Subject: [mobile-ip] How does HA use routing table?

From: Ichiro Okajima <[email-masked]>
Date: Mon, 04 Jun 2001 15:11:21 +0900

Hello all,

I would appreciate it if anyone would answer my question.
I think that the HA of Mobile IPv6 has a routing table as well as
Binding Cache since it is a kind of router. It seems to me that
Mobile IPv6 I-D does not say the relationship between the Binding
Cache and the routing table, and how to use the routing table.
My guess is as follows:

1) When the HA receives a packet, it firstly checks the Binding
Cache whether a binding for the destination address of the packet
exists or not.

2) If no binding exist in the Binding Cache, it secondly checks
the routing table to find the best route for the packet.

Is my understanding correct?

Ichiro

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From: "Qiang Zhang" <[email-masked]>
Date: Mon, 4 Jun 2001 13:56:31 -0500

I think for Agent to deliever the packet, the implication is that it should
follow the routing table, even there is a binding cache for a packet. Does
MIP have to address the issue?

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From: "Charles E. Perkins" <[email-masked]>
Date: Mon, 04 Jun 2001 11:29:56 -0700

Hello,

First, I concur with Ichiro Okajima's assessment of the intention
of the home agent procedure.

If the home agent has a binding for the mobile node, then that is
authoritative.  If there is a clash between the home agent's
routing table and its Binding Cache entry for the mobile node,
then that means something has gone wrong.  In fact, if the
home agent doesn't have a binding cache entry for the mobile
node, it typically shouldn't get the packet at all except insofar
as the home agent is a default router for the home network.
In that case, then its action is well defined, and typically it
still wouldn't have a host-specific route for the mobile node.

I usually consider the Binding Cache to be like a part of
the routing table anyway, with special flags.

Can someone suggest an improvement to the wording of the
Mobile IPv6 specification to clarify this?

Regards,
Charlie P.