[30111] in North American Network Operators' Group
Re: Strange things which should never happen (was Re: RFC 1918)
daemon@ATHENA.MIT.EDU (Patrick W. Gilmore)
Sat Jul 15 03:10:49 2000
Message-Id: <4.2.2.20000715025643.03366320@ianai.net>
Date: Sat, 15 Jul 2000 02:58:45 -0400
To: nanog@merit.edu
From: "Patrick W. Gilmore" <patrick@ianai.net>
In-Reply-To: <20000715051456.22266.cpmta@c004.sfo.cp.net>
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At 10:14 PM 7/14/00 -0700, Sean Donelan wrote:
>I don't know my TCP/IP stack well enough, but what happens when a host
>with multiple interfaces, one of which is assigned an RFC1918 address,
>receives an packet through another interface with a source address the
>same RFC1918 address. Are the stacks smart enough to realize the packet
>is really an external packet, or will they assume the packet came from
>inside.
Nope - at least none of the ones I have seen.
Strictly speaking, the host *should* not care from which interface a packet
is received unless you have some type of firewall/filtering rule-set installed.
TTFN,
patrick
