Roger Fischer wrote:

> (It's been installed but wasn't my active firewall).
> 
> I'm running NetBSD 1.5.2 and I've got ipfilter set up and running.
                     ^^^^^
Others already mentioned ipmon. I hope you're not using plain NetBSD
1.5.2 (from an ISO image or download) as a firewall?
Several security advisories have been issued since 1.5.2 was released
in late 2000.  (see http://www.netbsd.org/Security/advisory.html).

You should really consider updating at least to the latest sources of
the 1.5 branch (CVS tag netbsd-1-5-PATCH003).

ciao
     Klaus