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New Member

ibgp peering

I am trying to establish my ibgp peering.  The routers are three ip hops away from each other and we use eigrp for our igp.  Nothing I have tried works.  Any assistance is appreciated.  I am able to ping loopback to loopback without bpg running.  My loopbacks are 172.20.232.23 (PC) and 172.18.232.23 (SMC).  I am unable to ping between them with bgp running.  Also, I am able to successfully establish the peering.  Since I can't ping between the loopbacks when the session is established, the session times out after three minutes and reestablishes.  The one thing I am seeing in debugs is a "recursion error routing 172.20.232.23 -  possible routing loop" after the peering is established.  Here is the rest of the debug leading to this message:

recursion.bmp

Here are my configs:

PC-ASR

snap005.bmp

SMC-ASR

snap009.bmp

Here are the show ip bgp results:

PC-ASR

snap007.bmp

SMC-ASR

snap008.bmp

Thanks

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Bronze

Re: ibgp peering

At one end, you are summarizing and BGP will have a more specific route.

You have 2 choices, either remove the summary in EIGRP or do not advertise the loopbacks in BGP.

5 REPLIES
Hall of Fame Super Bronze

Re: ibgp peering

The loopback should be installed in the BGP table with a RIB failure and I don't see that in your BGP table output.

Can you post the EIGRP route table containing the loopback prefix at either end?

Recursive routing means you are learning the destination via the same process. In this case, you are learning the loopback via BGP but you are using the loopback to establish the BGP peering hence the term recursive.

If you are summarizing in the transit path, the loopback prefix advertised via BGP will be chosen as it has a longer subnet mask.

Regards,

Edison

New Member

ibgp peering

Here is the table from SMC to 172.20.232.23.

Here is the same from PC to 172.18.232.23.

Thanks,

Gregg

Hall of Fame Super Bronze

Re: ibgp peering

At one end, you are summarizing and BGP will have a more specific route.

You have 2 choices, either remove the summary in EIGRP or do not advertise the loopbacks in BGP.

New Member

ibgp peering

After reading your fist post more closely (after submitting my first response) I removed the network statemnet from my bpg configs.  I was able to ping between loopbacks.  Thanks for the assistance.

Now I can get on to my ebgp peerings.

Thanks,

Gregg

Hall of Fame Super Bronze

ibgp peering

Please rate the thread as resolved.

Regards,

Edison

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