and r3 are on the same logical VLAN or network and as a result they can peer with each other and so forth from a routing perspective so this next segment as we go out to r3 I'll label that it would be the network and I'll use a slightly different color here 10.6 t10 dot 16.7 dot 0 with a slash 29 bitmask okay join us for subnet Sundays and get all up to speed on before addressing and subnetting and then finally we have a client here which we'll put out here as PC to PC two right there and this is the network 10.16 dot 22.0 for the 24-bit mask and that's right here so art so core one is using dot one everywhere our one is using it appears dot five everywhere I'll put that right here for the last octet our three is going to be using dot seven first last octet and pc two has an IP address of dot 101 oh that is right Oh barely made it to avoid my face alright good whoo so that's our our logical topology from a layer 3 routing perspective and so if a PC was trying to access a device on the network if it if if we have a user like Bob who's sitting at that computer and bob says ping to PC 2 let's say he does the name and that also goes for a web browser if we did it open a web browser and we opened up a browser to WWI M behind the scenes the computer that the network needs to know okay you're trying to go to PC 2 but what is the IP address behind that that's the whole story about DNS domain name system it's getting resolving or figuring fancy word wave for saying we're figuring out what the actual IP addresses the network layer address is for a destination and the way we use that with DNS it goes something like this and let's go ahead and Majan PC one is doing a DNS request to try to get to PC 2 so the DNS request I'm gonna put that in a slightly different color over here anytime there's a service on the network there's also a client so think of that as like a yin-yang model ain't and there's a there's a like a webserver there's a web client like a browser HN is a DNS server if there's some type of DNS client which is built into our operating systems so Windows and Linux and Mac they all have a built in DNS client that when a customer requests the name behind the scenes this is ok who's my DNS server I'll go out and make a request and find out what that IP address is behind the scenes and that's how DNS operates so let's imagine for this discussion because it'll be a great review as well that our DNS server this is the guy or the gal who has all the information about names and IP addresses and DNS servers on the internet cooperate and so there's a hierarchy of DNS servers so if one server doesn't know the answer it can actually go upstream and ask another server and it can ask another server they call that a recursive query behind the scenes it basically means we make a DNS request for a name like WWWF a site comm and it gets resolved or we get an answer back that says hey here's the IP address or addresses that you asked for so let's imagine that PC one is using this DNS server one ninety two dot one sixty eight dot one dot one hundred so if that's the DNS server my question for you is and I'd like you to chat this in in the queue what how does this PC know the IP address of its DNS server I mean what what is the most likely way that this PC and possibly thousands of other ones know about the DNS server they should use if they ever need to resolve a name to an IP address hmm now most of our devices on the networks are not manually configured that's certainly an option we can manually configure the IP address and the mask and manually configure the DNS server but as I look over the queue I see the first one to the gate this Aaron way to go DHCP brother DHCP the dynamic host configuration protocol and in that process the client boots up if it doesn't know an IP address yet it says I need an IP address so it says a discover and then the DHCP server hopefully if one hears or a relay here doesn't offer client requests it and then finally there's an acknowledgement and then the client gets that IP address with all the options including here's my IP address the PC so happy here's my IP address here is the mask and here's the DNS server I should use and here's my default gateway all delivered via DHCP and great answers from those who responded to that so so we have a Adina server configured or learned it is this right here let's imagine that Bob is sitting at this computer and he is gonna do ping space in fact let's just let's not even imagine it let's just go ahead and do it let's go ahead and go to that PC because I have it in my lab here so we can make a road trip this is that PC and that's all sighs funky hold on a second display settings I want it to look nice and we're gonna tell this to go ahead and it's not that advanced 1280 by 720 is currently what I need this to be for this moment so I will go ahead and apply that and keep those changes check my feedback monitor yeah okay great so here's that client PC and one thing we would want to do is just verify that this has the IP address we think it does so we'll do a we'll go to a command prompt now it doesn't matter if you go to the command prompt to the GUI or if you're using PowerShell of some flavor but a command prompt is the command prompt we'll do an IP config and sure enough it's got the IP address of 10.16 dot 0 dot 10 its default gateway is 10.16 dot 0 dot one and we just check our diagram real quick and let me bring that back up so our PC right here has default gateway is 10.16 that 0.1 its IP address is dot 10 ok it looks that all looks good so let's go ahead and do the rest of our configuration or rest our test if we want to see how we learned this IP address or how it was configured or if we want to learn more information such as the layer 2 address which isn't shown by default the MAC address on this interface or we also want to see information like who is the DNS server that we're supposed to using we can do an IP it's not show it's IP config space forward slash all just like that and what that /all says please show me all the details including who the DNS server is which is a problem because that's the wrong DNS server so this is also going to involve a little bit of troubleshooting as we make sure we get this correctly setup so let's let's do that too let's let's make sure this network is going to function because it has the artena servers right here one ninety two dot one sixty eight dot one dot twenty four and our clients currently pointing at some wacky address I don't even know if it's reachable ten will just write ping ten dot well it's you know it's not my DNS server anyway so whatever it's pointing to we need to correct that so one way of doing that in the GUI depending on the flavor of Windows you have you'd have to and Windows keeps morphing and with how you configure the basics but we're gonna go to the properties of the network adapter with whatever interface Microsoft has given us and this version I can just right click on the interface go to properties and double click on Internet Protocol version 4 or I can highlight it and click on properties either way and then here in the properties of the ipv4 interface I can specify that I want the DNS server to be one ninety two dot one sixty eight dot one dot one hundred if I want it to work alright so that's done and let's also verify it trust but verify somebody said that a long time ago IP config slash all and there is our new DNS server so if this computer ever needs to make your Reza use to ask somebody hey I'm trying to go to PC to do you know the IP address for this it's gonna try to use this DHCP this DNS server to do that so let's go ahead and do it it's do a ping actually one of the cool tools because when you're working with network environments it's it's better to be familiar with several tools on different platforms and on many computers as an option called nslookup and nslookup is fantastic is it stands for a name server lookup and if you want to see if your name servers working you go and that's lookup space and then you can actually press enter and it's interactive practice with that when you have a few minutes but nslookup space and then pc to dot and the name you're looking for and what that did right there it made a request out to the DNS server and said hey I'm looking for PC to negate lab comm this is the DNS server that responded and this is the answer that it gave back to us that that IP address that corresponds to the pc2 nugget lab comm is 10.16 22 dot 101 great so that's that's working now that's a huge step in the right direction and also if you haven't done so already one of the really a great learning tool is called packet tracer for hands-on practice with Cisco and another tool on a Windows environment that you can get they also have a free Linux - is called Wireshark and Wireshark is a protocol analyzer so if we wondered like what protocols does that use for the DNS requests how does that work what ports are involved we could capture it and I think because we're right here and I've got a little button right there for Wireshark on this machine this is just an example of a packet capture program that's capturing all the traffic on this network interface card of this PC at the moment so I'm gonna let that run in the background and just do that same command again and this lookup PC - new globe comm and that actually so one of the things too is that if you're ever concerned like oh did it really go to the DNS server that time or is it cached there's also an option of IP config slash display let's see here display DNS display oh cool so that's the right command it's just empty you can see what's cached locally on this computer to verify whether or not it has learned a name to IP address mapping and locally caching it versus going out to the DNS server but it's empty there's also an option for IP config Oh says could not display the configuration of the instrument that mean it was empty hmm-hmm let me just double check something real quick I'm gonna go ahead and launch this command prompt as an administrator and do that again IP config slash display DNS okay it's just empty I want to be sure that wasn't just a rights issue and we can also if we did need to flush the cache maybe the PC had learned incorrect information we're gonna start fresh there's also an option for IP config slash flush teenis yeah anyway if one of the things you can do is you do a ipconfig space slash question mark and that just gives you all the help and they can just go through and say oh there's all these commands options all these options I can do including flushing the DNS cache and and displaying the dance cache and so forth so the capture has been running the whole time in the background so let me let me do one more so it'll be near the bottom we'll do a nslookup for PC to nugget lab comm our DNS server responded and it's all captured right here so I'm gonna I'm gonna click on stop here this capture oh it's only 122 packets not too bad but I'm gonna filter the output just so I don't have to sort through everything manually because time is important here so we'll do a DNS and what that does that does a display filter it's only going to show us DNS related packets regarding the DNS protocol and I'm gonna scroll to the bottom because I did that nslookup near the end as well and here it is right here so in packet 1:16 here we have the application layer service of DNS and here's the query it was saying hey I'm looking for oh dang that's good so what this query is in measurable terms is looking for a quad a record that's an ipv6 it's asking hey do you have an ipv6 address regarding this hostname and if we go up 2 packets up here here's the query and packet 114 that's looking for the a record the a record is looking for an ipv4 address so here's our request so here's the DNS header information that specifies what we're looking for we're looking for the IP address behind PC to negate lab comm it's a standard query fantastic at layer 4 it's using the user Datagram protocol or UDP the source port in this example is 60,000 967 it's just some high numbered port the client said the client this is Bob's computer just said this port is not used let me use this port for this request and then it sent that request to the well-known port of 53 the UDP port 53 that's where DNS servers are that's a match made in heaven so Deena's sorry listening on port 53 looks at it listens opens it up says oh here's what you're looking for and then hopefully responds this is the layer three header the network layer from the tcp/ip protocol suite with the source IP address of our client and the destination address of our DNS server and that layer to this is Bob RPC one source MAC address and the destination layer to address is the default gateways layer to address because it's layer two we got and forward it to the default gateway so it could open it up look at the IP header make a routing decision and forward it on its way so I just want to confirm that that was working and it is so that's great news all right so let's go back let's go back to our our regularly scheduled show here and take a look at our topology it's important not only to understand how it works but also to have a verification occasionally that's working as intended and let me click here and let me hit this button this is what I meant to do so we just watched with the protocol analyzer we just watched the a Bob's PC one make a application layer request so the application layer Services DNS at the transport layer we looked at it using it was using UDP the source port was a high numbered port the destination port was the well-known port for DNS which was 53 at the network layer it had the source IP of PC one and the destination IP of the DNS server and then at layer two at the data link layer if source mac was pc one and the destination layer to address was this guy right here core one because that's who we're forwarding to that's our default gateway and then those this is all in the mind of Bob's computer or PC 1 and then that computer just started spitting that stuff out on the wire at not near light speed but actually pretty close to light speed whatever the the hardware can do as far as spitting it out on the wire so once they get on the wire electricity travels over over copper at like the speed of light times 0.8 I think something just a little bit less that pretty darn fast once those bits start flying and then the layer 2 switches forward it there the layer 3 routers make their layer 3 routing decisions based on IP dress and they forward to their next hop and then we use writing protocols like OSPF to good and train the network on how to reach everything so that's how DNS works PC ones good and now what is the problem what's the problem with DNS and the CLI on a Cisco device and this is one that probably I first started learning about at Cisco back in I think I was like 19 probably 1997 98 98 ish around that timeframe and I probably lived with this problem that I'm about to share with you for over a year there wasn't I mean the internet was new we were using things like gopher and stuff like that back in those days like gopher was that anyway we didn't have a lot of advanced tools and lot not a lot of information so this is a problem that I suffered with for quite a long time too long so once you see it you shouldn't have to suffer with it at all unless you unless you want to and this is it let's go ahead let's go to core one and on core one let's do this you bring up the right screen here I mean log on alright so this is our multi-layer switch core 1 and if we did a trace trace is great let's say we wanted to trace a path all the way from core 1 all the way to PC 2 and I'll just check PC 2's dress which is 10 16 22 101 great so we'll do a trace route to 10.16 dot I just added up to 22 dot 101 all right 22.1 o1 if we do that it's like oh no the network's broken oh no do I have time to click do I have time to go cook top ramen maybe what's happening in the background is that your router by default is doing DNS lookups for each hop in the path so a normal look up is when a client says hey I'm looking for this name I need an IP address that's a normal look up looking for an a record but a device can also do what's called a reverse lookup it's looking for a PTR a pointer record and it basically says hey here's an IP address like of the first hop in the path could you tell me it what the name is behind that and the goal is that it's trying to show you not only the IP packet are the IP routers in the path but also the names by doing reverse lookups oh yeah maybe not quite enough to heat all the water for top ramen but pretty close I'm really three hops out so as for going across the internet the Internet has name resolution and reverse and pointer records that could help us out and give that information back but many times we're crossing portions of a network including our own where individual router IDs are not in DNS and if they are the reverse look-up tables aren't created that's what they're called they have the pointer records in them for doing a ip's name so yeah that was it says is pretty well that would take a long term in there but it it it says the actual delays weren't too long for most of them but it took I don't know it was that a minute for three hops holy schnikes now that's one problem and that's that's DNS in the background trying to do reverse lookups and helping we have the same thing on a PC like if we into a PC and we did this trace RT to 1016 dot 22 dot 101 now we already verified that this PC has a DNS server but the plan the problem is that DNS server does not have each of the hops in the path as pointer records in its DNS table so it's timing out and the clients timing out and and it's not able to feed that information back so it's still definitely slow that's why I'm going to do a ctrl C here that's why on a Windows computer it'd be wise to do a tra ceer T space - d4 don't bother don't bother what Keith don't bother doing DNS and if we do that it says great I'm not gonna bother asking a DNS server so whether you have a DNS server or not depending on how that DNS servers config it may still hold you up for a while so telling it to on the windows computer Italian not to use DNS to resolve each and every hop is a very much more effective way to get that trace done alright so going back to our core layer our multi-layer switch the one problem here is that even if we did set up a DNS server config T and IP name server and we specified our name server it still wouldn't help because that same name server doesn't have all that information in it so one other thing on a shared is this what if we do a typo I know I've never done a typo oh look I did one like 14 seconds ago if we do a typo and we like we type in you know something incorrect like that it thinks we're trying to tell that to that host name and as a result says well you're trying to tell not to this host name I better go behind the scenes and ask a DNS server what the IP address is we don't have a DNS server configured and as a result is broadcasting a DNS request hopefully hoping somebody can resolve that form and this is where it's like oh no oh no oh no control shift 6 control shift 6 control assistant I'm just doing control shift 6 over and over again this is bringing back I might have PTSD especially if you're in a hurry and need to get something done so that name looked up aborted over here on the right it finally took on some terminals it might be control shift 6 X I would strongly encourage you before you're in the moment of needing to break out of a something like that's gonna take a lot of time like this practice your break sequence and it might be slightly different based on the terminal emulation program you're using and how you're connecting to your router but be aware of it and practice it that way because when that's in the moment so painful it's just like is that that's the right break sequence right control shift 6 or is it control shift 6 let go X or well what is it again there control shift 6 control shift 6 X acts or practice it beforehand and that way you'll know exactly how to break it up alright so how do we resolve this one answer would be you could have make sure all your hops your routed interfaces are in DNS and include a reverse lookup zone for them for the pointer records and if you are in good shape with the DNS administrator which I am right here you can go ahead and set it up so you could actually create the right reverse look up zones and you could create the right entries as a records I made this little a record a few minutes before we started the livestream so that one would work I wanted to verify that DNS is working but short of that if you don't need DNS services on a router like you're not using any dynamic look-ups for VPN peering or anything else like that you can go ahead and just simply tell the router just don't do DNS lookups at all and that's the probably the number one fastest solution to do it and the syntax goes something like this no domain maybe its IP domain lookup so in older versions of iOS there was like a domain - lookup and that also works I believe no IP domain - look up yeah it takes either one but if you look at the running config it's the one without the dash in it that takes so for backwards compatibility historical purposes they left both them there but this is the I will leave you with the correct command no IP domain lookup and then if we do a trace - whatever that IP address is 10.16 dot 22 dot 101 it's gonna verify my work there make sure that's the right divide 10 16 22 101 yeah sure enough so we do now a trace there now it's not bothering or even trying to do the DNS resolution it's just giving us the full trace there and if we do this we do a typo it's not gonna try to translate that and and take forever doing it and broadcast for a DNS resolution it's just gonna say yeah I don't know what that is right away now if you do need to have hosts on your multi-layer switch or you need to have resolution if you want to train it to use the DNS server the syntax is IP name server and then you're going to point to the DNS server and there's a test you might want to do a ping to that address now that does not mean that if the ping fails maybe ping is being blocked to that DNS server that secretly do DNS requests but you could also just try a quick ping to PC oh I turned off DNS lookup I'm gonna turn back on DNS lookup so that it'll actually use the DNS server IP domain lookup ok so now it's on and now if we do a ping to PC to dot nugget lab comm press Enter it resolved it to that IP address and also this is this is actually really important to let's say you're having a DNS challenge of some type you're wondering uh are we are we calling to the DNS server or are we caching information for DNS because most DNS clients including routers have that DNS cache where they learn something and they cache it whoo-hoo-hoo I got this information I'll use it again if I need to like an ARP cache a DNS cache so to see the DNS cache on a local router in this case it's a multi-layer switch we just show IP mmm show hosts yeah that sounds like a winner so show hosts shows you the cache and this is simply saying that yeah I know how to reach PC to Google calm it's decided to address it that's because it resolved it from our DNS server just a few moments ago if you want to clear it out I believe the command is clear IP IP hosts let's see here nope it's just clear hosts clear host space and then you can use an asterisk or you can just remove one of them if you want clear host everything let's get rid of all of them and then show hosts and now the cache is clear again so in case you're you're going back and forth and you've got entries that are not correct you could go ahead and flush them you can also make manual entries which is you know in a pinch handy it's like oh this guy's always trying to resolve this like name to an IP address you can just create IP host I'm getting right and then you can put a name in like mm how about PC one PC one is our PC up there and VLAN 10 and then we'll go ahead and put in the IP address which is which is something something let's verify that 10 16 0 10 is that something so 10.16 dot 0 to 10 and I'll just show hosts and there's got see that P erm permanent meaning it's a configured host mapping as opposed to being dynamically learned via DNS so now if we ping PC one it resolved that locally it says I know what that IP address is and then I went for it immediately where if we did a ping PC 4 which doesn't exist and DNS lookup is not running that's just gonna ignore it immediately all right so let me cover let me just check real quick and identify what I wanted to cover I want to chat with you about why DNS may be causing you grief from a typo at the CLI where it's like ah oh it's trying to resolve that or if you're doing a trace and it actually just kind takes a lot of time every single hop to try to do a reverse lookup where it's not working the solutions could be enable Idina enable DNS Adina server have that DNS server with all the entries and the reverse lookups then anything in your enterprise you're trying to trace or reach it would be in there that's a solution but most likely in many environments you just turning that feature off if it's not needed anywhere else is a great way to immediately get rid of that wait time due to typos or trails that happen in the network and that's what I wanted to cover it's a record 30 minutes so here's what I would love to do first of all if you haven't subscribed yet please do if you haven't checked out if you're new to if you're working on your CCNA I encourage you to take a look at the master playlist we're going through the blueprint taking pieces that I feel I can elaborate on and help people understand and get you a good start so if you if you're new to Cisco that's a great playlist to check out also on Saturdays there's a live stream at 11:00 a.m. I call it subnet Saturday focusing on IP addressing we have like 8 videos it are their live streams in there and I'm now including the comments afterwards so if you want that's why sometimes are 2 or 3 hours long so if you want the meat of it this is the first part and then Q&A follows and now on Sundays we have the CCNA Sunday where we cover additional CCNA related topics as well if you haven't yet joined discord and you want to the discord server the focus of this channel and that discord server is purely and simply CCNA cisco CCNA 200 301 and any other topics in that blueprint where we want to just get better share our knowledge clarify our understanding and so forth if there's topics that are beyond the CCNA that you want to cover or want to discuss I have a separate channel in the discord server for other topics so if you have ideas for videos I'd love to hear them if you want to join us the live streams I'd love to have you if you I stay for the QA you're welcome for that as well so I'm going to do this I'm going to take just maybe 30 seconds grab a drink of water for a few moments and then we'll come back and we'll take Q&A now in the QA what I'd love to have happen is this there's been a lot of great questions and answers happening and the QA which is on my screen right there and I'm grateful for everybody who's asking questions and answering questions and going forward if you have a question for me just do an at Keith Keith Barker and select my name and that way it'll highlight it for me if you had a question from like 20 minutes ago but you want to redirect it to me please feel free to include my name and I was gonna go from starting now going down and that way I can make sure I catch any new questions are things you need my direct input on but based on what I'm saying there's just a ton of great feedback happening as well alright so that being said I'm gonna mute my mic well I'm gonna give you a little break symbol here and then we'll be right back for some Q&A thanks everybody [Music] life is a winding road no telling where it goes driving through days and nights won't stop for traffic light okay and I am back and my audio sign that's ooh I'm two for two it is so good to have all of you here let me take a quick peek that's great thank you very much oli for your time you know time is the one thing that we have a pretty big constraint of in the world will have an equal amount some of us have obligations that are tougher than others I get that children work conditions environmental conditions working two jobs sometimes maybe three you know having see Cisco skills but if I look back on my life Cisco skills and the ability to understand how the networks work is probably the biggest fundamental boon to my entire IT career and I started in 1989 90s or 80s are today 1885 Cisco around 98 got my first CCA in 2001 second CCI in 2003 and the opportunity to continue to learn never stops and so I'm now focusing on Sdn software-defined networking and I'm back in the trenches just like I feel like I was just like learning anything new it's like I don't know what that is I don't know how that works so you start slow like every CCNA candidate does you start slow and say okay let me start with the basics let me start with a structure and let me learn piece by piece ask questions but what I've really found the secret to learning new technology is also the secret to good parenting and I have seven wonderful kids I I don't take a lot of credit for all that but they are seven wonderful kids and the secret is not quality of time although that's nice to have it is quantity of time making sure you have time for those kids and the same thing goes with learning something new if I if a person wants to learn something new and they want to be able to describe okay here's how you deep ich request works and at the application layer it's a UDP it's a DNS service and that transport layer it's UDP and all the way down and what the addresses are at layer 3 for IP and layer two for the datalink and weald understand somebody brand new won't be able do that but a person I spend some time can do that and the reason that's helpful is that because in a production environment when push comes to shove and you've seen me if you've been through these live streams with me you've seen me push come to shove a couple times I was like why did that do that and then she's like okay you know what I have some experience here let's go ahead and take the gloves off and find out what really happened and what went on and that happens when we lab things up and have real-world experience and lapping it up in packet tracer or if you are going on to ccnp level and you have the your licensing viral or if you're using online labs from some source that hands-on practice is a is a rebel as an eye-opener and time blocks of time is the secret to really studying and learning so I'm gonna study 15 minutes you see that's not enough time to really grasp something I try to block off at least 45 minutes to an hour and then before I start studying I'm targeted on okay what do I hope to accomplish in this period and then I note it down and then I focus on that and if I reach that goal I think hey I've got a little extra time what else could I do or I plan for the next day set yourself up for success I use I'm 55 so I do some strength training occasionally just to remind my muscles of what they're supposed to be doing and in that light when I do one set of exercises I'm not correct I'm not like over-the-top crazy I'm just an average you know moderate weights but when I when I finish a workout I think to myself okay look at my app a little free app what's my next workout and I look at my next workout and if I'm good to myself what I'll do is I'll say let me sit up the weights for the next workout whether it's military press or bench or pull-ups pull-ups are real easy because the the bar is always there or if it's mmm what else or crunches not crunches squats or deadlifts whatever it is if I take a few extra minutes to set it up in my mind I know my next workout which is in two days I tried it every other day my next workout is going to be based on that exercise and the weights already so it's like oh I have to get the weights nice this is my self-talk and we never have self-talk like that I think oh that's so lame lame self-talk but that self-talk happens like I'd have to you know put on my shorts first and then put on a shirt and you know change my shoes and then go rack the weights just take take the obstacles out weights already get up in the morning have a little routine do it get it done and I worked out today so alright let's go ahead and take a look at questions all right I'm starting with I'm gonna clam up a little bit here he'd bring this mic over alright okay um do mom's asking yo Keith why or why Vegas is so low and networking jobs you know I I worked in las live in las vegas I've been here since 95 long long time and I got my first CCA I was here I built a rack of equipment and vented it out because it's so warm and as far as jobs go I did do several consulting gigs here in Vegas for casinos because they had the money at the time and I also did some for a couple small businesses but I don't know the job market here I don't I know that people who do work in like MGM owns amateur maybe not majority but a lot of hotels here in Las Vegas and so MGM has an amazing IT staff so I don't know what the current opportunity is in Vegas I would rely on tools like dice dot-com and monster in the US there's probably equivalent sites elsewhere maybe those are international and if you're looking for a job entry-level jobs some other job start on those websites look at and say oh I'm not qualified for this or that or the other but find out what they're looking for and if you think you have like a partial shot go for the interview forget the interview it's good practice somebody once said experience is what you get when you didn't get what you really wanted but that's a little bit of joke but if as you have experience interviewing you can find out why it didn't go well and if you find some interviewers after the fact where they didn't hire you if you can reach out to them with an email some of them maybe not all may tell you the truth about why you didn't get hired so culture is very careful in the US about not offending anybody and not being liable for anything that's not positive but you might find a few interviewers who could tell you yeah just your experience wasn't enough in this or that or the other and they can work on that step by step don't try to don't try to go from 0 to 100 overnight it's not good for the system try to go from 0 to maybe 5 on a weekly basis and then by the end of a do the math on that at some period of time you'll be way better off than you ever did nothing at all ok let me see if there's other questions I'm just gonna look for the questions a lot for the comments and the kind words thank you very much I appreciate that quill is asking how do I join the discord server there should have been a link at the very top let me see if I can Oh still my it was still in my clipboard I just posted it so that's the web invite link for the discord server so if you open that in a browser and it'll take you to it and you can join and have a little bot there that will make you a member ASAP and away you go okay I'm working on my CCNA right now says do bond and wanted to know how accurate do I need to memorize the various commands great question I'm getting out the blueprint for CCNA I've got two other ones that I'm working on working on core and the advanced routing and services as part of CCNP but for CCNA here's that here's the guideline of what I would do if I was dying I would go down I would first of all get this document somebody who's not willing to get this document which is free from Cisco go to Cisco comm career certifications CCNA it'll have an option to download the blueprint do that so you know what's there and then go through them and you can also rank yourself not a bad idea rank yourself as far as how well do you know that content if five is great ones that one means I don't know what it is be honest just rank yourself and then as you go to study think okay my goal is to take myself from a1 which I don't know that is to a2 where kind of like I have an idea what it might be by just watching a video or reading a book or chapter about it and then it's just every study session try to move yourself from 1 to 2 to 2 to 3 and an answer directly to your question if it said configure and I'm gonna look at the first example here where I see a configure which is module 1 section module 1 sub section 1.6 it says configure and verify ipv4 addressing and subnetting so I would not only want to know how that works with submitting and you can join subnet Saturdays to master that if you'd like we have a playlist for that here on this channel but I'd also want to be have the experience in configuring it I have not sat the exam yet that's coming up in about a month and a half for me I'm gonna do it before Cisco live which hopefully it will still run because of the kovat 19 the they cancelled one of the last Cisco lives and hopefully the phone and bake is still gonna go anyway back on track a question in my mind because I haven't seen the exam yet would be something like here's an IP address for a device on the network configure router 1 gig 0 0 so that it has the first valid IP address on that subnet that my friends is a great question great question because a person doing that would have to first of all take that IP address and mask using block size and calculate the range of each of those subnets in that area and then boom pick the first address and configure it on the router so you have to understand how it works and be able to configure it I think that would be a fair test and it sounds simple but it be a test of does the person understand how subnet it works and doesn't understand how they tell it and so the configuration portion you need to memorize those commands another example just one more and I'll take the next question is I'm gonna skip to section 3 section 3 is IP connectivity which in English means routing IP routing and it says configure and verify single areas a single area OSPF version 2 which is for ipv4 OSPF version 3 is ipv6 and the OSPF for version 6 is not on the CCNA blueprint but version 2 is so if they said configure and verify single area OSPF I would absolutely need to know the commands to not only configure it but also verify it like show IP ospf interface show IP ospf show IPS IP SPF neighbors etc now here's one of the things I also will benefit you from hands-on practice I use a lot of brief options just just just a ton let me show you so on this multi-layer switch if I'm gonna show I P protocol let's want to see what routing protocols are running okay so OSPF is running here and if I wanted to just get a really quick overview of okay which interfaces are running OSPF and what are their roles and do they have adjacent neighbors and the fully adjacent neighbors in each of those off those interfaces I get a show IP ospf interface brief and oh my gosh there we go so this guy is the dr the b dr for all these segments he has full adjacencies here on every single one of those networks except for his loopback which makes sense and and that's a home run I mean I think oh yeah I can answer questions about this if I need to or solve a problem that's involving this which the thing is a simulator which Cisco in the past and I don't I don't I doubt they would never I'm expecting they'll continue to do it if they're doing a simulator it may not support the brief option so if you show IP ospf interface brief and there's like oh it doesn't work what do I do just don't do the brief just do the full command show IP ospf interface all the data is still there and that's where the benefit of hands-on and how much should I know I would say memorizing just commands is not the way to go get packet tracer it is free download it from netacad get a free login account use packet tracer and get comfortable with labs with practicing setting up OSPF verifying OSPF and and what you'll discover is that you with your hands-on practice if you really know it which you will from just some hands-on practice you'll be able to answer those questions even if a simulator perhaps that they're giving you the testing environment doesn't support every possible command that you would have always used like like showing the air the OSPF router ID a couple different ways of seeing that seeing the area that a router is assigned to a couple actually multiple ways of saying that including looking at the LSA database but all you need is one right that works and that's why it's just comfortable to be or a good idea to be comfortable hands-on as opposed to trying to memorize certain commands all right also check this out it's gonna help you it's gonna help you in the future like if you go through this practice and you do the hands-on practice as I'm encouraging you to do like like I'll come back to that then as you go on to professional level or you're in the work you're in the environment in a production environment and you're working with the tools those commands they're gonna come back I was working with what was they working with ERP last week I did some content for eh ERP far as part of encore and I hadn't touched EIGRP probably four five maybe six years since I've actually had to play with the edge RP and it just comes back it's like oh yeah yeah yeah feasible successor feasible distance feasibility condition all that stuff successor routes it comes back and that's because I had to practice and I've I've studied it alright don't get off my soapbox there thanks for the question it's worth it to learn it and that way you just you own that information alright practice is asking what is the best way to check what type of cable is connected with a router switch like rj45 fibre or another it's tricky mmm if you have SFP modules so a lot of routers and multi-layer switches have modules that you put at SFP part and it could be copper or fiber and so I would say experience is probably the best one for that because they both are Ethernet copper and fiber are both considered Ethernet interfaces they could both be gig 0/0 or gig 24 / 0 whatever it is but I would say the best thing to do there I think I think packet tracer offers that option hmm that would be wanted to check in packet tracer or see when you put your connections together can you do fibre to an SFP module can you do copper and then do a show command and just look at the outputs and see if they're different if it doesn't support that you could also Google that as well that's a great question that I don't know if the top of my head all right oh my great answer fantastic all right and Mike is asking about updates on the CCNP course release when it's done is done my parts are in - I think I'll be done with all my stuff before the end of March and we have five people working on it so it's a team effort and why the moment it gets released we will let people know thanks for asking I appreciate your interest okay is it possible to have Cisco devices add their host names to Active Directory TNS you know that's a great question I don't think it is so in a Microsoft environment if you get an IP address from a DHCP server there's an option for automatically updating hmm if it can it I don't know the answer that from Microsoft in a Microsoft environment if the if the DHCP server who's well so if the DHCP server that's handing out the IP address late let me back up at one and the two thoughts one at a time if the DHCP server is itself is updating dynamic for the DNS dynamically that would work but very likely our interfaces on router interfaces and so forth are not going to be assigned via a DHCP server unless we did reservations and then they got them based on the reservation based on their layer to address but most the time are our critical servers and our router interfaces and so forth we want a hard code or if not hard coded put in with a reservation for that IP address as far as the dynamic part I don't remember how that works on the Microsoft side if it's the DHCP server that dynamically updates DNS the answer would be yes if the clients doing it a Windows client does dynamically reporting and updating the DNS then the answer would be no all right Chesley 97 if that's your real name I says he is I'm just joking is stating we've enabled IP source card on a wireless access AP ports and now we roaming between APs doesn't work because I learned the IP on one switch port and it won't let that IP yeah that's a great question call tak what can we do to fix that yeah there's there's eleventy billion opportunities for engineers to come in and resolve issues and solve things so regarding that MAC address or that source guard thinking that the other device is lying about where it's coming from oh you can back call that though can't you so if you back all the traffic hmm was that me so in Wireless the wireless access points they all forward their traffic using the protocol to the controller and then the controller actually is the one that has the logical connectivity for the rest of the network access and so if people are roaming between access points I think by default in many environments they it back calls to the original controller so that MAC address doesn't change so if it encapsulates and back calls to the original controller there should be a flap so I would look into shezzy back calling that traffic up for CCNA you don't need to know that everybody but that's what I would look at see if back calling will solve that and Paul is asking will CBT do be doing any SDRAM training we have some st-1 content we have some automation programming content inside of CCNA that network chuck did which is great and then we also have a whole course called Cisco dev net associate which has a boatload of SD in including SDRAM an ox hutchinson so it's a 2 part it's actually three parts but two major parts Ben Finkel walks through sitting help programming works the basic concepts setting up visual studio help the basics of Python yam all and some other frameworks and then Knox comes in and walks you through step by step this is the dev net associate he walks you through how to actually use tools like ansible to interact with everything and automate things and he covers a large variety of platforms including data center legacy iOS devices and wireless firewalls and so you might wanna check out the what we cover there CBT Nuggets is a subscription site it's not free but there's a 7-day free trial and I also believe you can look at the library and just verify what's in it and that would be a good way to find out and test so thanks Paul because I know there's a ton of SD Software Defined Networking content including some st man and the dev net associate training all righty great answers from other people in the queue I appreciate that okay and I don't wanna be saying that the Windows client updates its own DNS and if that's the case the Cisco routers not gonna do that if it gets a DNS if it gets an IP address it's not gonna have the ability to do that thank you thank you all right I don't see any other questions let me give it one more moment in case there's any last questions that come in it there's about I have the default settings for my stream which means there's like a 15 maybe 10 to 15 second delay between when you hear my voice maybe that's tres voice it's so great to have you here and the time that and then the time you response so that the chats are a little bit delayed not based on your fault but based on just how the delay works so if any other questions please feel free to ask our focus in all of these videos is going to be CCNA 200 301 how the network operates how the protocols work and we'll also get into some of the automation and programming as we round out the the playlist so it's on the major playlist is called the master playlist for CCNA it's on my youtube channel our YouTube channel the discord server is available hopefully you'll join them if you have questions or if you have recommendations for a video that I currently don't yet have or a live stream I don't you have there's a six sections for requests for videos for live streams or other so if you have ideas of what you like to see use that and then there's a separate discussion group for challenge questions and your CCNA experience the only thing I ask is just make sure you check out the rules just to verify that you're ok with their rules which basically say be nice don't don't disclose information you shouldn't don't hate and don't share other people's paid content if it's paid for we wanna make sure respecting that but if you created something we had some mind maps that were shared the one of the members created which are amazing I looked I open them up wow that's a lot of work so thank you all for that support as far as fabric path sessions I that's way beyond what I think the CCNA has its first pick so I don't anticipate any fabric path sessions however when we're all done with CCNA we're gonna right now I'm doing three streams a week regarding CCNA and just building that master playlist so if you want to join discord and put that in the other category I'm gonna keep those those are indefinite so as I run out of things that we need to talk about for CCNA I'd be happy to look at other ideas as well so thank you for that request to that question okay Devon is asking would you recommend to proceed to ccnp after CCNA if I want to pursue security career or should I go different certs that's a here's what I would do I would say the CCNA is a minimum qualifier there's a lot of CCNA is out there even with the new one there's give me a lot more but it does validate basic knowledge of basic fundamentals for networking I think what I'd have a person do is do CCNA and then go right to ccnp for the enterprise that's on core the spanning tree at the next level routing protocols at the next level and then also to get a CCNP you have to have two exams the core exam and one concentration the other one that I believe will be the most popular in that light because they they kind of play off the CCNA is I've got a blueprint and I'm not afraid to use it here it is it's the advanced routing and services 300 - 4 0 1 en a RSI and that's those the 3 I me myself and I what I would do right now is I get the CCNA if new Cisco I then parlay that information that knowledge and take it into the CCNP which still focuses a lot on routing and switching now there are other electives to our concentrations you can take but those are the two that are primarily routes which and then after that if you wanna get into security I would probably investigate some ethical hacking courses something to that effect or if you're working with a in a company has a specific firewall product like checkpoint or Palo Alto or Cisco's firepower I would focus on those because if you can start studying and practice on technologies that are likely to be seen and used even if even if the firewall is in place and you're not allowed to change it or do anything if you if you have firepower threat defense in your enterprise somebody's managing that and so if you want to study it you could have something to ask questions of and you actually set up a lab environment and have like a buddy on the inside who possibly can help you with some of the rough spots or how is this applied in our production environment which helps a lot so that's what I've do CCNA CCNP and then focus on trajectory that is important to you that you have close to you and I haven't seen the NP exams yet either so that's it's all depends on how I think they're gonna be fair everything I've heard about CCNA and the DEF net associate has said that it's a very very fair exam meaning it was just right down the line if the blueprint said said this describe this understand this configure this they didn't pull any punches there wasn't too much left field involved okay let me add another question we check that real quick Darce instating I had this issue I'm not sure what this issue is observed when I was able to ping via vrf on my router but wasn't learning the MAC address in the show ARP I opinions I don't I don't know if that's a statement or a question so V RFS for the CCNA world is beyond the scope of what we're gonna focus on for CCNA but a vrf is like a little mini-me version of a routing table so imagine a router has the major routing table that's if you're a CCNA or starting to study that's all we see just one giant routing table but we can carve off little logical routers it's not like a partition but it's not like a subsection and when you say hey you little virtual routing and forwarding instance this PRF you have this interface in that interface and these static routes and it can make its own routing decisions based on its own like mini-me version of this routing table and that's the basic concept of a vrf Sudarshan and your troubleshooting scenario I'm not sure what the full picture is there let me see if there's anything else okay all edgy is asking are you going to be do automating and programming Cisco security solutions 307 35 s Auto I know we're doing n Auto as far as s Auto I don't know if that's on the blueprint at CBT Nuggets my full-time gig or or not so I haven't got that far yet my goal right now is to finish on core and the advanced routing and then we're gonna take a look at what's next so we're pedaling as fast as we can and we sure appreciate your interest so thank you thank you thank you alright I think that's it for the questions in the queue I have I have a lot of fun doing this I I've been doing networking for many many years I love sharing what I know if I think I can provide value or an insight on a topic that a lot of people need to learn like switched virtual interfaces and multi-layer switching which are all in the playlist already I like to do that also with DNS and some of the problems but that can come up with the command line I thought that would be a great topic because people who are new whether they're using packet tracer or a live gear or another simulator emulator that issue about trying to resolve a typo or trying to do reverse lookups for every hop in the past with a trace those are bears so you want to avoid those to save time so the next live stream is Saturday it'll be a subnet Saturday we are in video or session 9 now of subnet Saturday which is involving now we're going to take a look at more variable length subnet masking and some cool tips that can save us time when doing that or if we're given an IP address and we're asked what sudden that does that live in some cool tricks to go right to that that range of addresses and quickly calculate it so we can actually know what the answer is as far as what subunits in without having to draw out 20 or 30 different subnets and all the ranges to calculate it so all that's coming up on Saturday followed by another stream on Sunday this shirt where can I get this awesome shirt I bought this awesome shirt on Amazon I got this awesome shirt so I wear corny and sometimes sometimes funny shirts doesn't always coincide but that's where I got it I got it on Amazon I just do a Google search on search like funny shirts probably a lot of good choices so that's where I got it alright everybody thank you very much for your time it means a lot to me and it also means a lot to the other people on this channel who are striving for their CCNA and here's my challenge for you watch if you haven't already make some time and schedule time to go through the entire playlist fill in those gaps do hands-on practice if you see something do the hands-on practice to verify it don't take people's words for all this is how that works throw a packet tracer lab it up verify it and then once you graduate from CCNA and that's my intent for everybody listening right now I'm talking about you once you get your CCNA and you're thinking oh my gosh I got it the best day ever I worked so hard for this I got the CCNA I would like you as you progress in your career and you go on to CCNP and you go on to security or you go into whatever your passion is I would like you to come back here and help those other people who are just starting and give them a leg up let's let's change the world let's change not change the world let's change a few hundred thousand people's lives one person at a time and it's a collective effort and I've got on discord I think ten or so moderators who are fantastic just willing to you know share time and ideas and I'm grateful for them and you as you're in this room right now also as we go forward if you have ideas let me know in the court tell me what you like to see and I am going to cut this off it could be a record Keith it's like one hour and four minutes six minutes seven minutes alright everybody thank you very very much for your time and attention and I'll catch you in the next live stream hi everybody [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music] [Music]

Channel: Keith Barker

Views: 11,915

Rating: 4.9754601 out of 5

Keywords: 200-301, 200-301 ccna, 200-301 cisco, 200-301 videos, 200-301 ccna certification, 200-301 study, cisco, ccna, networking, cisco ccna 200-301, cisco ccna certification, cisco ccna training, cisco dns server, cisco dns server configuration, cisco dns configuration, cisco dns, cisco dns server on router, dns

Id: 5iTF_bCZg1g

Length: 74min 52sec (4492 seconds)

Published: Wed Mar 04 2020