Thanks for the info. We are in a carrier neutral facility with our current link being via the colo space provider which has 6gbps of connectivity to several Tier 1 providers. We are considering adding a link to 1 or more providers directly to reduce dependency on the colo provider's network. Even a $500 a month cheap Cogent (in the building) link will be enough during a failure. In the colo arrangement we are billed (from what I have been told) based on 95% usage.
We are looking at building redundancy to multiple providers with R1 going to the colo and our direct links via R2.
With uplinks from both routers, then BGP can take over in that scenario.
The main concern is if we lose the local side of the router, under the current single uplink scenario, we will be able to route out R2, currently the colo provider is forwarding traffic to R1 IP only. We would like to be able to pass that traffic to R2 should there be a partial router failure (interface, cable, etc..).
If we use OSPF and only use connected subnets, that would help the situation, but R1 needs to know that the route of last resort is via R2 if the WAN and/or LAN sides are down on eaither router.
I was thinking of something like this.. I hate static routes, but it will work. If this runs over a NM-1Exx on each router, then the failover is not dependent on any of the VRRP interfaces. It will be slower, but it will be up.
ip route 0.0.0.0 0.0.0.0 R2 100
ip route 1.2.3.4 255.255.255.252 R2 100
If I use route maps, can they be applied to the interface instead of sub-interfaces? This will simplify the config if additional subs are added later.
thanks
