Subject: [mobile-ip] Proposed resolution for issue #92

From: "Charles E. Perkins" <[email-masked]>
Date: Thu, 24 Oct 2002 12:43:19 -0700

Hello folks,

I believe issue #92 has become a moot point after the
recent resolutions of other issues, because typically
error 137 will not be sent, thus eliminating any possibility
for the reflection attack.  The other part of issue #92
discussion has to do with choice of destination address
for the Binding Acknowledgement, and the new rule seems
to take care of all the cases I could find.  Here it
is, for convenience, as currently to be found towards
the end of section 9.4.4:

   If the Source Address field does not contain a unicast address, the
   Binding Acknowledgement MUST NOT be sent, and the Binding Update
   packet MUST be silently discarded.  Otherwise, the acknowledgement
   MUST be sent to the Source Address of the IPv6 header that carried  
   the Binding Update.  Unlike the treatment of regular packets, this
   addressing procedure does not use information from the Binding Cache.
   If the Source Address is not an address of the mobile node on its
   home network, then the Binding Acknowledgement MUST be sent using a
   Type 2 Routing Header which contains the mobile node's home address.
   Otherwise, the routing header MUST NOT be used.

I propose that the issue is now to be considered resolved, unless
there is further discussion about use of the link-local address
for home deregistrations.

The full text of the issue discussion can be found at the following URL:
   http://www.piuha.net/~jarkko/publications/mipv6/issues/issue92.txt

Regards,
Charlie P.