FYI,

screend is a daemon/kernel-patch for BSD operating systems that can be
used to construct an intelegent packet filtering gateway.  Such a
gateway would be used when building an internet firewall.

The reference I have to screend is:

	ftp://ftp.vix.com/pub/vixie/screend-960126.tar.gz

which was taken from Chapman's Firewalls book.  A preliminary glance
through it suggests that it should for the most part just drop in.

To be honest, I'm supprised that someone didn't simply integrate it into
the NetBSD-1.1 kernel.  While it may not be the perfect packet filtering
system, it at least, appears to both be fairly well known and come off
the shelf.

				enjoy, Andrew