Hi, I have a setup of ISP1 -- R1 -- LAN -- R2 -- ISP2 with BGP peerings from R1 to ISP1 and R2 to ISP2
Some hosts on the LAN have R1 as primary gateway, others R2 to distribute the load between the ISPs. I want to add a default route to the kernel on each router but only if the remote peer is up. The remote peer does not respond to BFD so that's not an option. Once both routers have a conditionally defined default route for their ISP, it should be easy to propagate that to each other with increased metric as a backup route. I am assuming here that if R1 has a default through R2 and ISP1 is down, R1 will respond with an ICMP redirect to any requests from hosts that need to be routed out of LAN. I searched for a recipe that would fit the above but found nothing yet, hoping someone here can help :) Nik
