Firewall is a set of scripts (firewall, fwup, and fwdown) that implement an
ipchains firewall and various forms of network address and port translation.
All you have to do is read the policy file and edit it to reflect your topology
and filtering policy. It supports many different types of network topology
(single host, traditional forwarding, masquerading, port forwarding, alias port
forwarding and NAT), up to 10 untrusted interfaces each with their own policy,
and over 50 network applications. It also supports centralised administration
of multiple remote firewalls (meta-firewall).
