On 7/Mar/15 15:50, Nick Hilliard wrote: > On 07/03/2015 05:25, Mark Tinka wrote: >> My BGP-SD route-map includes communities and other necessary match >> conditions that identify prefixes I'd like to download into FIB. > but you can only use table-map with a deny-all route-map if the PE is a > pure edge device, i.e. if all traffic is either local or north-south and > you can get away with just a default route and connected/static routes.
I agree that if it's an edge device with a stub or direct upstream, e.g., a CPE device connected to an upstream ISP, then this makes sense. But an edge device in an PoP used to terminate customers makes a north-south topology interesting because if the ISP distributes routing with no other router in the PoP acting as a default gateway, you end up with the problem of which other router to use as your default gateway. If you operate a BGP-aware core, then pointing default or specifics to the core router in the PoP is an option (you still trombone traffic destined for other non-core routers within the PoP, however...). But if you operate a BGP-free core, then it becomes interesting which box you choose to point default or specifics to on the back of a "deny-all" BGP-SD route-map. We deploy some ME3600X's within a PoP as edge routers for customers, but these do not require any global BGP routes anyway. So use of BGP-SD in this case is redundant. > East-west traffic necessarily depends on visibility into the rest of the > network, which increases the risk of booboos. Yes, this is where we deploy BGP-SD, as unlike the ME3600X's deployed in the case mentioned above, these require global BGP routes. Mark. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
