Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucsd!brian
From: brian@ucsd.Edu (Brian Kantor)
Newsgroups: comp.unix.wizards
Subject: Re: How do I set up an insulating gateway?
Message-ID: <10051@ucsd.Edu>
Date: 10 Oct 89 06:02:20 GMT
References: <29942@watmath.waterloo.edu> <459@usage.csd.unsw.oz>
Reply-To: brian@ucsd.edu (Brian Kantor)
Organization: The Avant-Garde of the Now, Ltd.
Lines: 2

Or compile the kernel with the "ipforwarding" variable turned off, eh? 
I suppose you could poke it with ADB if you don't have source.