nanog mailing list archives
Re: Software router state of the art
From: "William Herrin" <herrin-nanog () dirtside com>
Date: Sat, 26 Jul 2008 09:35:59 -0400
On Sat, Jul 26, 2008 at 7:41 AM, Dorn Hetzel <dhetzel () gmail com> wrote:
Ok, it's probably a stupid question, but given the relative ease of putting 4gb+ ram on a 64bit platform, could packet per second performance be improved by brute forcing the route lookup as an array of 1 byte destination interface indexes for a contiguous swath of /32's from bottom to top? Route updates would be a little ugly, 2^24 bytes to rewrite for a /8, but forwarding lookups out to be a single indexed read ?
Dorn, In theory with about 6 gigs of ram for the IPv4 FIB, sure. But: You're significantly multiplying the likelihood of a cache miss when performing a lookup. You can do a fair amount of tree traversal in cache for the price of one miss. You're a tad shy on ram to try this with IPv6. Regards, Bill Herrin -- William D. Herrin ................ herrin () dirtside com bill () herrin us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
Current thread:
- Re: Software router state of the art, (continued)
- Re: Software router state of the art Sargun Dhillon (Jul 25)
- Re: Software router state of the art Joe Greco (Jul 25)
- Re: Software router state of the art Adam Armstrong (Jul 23)
- Re: Software router state of the art Chris Adams (Jul 23)
- Re: Software router state of the art Jeffrey Ollie (Jul 23)
- Re: Software router state of the art Florian Weimer (Jul 26)
- Re: Software router state of the art Adrian Chadd (Jul 26)
- Re: Software router state of the art Colin Alston (Jul 26)
- Re: Software router state of the art Adrian Chadd (Jul 26)
- Re: Software router state of the art Dorn Hetzel (Jul 26)
- Re: Software router state of the art William Herrin (Jul 26)
- Re: Software router state of the art Florian Weimer (Jul 26)
- Re: Software router state of the art Tony Finch (Jul 27)
- Re: Software router state of the art Joe Greco (Jul 26)
- Re: Software router state of the art Sargun Dhillon (Jul 28)
- Re: Software router state of the art Joe Greco (Jul 28)
- Re: Software router state of the art Rubens Kuhl Jr. (Jul 28)
- Re: Software router state of the art Eugeniu Patrascu (Jul 28)
- Re: Software router state of the art Seth Mattinen (Jul 28)
- RE: Software router state of the art michael.dillon (Jul 28)
- Re: Software router state of the art Justin Sharp (Jul 28)