North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Route table growth and hardware limits...talk to the filter
On Sun, 9 Sep 2007, Randy Bush wrote:
IIRC, this has come up on cisco-nsp before, and the response has been that it's very "icky" to do and doesn't really save anything on most platforms. In the example case of 1) 192.168.0.0/16 AS11111 AS22222 AS33333 2) 192.168.1.0/24 AS11111 AS22222 AS33333 3) 192.168.2.0/24 AS11111 AS55555 AS44444 AS33333 4) 192.168.3.0/24 AS11111 AS22222 AS33333 Forrest says the router should be smart and reject paths 2 and 4 because they're covered by 1. Now what happens when 1 is revoked? Do we lose connectivity to 2 and 4, or does the router have to keep track of all these dependant routes and reinstall 2 and 4 when 1 is lost? Granted, the overhead involved would maybe be worth it on a platform like the 6500/7600, where you can end up with a surplus of RAM and not enough TCAM, if only the "active" routes were stored in TCAM, but it's not exactly in cisco's best interest to extend the life of gear they'd like to see replaced with new cisco gear. I just can't understand why they won't/haven't done a Sup32-3bxl for those using this platform but not moving enough Gbps to need the traffic capabilities of the Sup720-3bxl. ---------------------------------------------------------------------- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net | _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________
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