two locations with ospf into bgp and the same AS number

d.camargo · ‎05-19-2009

today I have a principal site where I am redistributing bgp into ospf in a router 7206, this is the central router for my branches and we are connected to a mpls-vpn cloud, the problem I have is connect a secondary link in the alternate site, I do not know how redistribute ospf over bgp in teh alternate site if I have the same AS numer?? and I do not want generate loops.

yclee_peter88 · ‎05-19-2009

Hi Camargo,

I don't really seem to understand your situation exactly, it would help if you could show me a network diagram illustrating your problem.

As far as I know, the AS number serves as a loop prevention mechanism in eBGP routing updates. You can override this behavior using the following BGP router configuration command:

neighbor x.x.x.x allowas-in

This command allows the other eBGP peer to accept BGP updates even when it see its own AS in the AS-PATH attribute.

Please rate if you find this helpful.

Peter Lee (CCNP, CCDP, CCIP, CCSP)