Lost in BGP

[jaybizzel]

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

[Giuseppe Larosa]

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]

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

[Giuseppe Larosa]

Hello Harold,

thanks I had missed the change

10.0

This command was introduced.

12.0(7)T

Address family configuration mode was added.

>>>12.2(8)T

>>>Command default behavior changed to disabled.

http://www.cisco.com/en/US/docs/ios/iproute/command/reference/irp_bgp5.html#wp1018615

Best Regards

Giuseppe

[jaybizzel]

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]

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]

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]

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]

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]

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