I have 2 sites peering with different ISP. I have advertising my own address space (192.168.254.0). both of my sites connceted via layer2 and have ibgp sesssions between my screen routers (AS 100). Site 1 is the primary site. All connections from the web routed via site 1.
Problem: when the south interface (eth1/1) on router 1 goes down, router 1 is still advertising 192.168.254.0 because router 1 and 2 both have static route for 192.168.254.0 to null 0 (by design - i cannot change it at this stage). What i would like to do it come up with a better solution so that when any of the south interface (eth1/1) is down i want Router 1 in site 1 to withdraw from adverting 192.168.254.0 prefix. I have looked at conditonal avertisement but dont think it will work for me....Need soe sort of interface tracking for bgp..