nanog mailing list archives
Re: filtering /48 is going to be necessary
From: William Herrin <bill () herrin us>
Date: Sat, 10 Mar 2012 18:11:09 -0500
On Sat, Mar 10, 2012 at 5:47 PM, Sven Olaf Kamphuis <sven () cb3rob net> wrote:
just get routers with enough memory... i'm rather for a "specification" of a minimum supported route-size (let's say something along the lines of 64GB in each border router, it's 2012 after all ;) than for putting limits on the prefix sized announced so "old junk" can still stay connected to the internet. let's say, there is 6 billion people in the world.. if they all have 1 route table entry (average ;) i see no technical limitations on anything produced AFTER 2008 actually. stop buying crap without sufficient ram, or just scrap it and get new stuff. (which you're going to have to do to efficiently route ipv6 -anyway- at some point, as your old stuff, simply doesn't even loadbalance trunked ethernet ports properly (layer 3 based) ;)
Sven, A) 7 billion people in the world, not 6. B) 7B IPv6 routes won't fit in a 64GB radix tree once, let alone the several times they'd need to in order to be useful in a router. For that matter, 6B routes won't fit either. (Hint: FIB plus at least one RIB for each peer) 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. D) No computer presently exists on which the BGP protocol could keep up with today's update rate per prefix with 7B prefixes. 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. Regards, Bill Herrin -- William D. Herrin ................ herrin () dirtside comĀ bill () herrin us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
Current thread:
- Re: filtering /48 is going to be necessary, (continued)
- Re: filtering /48 is going to be necessary Owen DeLong (Mar 09)
- RE: filtering /48 is going to be necessary Leo Vegoda (Mar 09)
- Re: filtering /48 is going to be necessary Owen DeLong (Mar 09)
- Re: filtering /48 is going to be necessary Joel jaeggli (Mar 09)
- Re: filtering /48 is going to be necessary Randy Bush (Mar 09)
- RE: filtering /48 is going to be necessary George Bonser (Mar 09)
- Re: filtering /48 is going to be necessary Joel jaeggli (Mar 09)
- RE: filtering /48 is going to be necessary George Bonser (Mar 09)
- Re: filtering /48 is going to be necessary Jimmy Hess (Mar 10)
- Re: filtering /48 is going to be necessary Sven Olaf Kamphuis (Mar 10)
- Re: filtering /48 is going to be necessary William Herrin (Mar 10)
- Re: filtering /48 is going to be necessary Masataka Ohta (Mar 11)
- Re: filtering /48 is going to be necessary Seth Mattinen (Mar 10)
- Re: filtering /48 is going to be necessary Joel jaeggli (Mar 10)
- Re: filtering /48 is going to be necessary Owen DeLong (Mar 10)
- Re: filtering /48 is going to be necessary Sven Olaf Kamphuis (Mar 10)
- Re: filtering /48 is going to be necessary Jared Mauch (Mar 12)
- Re: filtering /48 is going to be necessary Sven Olaf Kamphuis (Mar 10)
- Re: filtering /48 is going to be necessary Owen DeLong (Mar 10)
- Re: filtering /48 is going to be necessary Jimmy Hess (Mar 09)
- RE: filtering /48 is going to be necessary George Bonser (Mar 09)