iBGP question

oswaldo81 · ‎10-20-2008

Hi,

does anybody know if the following is possible.........

1. I have server X (just a made up name) with an iBGP session to a Cisco router.

2. Server X announces routes to the router with no-advertise and no-export communities set - the router enforces this with an inbound route-map.

3. The router has an iBGP session with a route log server as well a many other iBGP sessions to other routers.

Q. When the router receives a route with the communities set as in 2 from server X, is it possible to make the router advertise this route only to the route log server (for route audit purposes) but to honour the no-advertise community for all other iBGP peerings?

It is not possible to make the server iBGP peer directly with the route log server because the server X cannot be trusted.

Ideally, I don't want to be putting lots of outbound filters on all of the routers iBGP peerings.

Thanks for your time!

Regards,

Alan

Giuseppe Larosa · ‎10-20-2008

Hello Alan,

>> Q. When the router receives a route with the communities set as in 2 from server X, is it possible to make the router advertise this route only to the route log server (for route audit purposes) but to honour the no-advertise community for all other iBGP peerings?

you should remove the no-advertise community on the inbound route-map when the prefix is received, but then you need to use a route-filter to avoid to send it to all other iBGP peers.

So the short answer should be no without route-filters or all iBGP receive it for the inbound removal of no-advertise or none will receive it if you leave the no-advertise community untouched

Hope to help

Giuseppe