Subject: [mobile-ip] issues 92, 94, 95 and text for sending BAs with RH

From: Jari Arkko <[email-masked]>
Date: Mon, 19 Aug 2002 12:38:26 +0300

I have updated the text proposals to fix issues
#92, #94 and #95 based on comments I received. Namely, we do not
want to prevent site-local addresses from using mobility. Also,
the text becomes simpler if the condition for using RH is the presense
of HAO in the BU.

New text for 9.4.4:

   The acknowledgement is sent to the Source Address of the IPv6 header
   that carried the Binding Update. Note that this procedure is
   independent from the treatment of regular packets and does not use
   information from the Binding Cache.

   If the Source Address field does not contain a site-local or global
   unicast address, the Binding Acknowledgement MUST NOT be sent.

   Otherwise, further processing depends on whether or not the Binding
   Update contains a Home Address destination option. If it does, the
   source address is the home address of the mobile node and the
   Binding Acknowledgement MUST be sent directly to this address.
   Otherwise, the Binding Acknowledgement MUST still be sent to the
   source address but a Type 2 Routing Header MUST be added to the
   packet to carry the home address.

And for 10.2:

   The acknowledgement is sent to the Source Address of the IPv6 header
   that carried the Binding Update. Note that this procedure is
   independent from the treatment of regular packets and does not use
   information from the Binding Cache.

   If the Source Address field does not contain a unicast address, the
   Binding Acknowledgement MUST NOT be sent.

   Otherwise, further processing depends on whether or not the Binding
   Update contains a Home Address destination option. If it does, the
   source address is the home address of the mobile node and the
   Binding Acknowledgement MUST be sent directly to this address.
   Otherwise, the Binding Acknowledgement MUST still be sent to the
   source address but a Type 2 Routing Header MUST be added to the
   packet to carry the home address.

---

From: Brian Haley <[email-masked]>
Date: Mon, 19 Aug 2002 10:38:41 -0400

Jari,

I'm confused, all Binding Updates must contain a Home Address option,
so that check is always true.  I thought draft 15 had good text about this:

 "Furthermore, if the packet
   is to be sent to the mobile node at any address other than the mobile
   node's home address, it MUST be sent using a Routing header (even if
   the binding was rejected)."

The point being that if the source and home address are equal, we don't
use a Routing Header.  At Cthon 2002 we agreed this was good since
we're conserving bytes on the wire(less).

Your third paragraph in each of these below seems to contradict itself:

1) If a HAO is present, the BAck must be sent directly to this address.
    This implies no route optimization.

2) If a HAO is not present, the BAck is sent to the source of the packet
    with the home address in the T2 RH.  But in this case we don't have
    a home address to put in the RH.

-Brian

---

From: Jari Arkko <[email-masked]>
Date: Tue, 20 Aug 2002 01:16:49 +0300

> so that check is always true.  I thought draft 15 had good text about this:

It seems that there's even more to fix: 6.1.7 allows optional HAO. For CNs,
9.4.1 always requires a HAO but 11.6.2. allows optional HAO. For HAs, 11.6.1
10.2, and 10.3 all agree that a HAO is needed. My mistake...

So, this should be fixed as always requiring a HAO, even when sending from
the home address?

> we're conserving bytes on the wire(less).

Agree with this.

>     a home address to put in the RH.

Yes, the third paragraph is bad... The intention was to say that if HAO
is present, then include a T2 RH. And if the HAO is not present, then
send directly.

Based on this and the above, we need a new third paragraph.

Jari