We've been using the Linux Virtual Server project (which a previous poster mentioned) to do load balancing (locally) on web based apps, pop3, smtp and now iptable firewalls. It scales well, has multiple lb algorithms (wlc, rr, lc, wrr, etc.) and even multicasts out the connection info if you want so you can set up a bank of redundant lb's. It can work w/ NAT or ip tunneling or direct routing so it might be able to do global load balancing depending on the setup. We have a 10000+ user mail farm behind one and haven't seen a single hiccup... http://www.linuxvirtualserver.org/ -- Don Mills