* Mike <mike+j...@willitsonline.com> > Im in a colo in one location (A), and have a private 1G ethernet > to another geographically distant colo (B). Each colo has a different > ip transit provider and I am advertising my own prefixes. At colo A I > receive a subset of Internet routes internal to that provider, while > at colo B I get full tables. Id like to like to exchange routes > between Colo A & B for better routing as well as for failover in the > event I lose ip transit at either location.
You don't need full tables for failover, getting a default from each provider will do fine for that purpose. However, what you could do with a cheaper device with limited FIB space is to take full feeds but be selective about which routes you download into the FIB. In JUNOS, you can control that with "set routing-options forwarding table export FOO". The assumption here is that you really don't care which transit provider is used for the odd packet destined for Timbuktu. So you can let those follow a default route to the colo-local provider, instead of wasting valuable FIB space on them. The routes or ASNs you do care about (i.e., the ones where you want nodes in colo A to cross your backbone link to colo B or vice versa, instead of exiting through the local transit), those you can selectively ensure get installed into the FIB. You could do so with static config, or you with a little more effort use flow telemetry to dynamically figure out, e.g., your top-10k destination routes and install those. If you insist on a router with a big FIB, expect to pay more for it, much much more. Keep in mind, though, that in all likelihood you will probably (almost) never send any packets to 95%+ of the prefixes that will be occupying your big and expensive FIB. Tore _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp