AS-Path issues

[John Blakley]

All,

I've got a "simple" situation that I figured would be easy, but it's not working. I've attached a topology diagram for reference.

I've got routes from the "RTA" router that are advertised to ISP. The RTA router sees two paths to RTB: through ISP and through OM.

RTB only sees one path to 192.168.1.0 (RTA), and that's through the ISP. All BGP neighbors are up, and these are all eBGP peers. The OM router has the route for 192.168.1.0/24 in it's table through 172.16.1.1 (RTA), but OM isn't advertising that route to RTB.

I need to have RTA accessible over the OM link in case the link between RTA and ISP goes down. I was going to modify the ASPath to do this, but it does no good if I'm not getting the routes to RTB. =)

Any ideas?

Thanks!

John

[Jon Marshall]

John

Could you provide a few more details.

Which ASs are the routers in - oops just reread your post an all routers are EBGP peers so don't worry about this bit.

Can you provide configs of the routers BGP config

Can you provide "sh ip bgp" and "sh ip route" from routers.

Jon

[John Blakley]

Reposted in another message with attachments

[John Blakley]

Jon,

This would be extremely long output, so I'm going to show just two routers: OM and RTB. All of the other routers seem to be okay.

I've attached two text files. I can't get RTB to advertise the routes to the ISP that it's learning from OM.

Thanks!

John

[simontibbitts]

Hello John.

This is confusing now as your outputs don't show any 192.168.x.x routes at all?

Simon

[John Blakley]

Jon,

This was done in gns in anticipation in what I'm going to need to do in production. Nothing was changed, but I exited out of gns, reloaded, and everything started working..

Thanks,

John

[simontibbitts]

Hi John.

Can you please paste a 'show ip bgp 192.168.1.0' from each node and also a 'show ip bgp neighbor [RTB-IP] advertised-routes'

Simon

[John Blakley]

Simon,

Sorry about the confusion. I changed some addresses around waiting for a response :) Everything seems to be working now.

Thanks,

John