Lost in BGP

Unanswered Question
Jan 5th, 2009

hi all. am a BGP beginner. using GNS3 i tried to configure BGP but the internal router is not trusting the route coming from its nei in the same AS. i used the route-reflector command, it didnt work also tried the next-hop-self command but didnt work also. please can i get direction on how to go about it. thanks all

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Overall Rating: 4.7 (3 ratings)
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Giuseppe Larosa Mon, 01/05/2009 - 06:47

Hello Jay,


you probably need to disable synchronization if the route is not advertised in a IGP


router bgp xx

no sync


With sync on (default) the iBGP route is accepted, installed and advertised if it is known in the IGP in use (OSPF, EIGRP ...)



Hope to help

Giuseppe


Harold Ritter Mon, 01/05/2009 - 12:36

Giuseppe,


Just one precision. The default is now to have synchronization disabled by default. That has been changed a long time ago (12.2T I believe).


Synchronization might still be the issue depending on the software version that was used in this specific case.


Regards

jaybizzel Tue, 01/06/2009 - 00:28

oh thanks for your support. i have been able to rectify the problem but another problem now comes up. i see this sign r> on routes coming from an internal router in the same AS. what does it mean?

jaybizzel Tue, 01/06/2009 - 00:46

oh thanks for your support. i have been able to rectify the problem but another problem now comes up. i see this sign r> on routes coming from an internal router in the same AS. what does it mean?

Harold Ritter Mon, 01/05/2009 - 12:38

Jerome,


Can you provide a "show ip bgp " for the specific prefix that is not accepted. This should tell you what is causing the issue.


Regards

jaybizzel Tue, 01/06/2009 - 00:28

oh thanks for your support. i have been able to rectify the problem but another problem now comes up. i see this sign r> on routes coming from an internal router in the same AS. what does it mean?

Giuseppe Larosa Tue, 01/06/2009 - 01:09

Hello Jay,

a r sign means that the route is received but it is regarded as not totally correct

r means RIB failure.


It may mean the local router has a better route for the prefix then the one received in iBGP


try to compare


sh ip bgp


and

sh ip route


Hope to help

Giuseppe


jaybizzel Tue, 01/06/2009 - 01:19

thanks giuseppe. the meaning was a lower cost route was present in the IP routing table. you are the best.

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