A router which needs to be looked at if you are serious about setting up a
firewall for your network is the Network Systems Router. It has standard as
part of the software filtering for any direction of traffic, IP address
wildcarding, port filtering on TCP and UDP both source and destination and
also supports RFC1038 and RFC1108 and also DNSIX support for the security
conscious in the Federal Government. Let me know if you want to here more.
Thanks for your ear and eyes :-).
Network Systems Corporation