filtering /48 is going to be necessary

Mon Mar 12 06:17:46 UTC 2012

William Herrin wrote:

> C) Big iron is either using massively parallel FIBs (many copies of
> the radix tree) or they're using TCAM instead of DRAM, a specialized
> tristate version of SRAM. In either case, you're talking 10 to 100
> times the cost, ten times the power consumption and ten times the heat
> versus DRAM.

TCAM is a specialized version of CAM. CAM is much worse than SRAM.

> A router handling 10M routes is achievable today if we're willing to
> go back to $20k as the minimum cost BGP box. That's an order of
> magnitude more than we have now and three orders of magnitude short of
> where we need to be before we can stop sweating the prefix count.

For 16M routes, we only need /24.

With /24 aggregation, route look up is trivially easy with
a 16M entry single chip SRAM every 3ns consuming 1W.

That's why IPv4 or original IPv6 proposal with 8B address
is much better than the current IPv6.

						Masataka Ohta