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