BGP Conditional Advertisement


An international toy store company needs your help. They use BGP to exchange routing information between their sites but everytime one of their IBGP routers fails they have connectivity issues. Let’s see if you can help them out!


  • All IP addresses have been preconfigured for you.
  • Configure EBGP between AS 1 and AS 2.
  • Configure EBGP between AS 2 and AS 3.
  • Configure router Pegasus to advertise network /24 in BGP.
  • Configure router Phoenix to advertise network /24 in BGP.
  • Configure router Pegasus so it does no longer advertise network /24 when network /24 is no longer reachable.




BGP Conditional Advertisement

Video Solution:

Configuration Files

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The How to Master series helps you to understand complex topics like spanning-tree, VLANs, trunks, OSPF, EIGRP, BGP and more.

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. Hello,

    On router pegasus im seeing that both networks are in your diagram

  2. Gday Mate!
    Nice work absolutely wonderful just there is little typo in topology ip address link between Pagasus and Pixie is 192.168.23.x not .12 rest is all good

    I like your name selection thoughts


  3. Hi Rene,
    Thanks….Can you add a video for Performance Routing (PfR) in GNS3..


    1. Hi Bava,

      Will do for sure, it’s still on my to-do list but it’s one of those topics that i’m not too excited about =)



    Nice and wonderful it works nice, i am learining unknown things from this vault. Thanks for your amazing blog..

  5. HI Rene

    I have just had a look at this video and have a following questin.

    You created conditional map which withdraws lo0 when neighbour relationship between pagesus and phenox is manually shutdown. My question is as follows.
    Would bgp not automatically withdraw from its BGP routing table and stop advertising any routes leared from Phenox wheh the neighbour relationship between the two goes down?

    I look forward to your feedback.



    1. Hi Imran,

      It will no longer advertise network /24 anymore once this neighbor adjacency is down but it will still advertise /24.

      The key to this lab is that we don’t want to advertise /24 anymore once /24 disappears from the routing table of Pegasus.

      Keep in mind that network /24 is on the loopback from router Pegasus so it will be advertised to router Pixie.

  6. Thank you so much for your struggle and giving support other people , i really appreciate you work MR ReneMolenaar.

    I have simple question ,how can i ping pixie from phoneix ?

    i will be look forward for you appreciated reply.

    Thank you again.

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