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Date: Tue, 24 Oct 2000 11:48:40 -0400 (EDT)
From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>
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To: Mike Nowlin <mike@argos.org>
Cc: freebsd-net@FreeBSD.ORG
Subject: src IP addr w/multiple ifaces
In-Reply-To: <Pine.LNX.4.21.0010240230560.9980-100000@jason.argos.org>
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<<On Tue, 24 Oct 2000 02:39:54 -0400 (EDT), Mike Nowlin <mike@argos.org> said:

> How is this source IP chosen in the kernel

If the source address is ``bound'' (either by the socket or by the
protocol if there is no socket), then that source address will always
be used.

Otherwise, the source address is chosen to be the interface address
associated with the route to the destination, or the interface address
of the interface the destination is attached to if routing is
disabled.

This algorithm was chosen so that the Right Thing happens on
multi-homed hosts where not all communication partners have routes to
all addresses.

-GAWollman



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