I recommend Darren Reed's IPfilter package, which comes with OpenBSD, and installs easily on FreeBSD and NetBSD. It also works with SunOS and Solaris, and I think even more operating systems. It is highly configurable. Blocking all incoming TCP connections except to a few host/port pairs should be quite simple. You can get it at ftp://coombs.anu.edu.au:/pub/net/firewall/ip-filter David