One-Way Redistribution


Your local neighborhood pet shop has asked you to help them solve some network problems. The pet shop is running OSPF and recently bought another shop that is running EIGRP. To achieve connectivity they use redistribution but now some users are complaining about the slow network speed. Up to you to fix some problems!


  • All IP addresses have been preconfigured for you.
  • Configure OSPF on router Ace and Aggie and only advertise network /24.
  • Configure EIGRP AS 1 on router Ace, Aggie and Abu. Only advertise network /24 and /24.
  • Redistribute the loopback0 interface in EIGRP AS 1 on router Abu.
  • Redistribute EIGRP information into OSPF on router Ace.
  • Do a traceroute from router Aggi or Ace to network /24. You notice that you are not using the most optimal path…fix this problem so router Aggie uses the most optimal path.

It took me 1000s of hours reading books and doing labs, making mistakes over and over again until I mastered all the routing protocols for CCNP.

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You will learn all the secrets about redistribution between OSPF and EIGRP, sub-optimal routing and more.

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One Way Multipoint Redistribution

Video Solution:

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Written by René Molenaar - CCIE #41726

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About the Author: Rene Molenaar

René - CCIE #41726 is the creator of where he shares CCNA, CCNP and CCIE R&S labs. He also blogs about networking on


  1. Super lab. 3 ways to solve it like the multipoint one way scenario you can use distribute lists, tagging or alter the distance.

    1. Glad you like it. This is one of the labs that is very helpful to understand the issues that redistribution might cause.

  2. I used access list 1 deny in router ACE
    then applied on ospf DISTRIBUTE-LIST 1 out

    but it’s good thank you 🙂

    1. That’ll work, don’t forget to add a ‘permit any’ though or everything will be blocked by the implicit deny any at the bottom of the access-list.

  3. in video, you DO NOT need to type metric when redistribute connected in eigrp. It will work fine without it, thoug its not a mistake.

    1. Thanks for sharing this. I didn’t realize this but you are correct. Redistributing the directly connected interfaces doesn’t require a seed metric, only from other routing protocols.

  4. This Lab is excellent. I really learnt the redistribution concept. Thanks Rene.


  5. I always had trouble with Access list and different ways to use it. Could you please upload a dedicate lab for teaching access list concepts in detail.

  6. plz i do have a question
    i tried instead od increasing the AD of OSPF external routes
    i increased the AD of EIGRP to 180. and decreased the AD of OSPF external to 100
    on Router Ace it didn’t work but it worked in router Aggie
    i disabled Split horizon and now Router Ace can see it through router Aggie but can’t ping it
    my question is, why it sees it going to the interface of Router Aggie not directly to Abu
    and why its not pinging knowing that even Aggie is pining

    [color=red]Personally i believe that it needs a way of connection between the redistributed eigrp and network because when i tried to ping with source interface f1/0 with ip, it failed but a normal ping works[/color]

    here is my output for Ace

    Ace(config-router)#do sir
    Codes: C – connected, S – static, R – RIP, M – mobile, B – BGP
    D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
    N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
    E1 – OSPF external type 1, E2 – OSPF external type 2
    i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
    ia – IS-IS inter area, * – candidate default, U – per-user static route
    o – ODR, P – periodic downloaded static route

    Gateway of last resort is not set

    C is directly connected, FastEthernet1/0
    C is directly connected, FastEthernet0/0 is subnetted, 1 subnets
    O E2 [100/20] via, 00:02:35, FastEthernet1/0
    D [90/30720] via, 00:09:09, FastEthernet0/0
    Ace(config-router)#do ping

    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
    Success rate is 0 percent (0/5)
    Ace(config-router)#do trace

    Type escape sequence to abort.
    Tracing the route to

    1 16 msec 28 msec 16 msec
    2 * * *
    3 * * *
    4 * * *
    5 * * *
    6 * * *
    7 * * *
    8 * * *

    1. i solved by adding another distributing OSPF under EIGRP in both Aggie and Ace, but if there is any other way plz let me know

  7. Hello Rene !

    I have a question about this lab.

    After done, i tried to shut the Abu f1/0 interface and ping from Aggie but the ping not working, Why ? Abu have a route to Ace and Ace have a route to Abu where is my mistake ?

    1. hello, I guess since we have single point redistribution, router abu doesn’t have any knowledge about the route If we shut down the port f1/0 in router abu, the reply for the ping request from aggies to network should be returned via network and check the routing table of abu you cannot find 12.0 entry. Now turn on the f1/0 port and you can see aggies select the route (the EIGRP route) to Router abu knows the network 23.0 and the reply should be sent via 23.0 link.

  8. enter your message here…[quote=ReneMolenaar]That’ll work, don’t forget to add a ‘permit any’ though or everything will be blocked by the implicit deny any at the bottom of the access-list.[/quote]

    hi rene,i tried your advise about to add a ‘permit any’ at access list,but still uses ospf route in aggie..but when i get rid of ‘permit any’ at the access-list, on aggie then uses the eigrp route going to is that..??

  9. Hi guys, quick question. Why don’t we add the Abu’s loopback int in the EIGRP config?
    I wasn’t seeing the external routes, then I removed the loopback network from EIgrp config and it worked?

  10. Also is there a nice explanation that breaks down redistribution on this site?

    Thanks for your help!


  11. Dear Rene,

    This is waqar I already downloaded your CCNP books.If you have plan or you are in middle of writihng CCIEv5 book kinly let me know.


  12. Great lab,!! there are many ways to solved this!

    I used the distance ospf extenal 190 on router Ace and Aggie ( thus changing the AD in extenal ospf to 190.

    I also used a route-map set a next-hop 🙂 method 2 …

    It was fun.

    Thanks Rene.

  13. Hi Rene,
    Thanks a million for this lab.
    Please i have a question. in the video, why are you not able to ping except when you source it from the f0/0 interface?

  14. Possible ways to accomplish this lab:

    1) Change administrative distance in EIGRP on Aggie to have external routes with a lower AD than 110…OR change AD in OSPF so that the type 5/7 LSAs get a AD of > 170. Changing AD isn’t always recommended, as it introduces chances of blackholing (what AD is trying to prevent).

    2) Distribution list on Aggie (not scalable) to block the LSA from being put in the routing table.

  15. I simply put a static route on Aggie to reach through it’s f0/0 interface, which gives the default AD of 1.

    But then I was worried that Aggie would advertise this static route to Ace (which would have an AD of 1 for the static) and cause Ace to use the wrong path to get to, but Ace kept its path going straight to Abu. I’m guessing this is because my static route wasn’t being redistributed into OSPF.

    So yeah, unless there’s a danger I missed, I think I chose the simplest solution.

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