CE Next-Hop-Self

[cassio.gomes]

Dear All,

I have this topology:

CE1-----CE2-----CE3

All routers are mpls vpn, and CE2 is router-reflector.

But CE1 can not see routes from CE3, becuase next-hop is invalid.

I have configured in CE2:

!

address-family ipv4 vrf A

neighbor VRFA peer-group

neighbor VRFA remote-as 65500

neighbor VRFA route-reflector-client

neighbor VRFA allowas-in

neighbor VRFA next-hop-self

neighbor 10.1.1.1 peer-group VRFA

neighbor 10.1.1.1 activate

neighbor 10.3.3.3 peer-group VRFA

neighbor 10.3.3.3 activate

no auto-summary

no synchronization

exit-address-family

!

but this config is not working.

I know that there is PBR config to set next-hop, but really do I need to use PBR?

Please, could you help me to solve this problem?

Thanks!

Cassio

[Harold Ritter]

Cassio,

This is no different than with a regular (non-vrf) BGP environment. The next-hop is not changed by the RR and the RR clients have to have a route in the RIB to resolve the BGP next hop for the route to be considered valid by BGP.

People usually configure nexthop-self on the RR clients or redistribute the access link IP addresses into the IGP so that the BGP next hop resolution takes place properly.

Hope this helps,

[cassio.gomes]

I'm a little confuse, but OK. I have configured loopback interface in IGP, of course that the problem was fixed, but the next-hop value was not changed, after this I have configured PBR to change next-hop, and it works fine.

Thank you very much

Cassio

[Harold Ritter]

Cassio,

I'm not sure I understand what the issue is.

- Why would need PBR?

- Do you mean that you configure a route-map to change the next hop on the RR?

- Why do you need to change the next-hop on the RR if you use next-hop self on CE1 and CE3?

- It is not recommended to change the NH on the RR.

Hope this helps,

[Harold Ritter · Accepted solution]

Cassio,

Sorry for the confusion. I see what you meant now. You are trying to apply next-hop-self on the RR.

next-hop-self will have no effect whatsoever on the routes reflected by the RR. It would only apply on eBGP learnt prefixes, in the RR had such connections of course.

Hope this helps,

[cassio.gomes]

Ohh, ok, I apologize for my English!

Thanks

Cassio

[Harold Ritter]

Cassio,

You are welcome. No need to apologize for your english as it is quite good. It would have helped if I had read your posting thoroughly the first time around.

Cheers,