We have a few customers who have connections to two different POPs both on our network. In these cases, we’ve started deploying an RB2011 or similar as the CPE router that manages the two “upstream” connections for them. This router is configured to use OSPF to communicate with our POP routers and redistribute the customer’s assigned network.
Of course, the hazard with this setup is that if POP A has no available backhauls for whatever reason, it then sees the customer and their link to POP B as a valid route out. Given that we’re not engineering our customer links as main backhauls, this has caused a bit of a problem when it happened recently, and now I’m tasked with figuring out how to prevent the customer CPE from redistributing any routes except the “local” ones – if POP A has no available backhaul sites, it should go down rather than using the customer site to relay to POP B.
About the closest thing I can find would be to apply route tags with an “in” filter on the customer’s router, and then drop any outbound routes with that route tag. Given that I have limited time to play with things these days (don’t we all?), I was hoping someone else had already run across this and comment on the procedure. Will the route tag approach even work? Is there another better method to accomplish the route filtering I need? We just recently got all of our IGP converted to OSPF instead of mixing and matching with iBGP, and I’d rather keep a homogenous setup if I can.
