Subject: [MOBILE-IP] a comment of draft-ietf-mobileip-ipv6-12.txt

From: JINMEI Tatuya / 神明達哉 <[email-masked]>
Date: Fri, 9 Jun 2000 02:42:45 +0900

Before finishing the last call for the mobile IPv6 draft, I'd like to
comment on the draft.

I hope this is not too late, and apologize in advance if this has
already been discussed.

Section 10.2 of the draft says as follows:

    -  Since the mobile node is away from home, the mobile node inserts
       a Home Address option into the packet, replacing the Source
       Address in the packet's IP header with a care-of address suitable
       for the link on which the packet is being sent, as described in
       Section 10.1.  The Destination Options header in which the Home
       Address option is inserted MUST appear in the packet before the
       AH [11] (or ESP [12]) header, so that the Home Address option is
       processed by the destination node before the AH or ESP header is
       processed.

It seems to me that the order of the destination options header
including the home address option is not conformant to the recommended
order of extension headers specified in RFC 2460:

   When more than one extension header is used in the same packet, it is
   recommended that those headers appear in the following order:

           IPv6 header
           Hop-by-Hop Options header
           Destination Options header (note 1)
           Routing header
           Fragment header
           Authentication header (note 2)
           Encapsulating Security Payload header (note 2)
           Destination Options header (note 3)
           upper-layer header

           note 1: for options to be processed by the first destination
                   that appears in the IPv6 Destination Address field
                   plus subsequent destinations listed in the Routing
                   header.

           note 2: additional recommendations regarding the relative
                   order of the Authentication and Encapsulating
                   Security Payload headers are given in [RFC-2406].

           note 3: for options to be processed only by the final
                   destination of the packet.

At least for me, the above order assumes that a destination options
header placed before an authentication header (or an ESP) should also
be accompanied with a routing header. However, the mobile IPv6 draft
does not mention a routing header at all (I guess the draft does not
care about a routing header).

Is my concern about the order correct? If so, at least I want the
draft to describe the intention of the unrecommended order and
possible effects on implementation.

Thanks,

                                        JINMEI, Tatuya
                                        Communication Platform Lab.
                                        Corporate R&D Center, Toshiba Corp.
                                        [email-masked]

---

From: AIme Le-Rouzic <[email-masked]>
Date: Fri, 9 Jun 2000 09:09:18 +0200

Hi,

In fact, the Home Address has to be also BEFORE the fragment header to
allow firewalls to read it. Those firewalls
can be on other destinations than those listed in the Routing Header.

May be it needs to clarify to put a recommendation in RFC2460 or
in the next RFC MobileIPv6  this special case.

Best regards

--
     ________________________Aime LEROUZIC____________________________
     BULL S.A ECHIROLLES FRANCE      mailto:[email-masked]
     http://www-frec.bull.com                tel: +33 (0)4 76 29 75 51
     Communications TCPIP                     http://intranet/lerouzic

---

From: JINMEI Tatuya / 神明達哉 <[email-masked]>
Date: Mon, 12 Jun 2000 17:10:50 +0900

>>>>> On Fri, 09 Jun 2000 09:09:18 +0200,
>>>>> AIme Le-Rouzic <[email-masked]> said:

> in the next RFC MobileIPv6  this special case.

Hmm, in any case, I hope the mobile IPv6 specification clarifies the
ordering as long as it dares to break the recommendation in RFC2460
(which is already a draft-standard RFC), before the spec proceeds to
an RFC status.

                                        JINMEI, Tatuya