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AS-Path issues

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

HTH, John *** Please rate all useful posts ***
7 REPLIES
Hall of Fame Super Blue

Re: AS-Path issues

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

Re: AS-Path issues

Reposted in another message with attachments

HTH, John *** Please rate all useful posts ***

Re: AS-Path issues

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

HTH, John *** Please rate all useful posts ***

Re: AS-Path issues

Hello John.

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

Simon

Re: AS-Path issues

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

HTH, John *** Please rate all useful posts ***

Re: AS-Path issues

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

Re: AS-Path issues

Simon,

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

Thanks,

John

HTH, John *** Please rate all useful posts ***
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