iBGP Full Mesh Routing Problem

[davidhuynh5]

Hello,

I've setup a iBGP full mesh and configured o-hst-cr-re01 as a route reflector client, but still can not ping 10.84.18.5 (ASN 64555) from o-hst-cr-re01. What am I doing wrong? Any help would be appreciated. Thank You.  

[Jon Marshall]

Follow normal troubleshooting procedure. 

Are the routes in the BGP table and the IP routing tables in each of the routers in the path. 

How far does a traceroute get from the source to the destination ? 

Jon

[chrihussey]

A lot to look at here but:

1- You have o-hst-cr-re01 configured as a route-reflector client to o-ew-cr-re01, yet o-hst-cr-re01 is IBGP peering with the other two routers in the AS. It shouldn't be that way. The o-hst-cr-re01 should just peer with o-ew-cr-re01, and not the others if it is to be a route reflector client.

2- Aside from that, it would probably best if it were to be a client to a directly connected peer and not one a couple hops away.

3- You could also have it be a client to the o-ee-cr-re01 and o-sa26-cr-re01 routers and use a cluster ID. Again if doing it that way, it wouldn't IBGP peer with o-hst-cr-re01.

Hope this helps

[davidhuynh5]

1- Agreed. I was try to build a full ibgp mesh, hoping that 10.84.18.1 (ASN 64999) could reach 10.84.18.5 (ASN 64555). It did not work, so I made 10.84.18.1 a RR client and 10.84.18.5 was still unreachable.

2. I not sure what you mean/

3. I will try that.

Thank You.

[Georg Pauwen]

Hello,

post the full config of the route reflector and the full config of o-ew-hb-re05 (in ASN 64555) as well...

[sivam siva]

The issue is o-ew-hb-re05  Don't know how to reach the o-hst-cr-re01 (10.84.18.1).

In your scenario o-ee-cr-re01 and o-sa26-cr-re01 doesn't send the 10.84.18.1 route to o-ew-cr-re01, because those routers learning that route from o-hst-cr-re01 so it will not send to  any other IBGP peer as per BGP split horizon rule. then how o-ew-hb-re05 knows about 10.84.18.1 ?!!

to get this resolve configure "neighbor 10.84.18.13 route-reflector-client" in o-ee-cr-re01 and o-sa26-cr-re01 (but this is not a best practices) then those routers send the 10.84.18.1 route to o-ew-cr-re01 as a BGP advertisement.

[davidhuynh5]

I configured 10.84.18.13 to be a RR client as suggested but still unable to ping 10.84.18.5 from 10.84.18.1.

[davidhuynh5]

Hey guys, I didn't advertise the WAN link between o-hst-cr-re01 and o-sa26-cr-re01 into iBGP...duh. I have reachablity to 10.84.18.5 now. Thanks for all your help.

[sivam siva]

Are you able to reach without configure command (neighbor 10.84.18.13 route-reflector-client) what I told ?