[151114] in North American Network Operators' Group
Re: filtering /48 is going to be necessary
daemon@ATHENA.MIT.EDU (Masataka Ohta)
Mon Mar 12 02:20:40 2012
Date: Mon, 12 Mar 2012 15:17:46 +0900
From: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
To: nanog@nanog.org
In-Reply-To: <CAP-guGUj6EYCOqQAd__QT=BPOpmRrv6BhtmHM-Mj=RQHFgzEwA@mail.gmail.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
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
