Hi, welcome to this CertificationKits CCNA training video on EIGRP configuration.  EIGRP is Enhanced Interior Gateway Routing Protocol, a Cisco proprietary protocol, meaning it will work on Cisco routers but nothing else.  We’re going to be covering the CCNA exam configuration commands and show commands so we can see what we’ve actually configured as well as some trouble shooting of EIGRP.

Here is the diagram that we’re going to be configuring. Actually the diagram is configured.  This represents the router set up that we’re going to be configuring. The autonomous system number is something we’re going to have to agree upon for all of the routers and like all the other times we’re going to use the autonomous system number, 100.  Again it doesn’t have to be100, it can be anything between 1 and 65,535. If you’re on a public domain like the internet, we would have to get one assigned to you.  We’ve got three routers palaestra1, palaestra2 and palaestra3.  These subnets are configured against the routers. We’ve configured the IP address and the subnet mask on each interface.  So the routing tables look like this. Every directly connected subnet is in the routing table right now.  What we’re going to do is, we’re going to going and enable EIGRP to get these routers talking to each other.

Remember they’ll establish neighbour relationships, they are filling they’re topology tables and then they will take their successor rouet out of the topology table and put it into the routing table.  So we’re going to go in and take a look at configuring this right now in the CCNA simulator.  So, in the CCNA simulator, I have everything configured just like we show on the CCNA slide. The only thing that’s not configured is EIGRP. So we’re going to go in and do that right now.  It’s not a bad idea, before I configure EIGRP to make sure that my interfaces are up.  I can do show interface and I can see Ethernet0 is up, Serial0 is up.  If I do a show IP route command, I can go in and see that the .32 subnet and .8 subnet are added to the routing table and the interfaces are up, everything looks good. Now we’ll go in and enable EIGRP.  I must go into global mode again configure terminal or config t if you’re lazy like I am.

Now we type router EIGRP and then it wants the autonomous system number.  Again every router with the same autonomous system number that’s going to be directly connected will share in EIGRP information. So this autonomous system number is globally significant.  Meaning it’s got a match on each of the routers if I want it to work.  Now we have the network command and I specify the network address.  This allows me to put all interfaces that start with the 99 in network or in the router EIGRP autonomous system number of 100.  So every interface of this router that starts with a 99 EIGRP will route for that particular subnet and I have got two interfaces on this router on both of them start with the 99.  So, I can go network 99 enter, I just published the network in EIGRP.  That’s all I have to do at this moment so.

Let’s go in and configure palaestra1. I’m sorry palaestra2 and palaestra3.  I will go up here select palaestra2, same thing.  Show IP route, check out the routing table everything looks good and its telling me the interfaces are up because this directly connected subnets are showing up in the routing table.  Global mode router I can type, EIGRP 100 again. 100 is the autonomous system number it’s got a match network, what do all they have – all the interfaces have in common, 99.  And I am done with palaestra2, we’ll go to the last router palaestra3.  Router EIGRP 100 network now all three routers are configured. Let’s take a look at palaestra1 right here and see our routing table show IP route. Now I see five subnets in the routing table whereas before I only saw two.

These are the three that I learned through EIGRP.  These are no directly connected subnets.  Let’s take a look at this. D stands for if I look up here if I ever forget I can just look right here, so IP route, right up the top little decoder, so you don’t have to bring your decoder in with you, it’s got one right here.  D EIGRP that’s the destination subnet. 90 is the administrative distance. Now again the administrative distance is used when there are multiple paths to the same destination, but different protocols have found that path.  So if I had a RIP path to 99.40 and – and EIGRP path to 99.40. The RIP path will lose out and I take the EIGRP path regardless of which one was faster.  And yes you can have multiple routing protocols running on one router.  Here’s the cost, EIGRP uses a multiplier to figure out the cost based of the bandwidth and delay on the interface by default.  So, bandwidth and delay by default.

Next hop router that I got the update from that had that information for that came in through the Serial0 interfaces.  So, it shows me all that information let me take a look at some of my show commands here show IP protocol.  If for some reason my routing table’s not showing up or things aren’t showing in routing table, I want to check out and see that I have a protocol running and verify the autonomous system number and make sure it matches.  I’d also go in here and check routing for networks Make sure it's routing for right network. if I accidently typed and there aren’t any interface that start with the 98 on my router; then it wouldn’t be routing for anything. 

Here’s the next hop routers, and the administrative distance, external EIGRP is a path or an EIGRP route from a different autonomous system so external means outside of our autonomous system.  So if you have to go outside of the autonomous system, the administrative distance will be a higher number. Let’s take a look at a couple of other show commands here.  The show interface command again is something that I would check if I'm troubleshooting make sure it's up and up.  Again this is layer one, this is layer two and it also check the layer three IP information to make sure it’s correct if my routing table is not populating.  So on Serial0 here I have  So what I would do is I would do show CDP neighbours detail and I would check out the detailed information here. His IP address for palaestra2 is that’s an appropriate  IP address and I would also verify that I could ping

If I can’t ping the next hop router then there’s probably going to be a problem. When need to get my routing table populated since they can’t communicate with each other.  If I can ping everything is good and then I will go in and check out the EIGRP configuration more closely.  I love show run for that.  I can use show IP protocols as well but show run works great. I just look right here; router EIGRP 100 network 99 and pay attention to these numbers. If they are not correct on both routers they are not going to communicate.  There are some EIGRP specific commands we can look at like show IP route if we had a huge routing table. I could just do EIGRP.  I can do show IP EIGRP topology and I can see my topology table.  CCNA simulators are not a 100% accurate on the topology table as it shows every subnet in here as directly connected. But it gives me an idea of what the topology table looks like.  Other commands I can do are show IP EIGRP neighbours and again I would want to make sure that the appropriate neighbours are in here and if they’re not in here that tells me that it's not able to establish the neighbour relationship for whatever reason; autonomous system number, IPs whatever and that’s why the routing table is not populated and so the routing table is now populated and I can ping I am going to go in here and verify the neighbour table next.

I have brought up this network map because I have gone in and introduced some problems between palaestra1 and palaestra2. So they’re not populating each other’s routing tables.  PC1 cannot ping PC2.  So we’re going to go in and figure out why PC1 can't ping PC2.  PC2’s IP address is and we get a request timed out.  So we’re the CCNA administrators and we’re going to go in and start taking a look at the palaestra1 router and figure out what the heck is going on and why there is no connectivity.  The first thing we want to do is show IP route just to check it out. But I don’t know what that command does.  Show IP route checks it out and see what's in there. is the only subnet going on in the routing table right now so what that's telling me is I know there is a Serial0 interface.  I am thinking it must be down. 

So, what I am going to do is I am going to type in show interface and I will look at the status of the Serial0 interface. It says it is up; that’s layer one, Line protocol is down is layer two of the OSI model.  So, let’s see if we can figure out why this line protocol is down.  With this layer two being down, there is no way the EIRGP is going to be able to function and establish neighbour relationships so we have got to fix this first and see if that allows EIGRP to do its thing.  If I do a show run I can go in and take a look at the configuration real quick and I am looking in here and I know the interface Serial0 is this side of this back to back link between palaestra1 and palaestra2 that handles the clocking and there is no clock rate command now.

So what I’m going to have to do is I’m going to have to specify the clock rate. Again your should know for your CCNA exam that clock rate sets up the timing for the link in a back to back environment.  So I’m going to go into the interface and type in clock rate 64000 and see if that brings the interface up.  Show interface Serial0, line protocol is still down. So if I set the clock rate and the line protocol is still down, there is only one other thing it can be and that is the layer two encapsulation.  Right here it says encapsulation is HDLC. That’s Cisco’s default layer two encapsulation. Again I’m talking about layer two of the OSI model.  Both sides of the link must match, so let me go over to palaestra2 and look at its layer two encapsulation.  I look at layer – palaestra2 and I see here it says encapsulation PPP Point to Point Protocol. That is a multi vendor layer two encapsulation.  They don’t match. They must match so I’m going to go in and go to interface Serial0 and type encapsulation HDLC.

And I’ll do a show interface Serial0 over here and I can see that the line protocol is now up so layer one and layer two is up and functioning. Let’s go back to palaestra1 and check it out from there.  Show interface Serial0, layer one layer two good, now we need to check the IP addressing.  We’ll do a quick look here show run I can see the address looks right. Let’s see if I can ping the next hop router; ping, this is where a good documentation would come in handy. Making sure I had all the appropriate IP addresses documented and I was looking at the documentation when I am troubleshooting this.  So I get a ping now see if EIGRP is populating; show IP route is still not populating.  So more than likely now it's a problem with EIGRP. We’ll do a show run again.  And I look here and I see router EIGRP and the autonomous system number is 101. But check the autonomous system number on palaestra2 with a different command; show IP protocol and here I see EIGRP is 100. So on palaestra1 the wrong autonomous system number is there.  So if I forget the command to go in and change the autonomous system number. All I have to do is look at the running config.  I go into global mode that says router EIGRP 101. So I will go no router EIGRP 101, and I’ll type router EIGRP 100 enter. Then here is my network command, network and one other thing to look for again at those IPs. That says 98 all my IPs on my router starts with 99 so I will go on

I've basically gone through all the stuff so it takes a reconfigure in the first place.  And now if I do a showIP route, I can see that my routing table is populated and I’ve through and successfully done some troubleshooting on EIGRP. Scroll really far and here it is again; D EIGRP, next hop routers, I’ve got all the subnets that are not directly connected to my routing table; so it looks good.  Now the last thing is to make sure that palastra1 can ping palaestra2.  Ping success; everybody is happy.

Let’s go in and do a little recap of the CCNA level commands for EIGRP. We have got router EIGRP, then the autonomous system number, remember that has the match.  I’m not intentionally drawing the line through it, let’s get rid of that.  So the autonomous system number remembers that thing’s got a match. If it doesn’t match on the routers that you want to talk to, they are not going to make friends in exchange topology information.  Network, then the network number we were using a network number of not a subnet.  On the most recent IOS versions with Cisco you can actually specify a subnet in a wild card mask.  Its not available on all routers.  Maximum paths and then the number of paths so if I go router EIGRP 100, and then specify my network, I can use the maximum paths, max paths I’m just put max as I have been lazy.  One, and that will disable load balancing, so that command works with EIGRP, variance, and then the multiplier just like with IGRP I can put a multiplier here.  So if I did a variance of two, whatever my best cost path was and any other path up to two times as bad as that would go in the routing table and I would load balance.  Traffic share balanced that would actually load balance if I had more than one equal cost path in the routing table and then minimum would use the best cost path would immediately use any additional path that met the variance condition if the best cost path went down.

Again it just slows down the amount of time it takes for a convergence or speeds up the amount of time it takes for a convergence; faster is better.  Passive interface and then specify the interface like in our situation Ethernet0.  If we are looking at the router there was nothing over there. Just some computers, actually just one computer.  There wasn’t a router over there that would be establishing any neighbour relationships.  So since this guy is not a router.  I would have the passive interface E0 command and they would prevent palaestra1 from trying to establish friends or neighbours on Ethernet0.  So, some important commands with configuring EIGRP and not only is it important to remember the configuration commands but the show commands as well.  Show IP route allows us to check out our routing table.  If it’s EIGRP we’re going to see some Ds in there.  Again if you forget it, it’s right at the top it will tell you what D means.  Show IP protocol allows me to check out my EIGRP Configuration.  This allows me to look at my neighbour table, neighbours are good if there aren’t any neighbours in there then my topology table won't be populated.

Topology will show me my successor route which is the best cost path that’s the good one and the feasible successor path which is basically a backup.  It will not show me the entire topology of the network. Remembers only the successor and feasible successor is going to the topology table.  The successor route also goes into the routing table.  Show IP route EIGRP will allow me to view only EIGRP routes if I had a very large routing table which is possible.  And show IP EIGRP traffic, this will list traffic statistics about EIGRP. So I can see how much information EIGRP is sending out list traffic stats.  So some very helpful show commands with EIGRP so we can go in troubleshoot figure out what's going on.  So with EIGRP configuration we have gone in looked at the configuration commands configured EIGRP we tested it.  We did some CCNA level troubleshooting utilizing all of our show commands.  Show IP route, show IP protocol, show running config, which I really enjoyed and we did some troubleshooting. Created some problems for EIGRP then went through the steps necessary to resolve them.  Well I hope you have enjoyed this CertificationKits CCNA training video on EIGRP Configuration.