EIGRP Troubleshooting


You are the senior network engineer for a global company and responsible for the routing of the network. You have worked very hard to improve the network, helpdesk calls have been brought back to a minimum and the network is at peak performance. Your boss wanted to reward you for your excellent input and pays for your holiday, meanwhile the other network engineers took over support. You just got back at the job after your excellent holiday and your mailbox has exploded with trouble tickets! Time to throw the flower necklace in the corner and get back to business!


  • All IP addresses have been preconfigured for you as following:
    192.168.XY.X /24 where X = router1 and Y = router2.
    for example: between router5 and router8.
  • Every router has 1 or 2 loopback interfaces as following:
    Loopback0: x.x.x.x /24 for example: for router1.
    Loopback1: xx.xx.xx.xx /24 for example: for router1.
  • EIGRP is preconfigured with the AS numbers as specified in the topology picture.
  • Do not use show run! (this will spoil the fun ๐Ÿ™‚ use the appropiate ‘show’ and ‘debug’ commands. This will teach you the skills needed to become a true troubleshooting master.
  • One of your colleagues created the frame-relay connection for a new branch office. The branch office is using R3 and the frame-relay switch configuration seems to be ok. No problems are reported between R1 and R2. Since the network engineer at the branch office is out of town you only have access to R1 to solve the problem.
  • After solving the problem between R1 and R3 some of the users on the network are complaining they are unable to connect to a server located on You look on R1 and see the route in the routing table. You are unable to make changes at R2 or R3, but you are able to telnet into R2 from R1 and use the โ€˜show ip routeโ€™ command. The telnet password is โ€˜branch2โ€™.
  • One of the junior network engineers added R5 recently to the network but for some reason the neighbor adjacency with R1 and R5 isnโ€™t working. R1 and R5 are working fine however. See if you can solve the problem.
  • Somebody of the other routing-team decided to redistribute between the RIP network and EIGRP on R4. When you look at R1 you donโ€™t see any entries though, you need to fix the problem on R4.
  • After you fixed the redistribution on R4 you can see the network in the routing table of R1. For some reason you still donโ€™t see it in R5, up to you to solve the problem.
  • Yesterday night R6 crashed and was replaced by your overworked/stressed out colleague. There was no backup of the running-config so he created a new config. Users from the network are complaining that they are unable to reach the network. Your colleague is not here at the moment so you need to fix the problem.
  • The network engineer from R7 also experienced problems with R6 and got impatient. He made some changes to R7 to solve the problem but now thereโ€™s no connectivity at all with R6โ€ฆhe has no idea how to fix it so you need to help him out.
  • One of the new trainees in the network team added a network command on R1 to advertise the network. When you look on R2 or R3 you donโ€™t see this network in the routing table, you need to help him out. You are only allowed to make changes on R1.
  • Some of the users are complaining in AS 467. Computers located in the network are unable to communicate with the network. You test if this is true by sending a ping from R6 towards the network and using the loopback1 interface as the source and confirm the problem. See if you can fix it.
  • Between R5 and R8 there should be an EIGRP neighbor adjacency but something seems to be wrong. The security team made some changes yesterday but they claim everything went ok.
  • R8 has been configured to redistribute RIP into EIGRP AS58. However, for some reason you donโ€™t see the network in the routing table in R5 which is also in AS58. R8 is an older router and you want to make sure it doesnโ€™t get overburdened by queries from R5 looking for lost prefixes.
  • Users in AS145 are supposed to have access to a server located in network Make the appropriate changes on R5 so this is possible.




EIGRP Troubleshooting

Video Solution:

Configuration Files

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Once you are logged in you will find the configuration files right here.

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Written by Renรฉ Molenaar - CCIE #41726

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About the Author: Rene Molenaar

Renรฉ - CCIE #41726 is the creator of GNS3Vault.com where he shares CCNA, CCNP and CCIE R&S labs. He also blogs about networking on http://networklessons.com


  1. A very good lab!
    Came across a lot of new stuff and managed to pull it off ๐Ÿ™‚
    I really appreciate your efforts on this.
    Thanks a bunch

    And can we have labs like these for RIP, OSPF and BGP?

  2. Glad you like it. I got a OSPF and BGP one i’m finishing…should create one for RIP as well.

    They take a lot of time to create because first I need to think of a lab….then configure it and then think about “stuff” to break so you can fix it in a chronological order 8)

    I use these in my troubleshooting courses, most people like them ๐Ÿ™‚

  3. I just completed all 3 of the Ascolta classes, I have all the materials. I’m most interested in the TSHOOT labs. The topology diagrams I have don’t seem to match anything I’ve seen on the web. I would be happy to send all the topo maps, configs, etc. I have everything. This is all for the new CCNP track.

  4. Having just completed the TSHOOT course at Ascolta, I was wondering why all the topology diagrams I see on the net don’t seem to correspond to what I saw in class. I have all the diagrams, configs, books, you name it. I would like to see someone who’s more familiar with GNS3 create the labs exactly as they appear in the books, so I could practice them. Anyone interested?

  5. @Rene

    Regarding the task:

    After solving the problem between R1 and R3 some of the users on the network are complaining they are unable to connect to a server located on You look on R1 and see the route in the routing table. You are unable to make changes at R2 or R3, but you are able to telnet into R2 from R1 and use the โ€˜show ip routeโ€™ command. The telnet password is โ€˜branch2โ€™.

    After issuing the no ip split-horizon eigrp 123 and pseudo broadcast on s0/0, R2 still not learning routes. ;D

  6. When trying to get through the first question, eigrp on R1 keeps erroring “retry limit exceeded” and no joy. Those configs in the pack are the solved ones or the raw?

  7. @Jem

    Do you see anything in debug output why the route is not being installed in the routing table?


    The configs are the “startup-configs” Expect this error and many more nasty errors…it’s a troubleshooting lab after all ๐Ÿ˜‰

    Good luck!

  8. @rene

    Thanks Rene! It took me 2 hours to solve this issue!

    Mar 1 03:05:18.927: IP-EIGRP(Default-IP-Routing-Table:123): – denied by distribute list

    *Mar 1 03:05:19.631: IP-EIGRP(Default-IP-Routing-Table:123): – denied by distribute list

    At first, I issued debug command but nothing happens until issuing clear ip eigrp neighbors and debug output came.

  9. @Nonsense

    My goal is to have a final config + youtube video for every lab on the site…this is gonna take a lot of time, if you look at some of the “OSPF” labs you’ll see an example. For the moment, if you have any questions you can ask them on the forum/comments here and i’ll answer them.


    Nice job…this is exactly the goal of the Troubleshooting labs, using the show/debug commands to pinpoint the problem. Keep in mind it’s not about the end but practice to train your “debug” and troubleshoot skills…keep on going! ๐Ÿ™‚


  10. Hello!
    How to show current values of “metric weights” without “sh run”?

  11. Current values of “metric weights” or K-value show command “sh ip protocols”

  12. Make you wonder the people that run this network are total Muppets, they obviously havent studied with GNSvault, Id Sack them !! Ive met better MCSEs . Ive corrected all the faults now.

    Must admit couldnt stick to the no show run rule!! Im weak… maybe next year !

  13. I can’t figure out why the redistributed rip routes aren’t in r5 topology or routing table… I’ll keep looking however.. :/

  14. Not a bad lab to start with. Drawed from my CCNA days.. esp frame-relay which i dont get alot of time with anyways.

  15. Took a while but finished the entire EIGRP TSHOOT lab. Trying to find out why R5 could not get the address was a real headache but learned the router-id is under the eigrp topology command and the “sh ip eigrp event” command which gave me the answer (almost used sh run). GREAT LAB, I learned a lot and thank you for your hard work when creating these labs.

    1. This was the tough one, could not help myself to no to use show run for EIGRP section. At least I will not forget for future where to look next time.. show ip eigrp topology ๐Ÿ˜‰

      Very nice lab.

  16. Hello Rene.
    After I apply the no-split horizon on s0/0 on R1 I can see the route on R2 like you show in the video, but I can’t ping it, so it is still unreachable. I also did a “show ip route” on R3 and is present but also not pingable. I’m not sure as I can’t see running configs on R2 and R3 but I think they need an extra map statement so they can reach each other.
    Thanks a lot for the new labs and videos.

  17. Hi Allex,

    Check if the next-hop IP address for those prefixes is reachable, it’s probably not. If so check your frame-relay mapping statements because you probably don’t have an entry there for the next-hop IP address. Add it and you should be able to reach the other side.


  18. Hi Rene,

    First i want thank you for this really great site ๐Ÿ™‚
    I have the same problem as Allex1 and cant figure out the fault…

    R1#show ip route is subnetted, 1 subnets
    D [90/2297856] via, 01:03:25, Serial0/0 is subnetted, 1 subnets
    D [90/2297856] via, 01:00:38, Serial0/0

    R2>show ip route is subnetted, 1 subnets
    D [90/2809856] via, 00:16:28, Serial0/0


    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
    Success rate is 100 percent (5/5), round-trip min/avg/max = 16/21/36 ms

    R3>show ip route is subnetted, 1 subnets
    D [90/2809856] via, 00:20:53, Serial0/0


    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
    Success rate is 100 percent (5/5), round-trip min/avg/max = 20/25/36 ms

    Where is my fault? ๐Ÿ™
    Thank you.

  19. Hi Rene,

    Thank you for the really fast answer!

    You assume it right, i can ping the next hop (Router 1) but not the loopback.
    Ping Router 2 -> 3 Loopback and Router 3 -> 2 Loopback isn’t working.

    Problem is, i dont have access to the lab acctually, but maybe the problem is that Router 2 doesn’t know a route to Router 3 source interface. I will check this later ๐Ÿ™‚


  20. Ok, some more Information.
    I can Ping from Router3 with source
    R2#ping source

    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
    Packet sent with a source address of

    If i do a normal ping i see this behaviour:
    *Mar 1 00:04:10.191: ICMP: echo reply sent, src, dst
    *Mar 1 00:04:12.215: ICMP: echo reply sent, src, dst
    *Mar 1 00:04:14.183: ICMP: echo reply sent, src, dst
    *Mar 1 00:04:16.179: ICMP: echo reply sent, src, dst
    *Mar 1 00:04:18.199: ICMP: echo reply sent, src, dst

    So the problem is R1 can’t reach R3 via Framerelay direct (Ping doesnt work. Is this correct??…

    Thanks in advance

  21. Hi Richard,

    In your output I can see that they know about each others loopback networks. You can ping the next hop IP address but you can’t ping the loopbacks? Is that right?

    If your next hops are reachable then your frame-relay mappings are OK.

    Which ping is not working?


  22. Sorry for the tripple post, but i think i figured it out on my own ๐Ÿ˜‰

    There is no Frame-Relay Map on R2 so there is no chance it can reach R3 via in anyway. So a Ping should (and will) only work from to and other way, but never direct from the switch.

    I think i just read the question not good enough ๐Ÿ˜€

    May you can tell me if im right or wrong with my final statement?

  23. Hi Richard,

    I think you got it right. When you are facing problems like this, I always check this in the following order:

    1. Can I reach the network, in your case
    2. If it’s unreachable, I try to reach the next hop for that network.
    3. If the next-hop is unreachable you need to check your frame-relay map and fix it.

    Keep in mind you need to do this on BOTH routers. It’s possible that your router knows how to send traffic but the receiving router doesn’t know where to send it’s IP packets and drops the traffic.

    A good command to test this is “debug ip packet”. Don’t use this on a production network ;D It will show you what the router does with incoming or outgoing IP packets. Best thing to do is to combine “debug ip packet” with an access-list.


  24. Just getting back to TSHOOT study after Xmas break. Great Lab! just what I needed to get back into the Swing of things. Hoping to tackle TSHOOT exam in next 2/3 weeks.OSPF tommorow.
    Top Man

  25. I’m glad you like it! I think you’ll like the OSPF troubleshooting as well, it’s pretty good.

  26. Just finished with this lab which I’m using to prepare for TSHOOT. I really liked this one! Keep up the good work ๐Ÿ™‚

    1. Good job ๐Ÿ™‚ Try the OSPF troubleshooting as well…..i’ll see if I can make one for BGP as well.

  27. Thank you very much, Rene

    I solved all problems except the last one,,,took from me 2 hours..But it was interesting.

    Strong effort.

    Thank you

    1. If you managed to work your way through this by yourself it proves that your EIGRP knowledge is excellent ๐Ÿ™‚ good job!

  28. Excellent lab. I really enjoyed utilizing the show/debug commands which helped me rely less on my skills of reading through config files to make a proper assessment of the network topology.

    The one problem I found the most enjoyable was the R5-R8 EIGRP problem isolation. Key tip *security team….lol….

    Have a great day everyone.


    1. Glad you enjoyed it MJ. This is one of those labs where you really need to use the show/debug commands. Just comparing the configurations doesn’t do the job ๐Ÿ™‚

  29. @ Rene

    Nice work , I really enjoyed and completed the lab. need more Eigrp Labs!!!!he he
    Thanx alot again

  30. This was another awesome lab! I almost gived up not to use sh run! It took me a while but got it solved. I actually found the EIGRP Troubleshoot lab harder than the OSPF one, took me almost 3 hours! :0

    By the way Rene, are you thinking of throwing out a BGP Troubleshooting lab? Im really interested in taking a good BGP practice, plus there are a lot of stuff that can go wrong in BPG ๐Ÿ˜‰

    Thanks for you exelent labs! ๐Ÿ˜‰
    Looking forward to solving another of you cool labs!

  31. @Rene What an awesome lab .. I loved it ,, it really test tshoot skills … i wish you all the best … THANK YOU and keep it up

  32. [quote=fraczekl]I am logged in but I cannot see the topology download link…[/quote]

    nevermind, all is good after I logged off and logged back in…

  33. Pinging from R2 wont be possible since neither R3 nor R3 has got a map to each other. Having a route to being sent to R3 by R1 by turning the splt-horizon off will push the into R3 routing table of course , but those two guys R2 and R3 still need a map to exchange packets with each other.

    Rene mentions in his video solution only the "no split-horizon", but it wont be sufficient a R2-R3 map is needed for R3 to ping R2

    Cheers, MB

  34. This one looks life fun. I think I’ll record a video and post on my YouTube channel. RobRikerCiscoTraining if anyone is interested.

    I’m also going to start going through these labs to find where I’m weak. All the labs look straightforward but you wont know till you do them

  35. This was a difficult but interesting lab. I believe it goes beyond the CCNP to the CCIE level. The only thing that stumped me was the RouterID issue (don’t want to give the solution away). I had to research the possible problems and then it hit me. Made the change and the route propagated. I’m definitely gonna do more labs. Keep em’ coming!

  36. wow, super Challenging lab ๐Ÿ™‚ made it through the end without using the show run command!
    Thank you very much Rene. By the way, i saw your books now available on paper copy!! congratulations.

  37. i am stuck in R5 and R1 .
    resolve the issues uncommon subnet and advertised the correct network but unable to ping R1.
    debug ip packet shows

    *Mar 1 01:33:31.211: IP: s= (FastEthernet0/0), d=, len 60, rcvd 2
    *Mar 1 01:33:31.607: IP: s= (local), d= (Loopback0), len 60, sending broad/multicast
    *Mar 1 01:33:31.611: IP: s= (Loopback0), d=, len 60, rcvd 2
    *Mar 1 01:33:32.023: IP: s= (local), d= (FastEthernet0/0), len 68, sending
    *Mar 1 01:33:32.027: IP: s= (local), d= (FastEthernet0/0), len 68[b], encapsulation failed[/b]

    debug ip eigrp ::::

    *Mar 1 01:43:39.619: IP-EIGRP: – do advertise out FastEthernet0/0
    *Mar 1 01:43:39.619: IP-EIGRP: Int metric 128256 – 256 128000
    *Mar 1 01:43:39.623: IP-EIGRP: – do advertise out FastEthernet0/0
    *Mar 1 01:43:40.227: IP-EIGRP: – do advertise out FastEthernet1/0
    any clue.

  38. Popular TSHOOT lab! this was fun Rene! you really messed up this one for us ๐Ÿ™‚

  39. I downloaded the file and it has the configurations. How can I download the network pre-configured?

  40. Great Lab Rene.

    Just a point that may be silly but… I do not see why R8 is not receiveing any route from eigrp 58.

    In any case, when I remove the ACL, stub config, etc. it is still not receiving any route.


  41. HI Ren, i configured eigrp troubleshooting lab all in one

    it took me 3 hours because k value mismatch gave me a headache
    to over come. Console messages were flooding and i couldn’t just
    get the globle mode.
    i did not take a look students comment wich would help me alot
    to disable the console message
    over all i configured Eigrp neighbour troubleshooting and Eigrp
    all in one troubleshooting lab using my own Ren’s recommended
    way to troubleshoot!!
    thanks Ren all the time


  43. Thanks Rene for the excellent labs.
    I was really having a difficult time understanding why the 3 network was not being learned on router 2 even after I added the "no ip split-horrizon" command. Then I started using the debugs, did a soft reset of the EIGRP neighbors and there it was.
    I really can see how, with your help, I am well on my way to mastering CCNP and beyond!

  44. Hi
    First of all a million thanks to RENE…… for this "headache" lab …
    which is very helpful .for leaning eigrp , by brain storming ……..

    I fully agree with Renee and also suggest not to use "show run" command …
    I took me while to solve { never used show run } ….but it was fun

  45. You can see the duplicate router-id in the following command.

    show ip eigrp events.

    This is generally used for Cisco TAC and is a hidden command.

    It is very useful, use it and see what is going on. It tells you about a duplicate router-id in there…

    1. Hey buddy, I am unable to load this topology in GNS3, any issues with this topology currently?

  46. @ Zafar which IOS Version ur GNS3 is running on? it should be ios 3640….

  47. Hi Rene, This was an awesome challenge ๐Ÿ™‚ really a pretty crazy config messup… I did enjoy my time spent troubleshooting this lab ๐Ÿ™‚ to success ….
    Thanks so much for your work ๐Ÿ™‚

  48. Hi,
    excellent lab, very hard and tought as supposeto be, nice work
    Thanks so much

  49. Great lab I aced it!

    Nice warm up lab got my CCNP TSHOOT on Saturday currently working through your book which is excellent. Keep up the good work and thanks for all the effort!

  50. Hi Rene,

    I’ve downloaded the startup config but I cannot see a topology file, I can see a file called eigrp-troubleshooting-startup-configs.gns3 but its not loading into GNS3 properly, am I missing something?


    1. Ah see you updated all lab topologies I see this must be the issue, will try updating my GNS3 thanks!

  51. Hi Rene,

    Thanks so much for this lab. Its such a good one. It was a lil hard at first doing without “show run” but I scaled through anyways. Really tough one.
    Thanks also for all the lab files for old version of GNS you sent to me. Really rocking my labs with it without going thru d headache and hassles of resolving the errors in new version.
    I’ll have 2 wait a little until the new version is very stable before installing.

    Thanks Rene.

  52. After troubleshooting my routing table was fine in R2 but I am not abe to ping but why

  53. Great lab! The part with the user-id was a doozy. I hope the TSHOOT exam creators aren’t as ruthless as you are. :p

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