Question : BGP with ISDN Backup

I have a problem with BGP and ISDN backup. What I want to achive is:

1. When the main link fails (in this case Frame Relay) - the eBGP route dies and I have a floating static with AD 200 pointing to Dialer1.
2. I then want Dialer 1 to dial the Main HQ Router - which it does.
3. I want the main link to then come back up - and for the peering to est and for the route from centre to come accross Frame Relay main link to Remote (this router). Which it doesnt????

Does anyone know why. I have denied BGP on the BRI interface and Dialer with an ACL (so that BGP doesnt keep the ISDN link up - like a passive-interface command in EIGRP - which you cant have on BGP).

Can anyone help???

Answer : BGP with ISDN Backup

Hi

Unfortunately BGP isn't my strong point, but I've got an observation that might point you in the right direction.

You have both the S0 interface and the Dialer configured as unnumbered, bound to Loopback0

This essentially means that they've got the same IP address.

When S0 goes down, the Dialer kicks in as it's the only valid route.
When S0 comes back, there's still traffic travelling down BRI0.

The traffic will still be getting to the correct next-hop.

When there's no traffic, the BRI0 is idle and shuts down.  At this point, and further traffic would go the S0 route.

Sorry that I can't give you a definitive answer, but I think that the problem is related to the above.

Are you able to configure different private addresses on the dialer and S0?
This is what I do to avoid confusion (because I'm a bear of very little brain).

Steve