Subject: [MOBILE-IP] Proposed clarification to RFC2002bis

From: Henry Haverinen <[email-masked]>
Date: Wed, 8 Dec 1999 17:25:42 +0200

Hi all,

I recently sent a question concerning the entry point of
forward tunnels. The exact entry point of the forward tunnel is not
clearly specified in RFC2002bis. I think this might cause interoperability
problems.

Therefore, I'd like to propose one of the following clarifications to
be added to Section 4.2.3 of RFC2002bis:

Alternative 1

For multihomed home agents, the source address in the outer IP header of
the encapsulated datagram MUST be the address that the mobile node used in
the home agent field of the registration request. That is, the home agent
cannot use the the address of some other network interface as the source
address.

Alternative 2

For multihomed home agents, the source address in the outer IP header of
the encapsulated datagram can be the address of any network interface on
the home agent.

I prefer alternative 1.

Regards,
Henry

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From: "Charles E. Perkins" <[email-masked]>
Date: Wed, 8 Dec 1999 07:47:07 -0800

Hello Henry,

I saw your previous note, and I agree that we should make
a specification to avoid interoperability problems.

> cannot use the the address of some other network interface as the source
                 ........

> I prefer alternative 1.

Alternative 1 would be fine as long as the home agent could
still send the tunneled packets from any of its network
interfaces.  Alternative 2 sort of gives this freedom automatically.
Can you describe how specifying alternative 1 would be beneficial
for your implementation?

Regards,
Charlie P.