Subject: [mobile-ip] Mipv6 issue #139: 9.4.1 and 11.7.2 text in conflict about HAO in CN BUs

From: Jari Arkko <[email-masked]>
Date: Tue, 15 Oct 2002 17:49:31 +0300

According to 9.4.1, the HAO MUST always be present in BUs
sent to the CN. However, 11.7.2 says its a MUST unless src=hoa.

Proposal: It appears like fixing Section 9.4.1 is the right thing.
This is because when the MN returns home and de-registers from the
CN, HAO is not needed. This will also align HAO handling with the
way its done for HA and regular payload traffic.

Here's the changed text:

     -  The packet MUST contain a Home Address option.

=>

- The packet MUST contain a Home Address option, unless the Source
       Address is the home address of the mobile node

Jari

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From: Brian Haley <[email-masked]>
Date: Tue, 15 Oct 2002 12:00:59 -0400

>        Address is the home address of the mobile node

Hi Jari,

But then there's further text in at least two places that must also change:

  "If the Binding Update is valid according to the tests above, then the
   Binding Update is processed further as follows:

    -  If the Lifetime specified in the Binding Update is nonzero and
       the specified care-of address is not equal to the home address
       for the binding, then this is a request to cache a binding for
       the mobile node.  ...

    -  If the Lifetime specified in the Binding Update is zero or the
       specified care-of address matches the home address for the
       binding, then this is a request to delete the mobile node's
       cached binding. ..."

There is a "virtual" home address to compare of course, but the text
needs to say it might be absent.

Of course you could just change Section 11.7.2 and avoid all this, which
is what I would do.  Was the intention of not having to send a HAO simply
to conserve bits on the wire?

-Brian

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From: Jari Arkko <[email-masked]>
Date: Tue, 15 Oct 2002 20:58:32 +0300

> to conserve bits on the wire?

Not really, more like aligning this with the rest of HAO handling.
But I don't have a strong preference either way. But we have a couple
of folks agreeing with the fix-941 approach off the list so maybe
we should stick to that. If so, let's add after the bullet list
a new paragraph that tells how to find a "home address for the
binding" -- we already have a paragraph for the care-of address
which can also appear in different places.

    The home address for the binding MUST be determined as follows:

     -  If the Home Address destination option is present, the home
        address is the address in that option.

     -  Otherwise, the home address is the Source Address field in the
        packet's IPv6 header.

Jari

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From: gabriel montenegro <[email-masked]>
Date: Wed, 16 Oct 2002 17:20:53 +0200

>     -  Otherwise, the home address is the Source Address field in the

Agree, the above sounds like a good addition.

-gabriel