CCNA 2 Chapter 2: Static Routing

this video is for chapter 2 of CCNA 2 on static routing we discussed the routing process last chapter so the next two chapters we have static routing and dynamic routing coming up probably the hardest thing we'll see in this chapter well depending on your point of view is summary routes aren't that bad but we have to get back into some binary so we'll be setting up static routes going over the advantages disadvantages and why you would use a static route within this chapter alright so first part we have static route implementing so we've already talked about this a little bit that routes can be learned two ways there manually or dynamically so we have a static route that we can set up and they just like setting up a static IP address on our host device and we have dynamic routes and we'll go over how to set those up in Chapter three we remember we've discussed ew GRP OSPF rip those will be primarily the dynamic routing protocols that we discuss in the next chapter you've got a couple different static route and default route scenarios the purpose of them using status static routes in this situation is it's going to decrease the entries in your routing table which means all your router doesn't have as many routes to look through if there's less entries and therefore making decision with the decision making process a little bit faster so you've got our one connected to these two networks over here you see it's not connected to anything else other than these two networks on the left side so these two networks send traffic that's not going to one network down here or the other it's always going to be going out this way so that's when you use a default static route basically saying if doesn't match this network or that network everything is going towards r2 over here from our two's perspective it's connected to these two networks and the internet okay so it can't just say anything that's not going to these two networks I'm going to send out to r1 it is going to use a normal static route not a default static route which would say basically that anything headed towards these two networks goes out towards r1 okay that could either be two entries one entry for one static route for each Network the ten network and the eleven or you could use a summary route which is something we'll discuss in a little bit basically a summary route would be a route thinning income this is both these networks in one static route statement so why use static routing we have a couple pros and cons here and some advantages listed up at the top so they're not advertised over the network that's going to result in better security dynamic routes are shared by default static routes use less bandwidth because you're not constantly sharing routing updates with other routers in your network in your topology no CPU cycles or use can you calculate and communicate routes because you're entering them manually and you're not communicating them the path of static route uses is is known you said you typed it in it's known it's an entry you made yourself dynamic routing protocols it could be going one way could be going another based on the metric it uses to calculate the the best route so you won't always know which path in a dynamic routing protocol that you will with static and you have some differences down here that these are most likely test questions so pros and cons of static versus dynamic configuring complexity increases with network size okay and this dynamic is usually independent topology changes dynamic will automatically adapt to change your network topology or your network setup your static you're going to have to set it up yourself because if your topology changes that's all done manually so you'll have to go ahead and make adjustments on your own scaling of course dynamics going to be better for scaling it'll go ahead and make the changes it needs to figure out the routes on its own again if you're going to scale up with static routing it's going to be more work for you so it's more suitable for simple topologies let's secure more secure resource usage we talked about that up here more resource usage for dynamic routing static not as much no extra resources needed predictability route depends on current topology route is always the same so know those differences pros and cons they are most likely test questions so when to use static routing you've got a couple bullet points here providing ease of ease of routing table maintenance and smaller networks you really wouldn't go through the trouble of setting up a dynamic routing protocol in a situation like this you've only got one network behind your router so setting up a static route off the network a static route from r2 to the network is going to make sense routing to and from a stub network this is a stub network so you can see a sudden network is a network access by a single route so this connection from r2 to r1 and the router has no neighbors you don't have a bunch of other networks out here you just have one network behind your router could be actually a couple connected to the same device but there's only one way off of that general network okay so I shouldn't say multiple networks you'd have a network or a couple subnets of the same network over here and you have one path to and from that network and that's subnets ok so if you have just one edge router here one way off that is going to be your stub network anything behind this router that doesn't have any neighbors a single-use default router represents a path that is to any network that does not have a more specific match within another route in the routing table so r1 mmm this is not the best example I guess but if there were a couple networks over here our one had entries too and maybe item 172 16.3 dot four and a dot five network down here then you could have entries for those networks that are connected to the router but anything that doesn't match you could send out this way so that's what the default route does okay anything that doesn't have a match in your routing table that default routes going to go ahead and catch it and send it on its way so more aesthetic route applications static routes are used to connect to a specific network provide a gateway of last resort for a stub networking and Gateway of last restored is where do I send something that doesn't match any entry in the routing table reduce the number of routes advertised by summarizing several contiguous networks into one static route again we're going to talk about that route summarization process and we just discussed that route static routes are not advertised create a backup route in case a primary route link fails so that's going to be a floating static route that we'll discuss in just a minute that's going to be a static route that you raise the admitted administrative distance of manually which is actually a very very easy process just one number you type in so this is the same setup we saw a few slides back so first for a standard static route that you have here that would be the route that r2 is using to connect to our one again stub network is going to be the network that has a router that has no neighbors it's kind of a self-contained network one path off of it one path to it so our standard static route would be the route from r2 to r1 it doesn't need to use ab a-- dynamic routing protocols is always going out serial zero zero zero and it's next hop is always this router to get to the network over here 172 dot 16.3 okay so that's always going to be its route to that network the directly connected network would be the to network for our two so that would be an automatic entry but you're making a static route to get to that dot 3.0 Network over here okay so that's what you do standard static route from r2 to r1 but to reverse if you're trying to get from r1 to r2 or any other network okay because well our ones directly connected to the dot three network over here the stub network the stub router if it's not going to be well if it's cut to traffic within this network actually in this situation then the only other networking knows about is the one that's connected to our to any other network can be covered with a default static route which is zero zero zero zero with a slash zero Sider notation or quad zero subnet mask that means every other IP address will be sent the direction of this default static route giving you a gateway of last resort for any traffic that you need to send okay so from r1 to r2 r1 is going to have a default static route that says basically anything IP address zero zero zero zero slash zero where again quad zero subnet mask is going to be sent out serial zero zero towards the next hop r2 here and that could be going to the internet it could be going to any other network that is connected to r2 so that's what your default static route is going to do for you that sets up your gateway of last resort and we get to a fun slide next won't get written to it too much just yet but then you have this concept of summary routes okay so let's take a look at what we've got here you've got our one over here connected to well there's no label for this router but you've got four networks behind it essentially okay and you're going to want to set up a static route you've chosen to get to those four networks you could create static routing statements okay for each one of those networks but to get to each one of these networks you're going the same place from r1 to this first router here that's the first next hop that's all our one needs to worry about what's the next hop to get to these networks that's all I'm making a decision on where do I send it then this routers going to make a decision okay I can send it there or I can send it here that's the router over here is job r1 all it needs to worry about is where am i sending this initially then other the other routers down the line will make decisions for me that's kind of like how your home routers work on your home network your home network router basically just says I'm sending this traffic to my internet service providers router then it's going to make all kinds of decisions for me so your home router just has basically a default route saying anything that's not on my home network I'm sending to the Internet Service Providers router and it's going to make decisions ok so not exactly a quad 0 like your home router would be but here you have 4 networks that you could potentially reach by sending to this router from r1 to this router you can summarize those all into the same routing statement by using a single summary route that would encompass all of these networks ok this is going to go back to subnetting and a little bit of binary alright so basically you've got a slash 16 ok which means you have 16 Network bits or 16 ones in your subnet mask and if you take this down to a slash 14 okay so you have 14 Network bits you can actually encompass those 16 in that block of 14 and we're going to go over later how you summarize that but basically what you do is an anding process comparing well just the octet that's different in this case it's the second octet okay it could be the third octet could be the fourth but again we'll go through that process later it's not too bad it might look a little odd at the moment but we'll talk about it in just a second and the other concept we will be discussing and how to configure it is a floating static route that would be a backup route basically in case some link were to go down so in this situation for instance you've got your private LAN that you would be using for some company that you would prefer to use because it's your own line you're only smile you know how are you getting from one place to another essentially it's going to be faster than the internet so that would be your first priority okay but you can set a backup in case that fails excuse me that would use your internet to get to get from branch to your HQ router over here so essentially how you do that is who's setting up a floating static route that has a higher administrative distance and we'll take a look at how to set that up in just a second basically it's the same as a normal routing statement with a extra number at the end that indicates the value you want to assign to the administrative distance okay so we're going to get into setting up a lot of these things right now so this next section we are configuring static and default routes the ones we just talked about it's not too bad setting them up they start with either an IP route or an ipv6 route statement or command I should say if you well if you're setting up either one so just like any other command if you want to switch from IP to ipv6 then you just type in ipv6 so here's what the command looks these type in IP route then the network address and subnet mask that you're trying to reach okay after that you've got either/or and you could do two different things three different things actually total you can type in after you type in the network address and subnet mask the IP address of the next hop on the way to that network or you can type the exit interface okay you can do one or the other or both actually so if we take a look at the next slide if you type in the next hop IP address then only the next hop is specified that's considered a next hop static route you got directly connected static routes which only use the exit interface in the IP route statement and then you have fully specified static routes which use the next hop IP address and the exit interface bolt you will need to use those at in some situations but generally speaking the directly connected route is considered to be better than your next hop route in most situations okay and because we will talk about the next hop route but it has something called a recursive lookup that will discuss here's how the IP route command would look so you're on r1 trying to get to be for instance 1.0 network up here okay 16 1.0 I should say and you type in IP route 172 16 1.0 which is the network is trying to reach along with its subnet mask and then you're going to type in the next hop IP address in order to get there so from our ones perspective you've got r2 r1 and r2 the network between them is 1 7 2 16 to 0 r2 is address on that network is a dot - ok so that's what you're typing in there is the next hop IP address don't get that confused and try to type in the IP address of your routers interface ok you want to be typing in the next hop IP address ok so got that the other way you can write it out is the directly connected statement which actually is shorter and easier to type out so you've got IP route instead of finishing with the next hop IP address you're just going to designate the interface on your router that you are going to exit when that can get I guess slightly confusing because in this statement or this command you are going to be using the exit interface on your router okay versus the next hop IP which is the IP address on the router bits the next hop so interface is going to be on your own device of course next hop IP is the IP of the other device that is your next hop so remember to keep those things separate you don't want to try to type in the interface on the next hop device or the the IP addresses the interface on your own router you don't want to reverse those two essentially so it's always the interface on your own device next hop is the IP address on the device you're communicating with to get to the desired network okay a fully specified route you've got no example of it here um so it's fully specified reality is not going to look like this this is just another example of a static route or a directly connected route static route connected or directly connected static route all they have is the interface out here okay if you were going to have a fully specified route you would have this interface s0 0 zero space then the next hop IP also out there so that would be your fully specified static I don't know why they don't show us that here in the slideshow but just use your imagination and you can picture an IP address being out here it's magical so just put the next hop IP address right after the exit interface as you create your fully specified static route how do we verify those static routes you can do a show IP route static or just a show IP route should be fine too it'll bring up your routing table and you'll be able to see those static entries which you have created all right you could do a show running config as well show IP route for a specific network okay so our interface it looks like so you've got those three commands I just say use a show IP route in general unless your routing tables huge I guess you could limit it to static or connect it or whatever a limiter you'd like okay but those commands will all be useful we'll be using the those in class your default static route the route that catches anything that is not in the routing table that is the quad zero quad zero route so instead of typing in IP route and then some network you're trying to get to this is for anything that doesn't show up in your routing table you've got this quad zero space quad zero route that basically is a route to the gateway of last resort provides a way for you to a direction for you to send traffic that's not in your routing table and it's the exact same situation you can either have a next top route a directly connected route or a fully specified route and create your IP route so in this example they've used the next hop they've used the next hop IP so you can hop that moving right along I'm just remembering some comments in class about sound effects that makes during this video I've been making them try to stop anyhow let's see what else verify a static route again you got IP route static same thing we've seen gateway of blast restore you can see that quad zero you see the Gateway of last resort set up based on that default route so those are things you'll see if your default route is set up correctly and then we have the ipv6 route command ipv6 route command same thing same exact thing there's my two sound effects if I'm in a row there's ipv6 route type in the network you're trying to get to and then you can either use the next hop IP address or the eggs interface same rules same rules as ipv4 again same as ipv4 here and here's a next hop you just have what you're trying to get to slash whatever the prefix is and then you have the next hop IP in this example directly connected using the interface just like ipv4 so fully specified static ipv6 routes you are going to need to use a fully specified ipv6 route if you decide to use link local addresses as your next hop IP because for example we've got our one here who's trying to specify a next hop IP of fe80 : : - over here alright so if your next hop IP is FB ad : : - over here it that might not be useful to your router because each network on your router could have a potentially either a fe80 colon colon 2 on it these link local addresses are only unique on their specific network so these two are only unique to the network that connects them they could have for instance r2 off to the right could also have an fe80 colon colon 2 over here as this link local could have a FB ad cornholio on the bottom at the 82 colon colon 2 at the top you could have multiple interfaces with fe80 colon colon 2 on it our one could be connected to multiple routers that have fe80 colon colon 2 as their link local interface that is connected to our one so let's say that there's a router out here who's also using fe80 : : to our one doesn't know where to send this traffic that matches the network here because there's two links that are connected to FB ad : : - alright so if you're going to use a link local address you need to specify the interface that you're exiting out of here so s zero zero zero in this situation that way you know okay it's going out at zero zero zero it set it for FB ad : : - so it knows exactly where it's going alright in which case you almost might want to just use the s zero zero zero instead of instead of just the link local address there is a reason to use fully specified routes we've just stated that before and we'll talk about that in just a second but not just yet verifying ipv6 route same thing I show ipv6 route show at the v6 route static same things we saw for ipv4 okay default ipv6 route just like ipv4 you had all zeros all zeros and ipv6 is : : that represents all zeros as your ipv6 address slash zero zero prefix so that covers every address just like the quad zero quad zero network in ipv4 and an example of how that set up ipv6 : : zero and then in this example they use the next hop IP using the global unicast address not the link local so they didn't have to fully specify the route okay remember if you're going to use link local you can have to fully specify before we take a look at this slide I'm going to go back a little bit to look at our next hop static route and why that is not the best technique to use there we go there it is so your next hop static route I refer to something called a recursive lookup that I thought came up later on slides but it doesn't so let's talk about it right now if you're going to configure a static route with the next hop IP address that's fine it works but your router is going to have to do a little bit more processing to use this next hop route reason being is you're telling the router that the next hop is this but the router still needs to look in at the routing table as to which interface it needs to use to get to this next hop IP address okay whereas and that's that's what's referred to as a recursive lookup looking up this next hop IP address in order to excuse me in order to send traffic to this network okay so it has to look this up that's called the recursive lookup that next hop you won't need to do that with a directly connected route okay you've just got the interface and it's going to go ahead and send it out of there no lookup necessary so not only is it easier to type in because just less numbers letters to type it also causes it's easier on your router ok it's going to result in faster processing all right now you also will need this direct this fully specified route you might ask why would you ever use a spoke fully specified route if the interface is enough but there are situations where you may have multiple devices at the end of a port ok so it might not just be one device on the end of a port so if you have multiple devices you are going to have to include both the I've shredded Nats at end of a port the end of an interface let's use the correct terminology the end of the interface like the cereal or gigabit ethernet interface so if you have that situation arise where you have multiple devices at the end of interface then you would have to use the interface ID as well as the next hop IP and use that split fully specified route that we discussed earlier where you would type in the interface and the next hop only if only if you have multiple devices at the end of that inner face okay but most of the time I mean in normal person normal in most situations the directly connected route is going to be well and good enough verify ipv6 ipv6 route static floating static routes floating static routes so we need to discuss this quickly before but a floating static route is a backup route you're going to set up these backup routes just in case the desired route or the better route goes down so the example we had before is that you've got this LAN here it's quicker the better route to go but perhaps serial 0/0 this link goes down okay something's wrong with your connection here you also can configure a backup route which is a floating static route that will kick in just in case this link goes down okay to create that you need to create a route with a higher administrative distance than a normal static route and that's easy to do very easy basically or if you remember from chapter one a normal static route has an administrative distance of one one is a very low as the the most trustworthy administrative distance other than a directly connected route which is zero okay so if you configure your routing statement with an extra number at the end same routing statements over here we've got for instance these are both default routes one's going this direction up here which is going to be our desired default route okay but we have another one down here that we potentially could take and in this example we're assuming that this link is slower or less desirable than that one okay so our first routing statement here says send everything from this network that needs to get off the network this direction okay but in case this link fails we've got a backup route here with a zero zero zero zero zero zero zero it's going to set it this direction to the ten ten ten to network this extra five at the end means I want to make the administrative distance of this route five which is higher than the one that would be automatically assigned to our first entry here which means this five will not be used ever if this link is up okay because this is our desired route but in case it goes down you're going to use this link down here and you can make it a five if you want to make it a backup route for something like e IG RP you can make it on ninety five cents a IG RP is ninety so you've got some options there as to how great of an administrative distance you want to give to your floating static route fleet to test the floating static route you can verify that it's there in the routing table with a show IP route if you do a trace route command you can see the path that the traffic the traffic is flowing and if you want to test that floating static route you're basically going to disable the link for your primary route and see if the floating static route kicks in and it should it should if you configured it correctly go ahead and use that backup route if you shut down the link for the primary route here we have the concept of automatically installed routes on a host we discussed those last chapters well they are indicated with the L your local routes that come up when you give an IP address to an interface on your device so those will automatically be entered as as soon as that the interface has an address that hosts route is just for one host it's not for a network okay so every one of your bits are going to be host bits or I should say whoops why did that events why are we moving I don't know or actually the the converse of that pretty much because you you indicate a host route that for one host with a either 32-bit subnet mask or 128-bit prefix or mask in ipv6 which means there's no room there's no network it's fully specified a all 32 bits or 128 bits indicate that one host okay so that's what you're going to see a slash 32 on your elves or a slash 128 on your L entries in your routing table for those links okay because it's indicating one host okay one host address automatically installs we already talked about indicated with the elbe you can actually use those host addresses to set up static routes which we'll see in the next couple slides okay so if you wanted in this situation there using ipv6 you could use ipv4 as well do they have a ipv4 entry here also it doesn't look like yes yes they do alright cool so you've got branch here going to the server alright so if you want to set up a a host route that only communicates with the server servers on a network we've got a 64 bit prefix there you've got a 27 27 bit cider notation there okay so it is on a network this server but we're saying the branch doesn't have doesn't any have any need to communicate with a network in general it just wants to communicate with the server and have a entry in its routing table as to how to communicate with the server only so you're going to use that servers local address okay the L address assigned to the interface on your server okay what you're going to do to make that happen you can see it's server's address is here exactly dot 99 and then you've got the ipv4 addresses up to 3/8 so for your ipv4 statement you're going to type in 209 once the five two hundred two thirty-eight okay as you normally would but instead of indicating the network that it's on with the subnet mask that would match a slash twenty seven you're just going to make that a slash 32 with a 255.255.255.0 five five okay that means this address is unique there's no other room in that network it's just one address okay so this routes going to this address only because you have that slash 32 then you have your normal next hop IP address which is going to be the IP address of your next hop device here okay and really that is about it that is about it so that's what you have for the ipv4 ipv6 same situation you've got the ipv6 address that you're going to write in here that matches this one and you have a slash 128 which means this u address is unique it's not a network that has any other addresses in it okay it's just got this one one entry and again they're using the next hop IP here of the router so it's the same type of static entry you're just using a different prefix length you're using a different subnet mask that contains well all Network bits for the most part and it is all Network bits which means this is the only address available okay you can't communicate with the 27 network in general can't communicate with this / 64 network in general only these interfaces only these addresses are going to be able to be communicated with in your routing table so you can see how that shows up in your routing table down here you've got your static route that we created okay and how you get there and down here you have the same thing static route we created and how you get there okay [Music] so that's configuring a hosts route and there's how you do it with a link-local remember with a link-local address you do need to use the exit interface and the link local address okay and we have our last section here which is actually pretty dang short so troubleshooting default static and default routes same thing we've seen for other triple shooting exercises you're going to use your ping is your trace route to see where issues are taking place ping is good it'll show you if you have communication but a traceroute is going to tell you exactly where the communication broke down or tracer T on a host device so is it worth it the ping I guess but if it fails you have to do a trace route anyway most likely or trace vertie Archie I should say or trace and whatever how we want to call it to figure out which routers down or where the issue is taking place so maybe do a trace route from the beginning okay incorrect route statements can cause problems conflicting routes in the routing table so we'll see a couple of those things in the lab then we have the chapter summary down here and we didn't talk about route summarization now did we I guess we can go back and do that now I'm going to back up a little bit and then well we'll do a quick exercise on route summarization I don't even dig it comes up in this chapters test but it's something we should know ok so here we have this summary route it turns out looks like you won't have to do any route summarization in this chapter as far as testing and labs go but it is useful to know how it's done so this summary route that encompasses all of these routes ok how is that calculated you're basically doing an ending process and figuring out what the network address and subnet mask are for the summary okay so we have a slash 16 that means that we have all of our bits turned on in the third octet here that's the octet we would be working in to figure out our summary address here's how you do it ending process it's going to bring up our chart here and here it is okay so we have these four networks on the slide all right we need to figure out well you know figure out what the summary route is for those the instructions that used to be in the readings which doesn't look like they're in the readings anymore we tell you to take these at all break this entire dress ball four of these addresses down into binary and compare them and contrast them and get your answer but we don't need to do that you don't need to do that what all you're going to need to do to create a summary of route is take your highest entry in your range and your lowest entry compare the bits of the octet on that you're working in in this case the third and you'll be able to figure out your summary route so for instance here we've got twenty as the top twenty three is the bottom okay so what do we do to get a twenty we go zero there zero zero okay 20-16 works so we put a one there leaves us with four at a zero 4 minus 4 0 yeah okay so you got that then we go down to 23 that under the 23 it's going to be basically the same thing zero zero zero and we go to one here that leaves us with seven right so no yes yes yes all right so that's the top entry here and the bottom entry here the third octet in binary that 20 23 in binary okay so where do they match they match all the way up to this point here so they match all the way through there all right do not match here I'm gonna shrink those down there I hope that makes it clear so what we're going to do is compare these okay if we do compare these we see that well you're going to end up with exactly twenty zero zero zero one zero one zero zero all the rest would be zeros over here so the address we're going to start out with is 172 dot 2000 okay that's going to be the network that we summarized but what is the subnet mask well we just have to ask ourselves how many of these bits match okay one two three four five six all right that's six plus the eight in this octet here that all match is going to be 14 so this would be a / 14 address so I don't know where that second period came from probably because I typed it by accident there we go so our summary address is 172 2000 / 14 okay our block size there is going to be 4 all right so that's 0 to 23 that's exactly correct block size so that's exactly what we want to summarize those addresses so if we take a look that should be exactly what they got yes 120 72 20 0.0 / 14 so you're going to compare those bits top and bottom address or highest and lowest address how many match you can use that to your Sider notation your subnet mask and that's going to be how you summarize addresses okay um that's not in your again denying your test but something you probably want to know how to do is summarize I don't think it looking at the materials doesn't look like it's in CCNA - anymore that we use do any summarization on our own but that's how you would do it okay so that's going to be it until next chapter where we start dynamic routing

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Keywords: ccna, ccent, cisco, ccna 2, static, routing, network, academy

Id: GSP6gd1173g

Length: 44min 28sec (2668 seconds)

Published: Sun Apr 09 2017