Subject: Re: Strange packet redirection
To: Rick Byers <>
From: John F. Woods <>
List: current-users
Date: 05/20/1999 17:38:06
> I've got a NetBSD-1.4 machine doing for my local network (192.168.149.*)
> over my cable modem.  I have a WEIRD situation where the gateway machine
> is redirecting packets to itself when it should just be translating the
> source address.

> For example, if (from my PC at I telnet to,
> it establishes a connetion with the gateway machine instead!  tcpdump on
> the internal network shows what I would expect, but the gateway machine
> never sends the packets out, it just handles them itself.  This has
> happened with a few other (seemingly random, but I didn't look hard)
> destination IP addresses.  If I clear ALL NAT rules and flush the NAT
> table, this still happens.

This is happening on my PC without NAT being configured at all!  I believe
there is something badly broken in the forwarding code that is allowing the
forwarder to conclude that completely random addresses are local, but there
is nothing obvious in a quick inspection of the code.