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Date: Sat, 15 Jan 2005 21:46:54 -0500
From: Chuck Swiger <cswiger@mac.com>
Organization: The Courts of Chaos
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To: Julien Lesaint <julien+fbnet@titoon.net>
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cc: freebsd-net@freebsd.org
Subject: Re: ttl-exceeded sourced by arrival interface ?
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Julien Lesaint wrote:
> Quick reminder: in the case the route to the packet's source is not the
> interface this packet arrived on, do we have a way to source ICMP errors
> (ttl-exceeded) with the original interface's IP address ?

Yes.  Use IPFW's fwd mechanism, or even set a host route for the source IP 
address pointing to whichever interface you please.

> Currently the box is sending ttl-exceeded with the IP address of the
> interface the route to the sender is pointing at.

That's what the routing table is supposed to do, yes.

-- 
-Chuck