Handling a large number of IPs efficiently

From: Bill Davidsen (davidsen_at_tmr.com)
Date: 12/27/03 

Date: Sat, 27 Dec 2003 10:45:19 -0500

I have a site which is going to want to allow access from certain site
only. A large number of sites, and not neatly grouped in CIDR blocks. A
few thousand IP addresses, in fact. Unfortunately iptables doesn't seem
to do this well, using a linear progression rather than a hash or similar.

I think I can do this using netlink socket, but before I jump in with
what looks to be an ugly solution, is there a better way I've missed? Or
a nice example of doing something similar with netlink? 

-- 
bill davidsen <davidsen@tmr.com>
   CTO TMR Associates, Inc
   Doing interesting things with small computers since 1979