On Dec 19, 2008, at 10:48 AM, Joe Greco wrote:
As for routing table size, no router which can handle 10s of Gbps is at all bothered by the size of the global table,
... as long as it isn't something like a Cisco Catalyst 6509 with SUP720 and doesn't have a PFC3BXL helping out ...
... or if we conveniently don't classify a Catalyst 65xx as a router because it was primarily intended as a switch, despite how ISP's commonly use them ...
so only edge devices or stub networks are in danger of needing to filter /24s. And both of those can (should?) have something called a "default route", making it completely irrelevant whether they hear the /24s anyway.
A more accurate statement is probably that "any router that can handle 10s of Gbps is likely to be available in a configuration that is not at all bothered by the current size of the global table, most likely at some substantial additional cost."
Good point! I should have said "10s of Gbps and tables associated with default-free networks". Or are there lots of people using 6500s without 3BXLs in the DFZ? I admit I have not audited every router in the DFZ, so perhaps someone with factual info can help out here. If not, then we're back to where we started. The DFZ isn't worried about table size this cycle, and the edges can (should?) have default. I'm sure that will change in a couple years, but everything always does. Oh, and before anyone jumps all over me, I am NOT implying you should deaggregate and blow up the table. Just that 300K prefixes is the DFZ is not a reason to start filtering /24s. Today. :) -- TTFN, patrick