>>>>> On Wed, 7 Dec 2005 13:18:28 -0500, 
>>>>> "Soliman, Hesham" <[EMAIL PROTECTED]> said:

>> > => Good points. I agree with that. So to keep it 
>> consistent, I'll remove this distinction
>> > between host and router. 
>> 
>> Okay, but please clarify my first question, too:
>> 
>> >> First of all, which part of the main text specifies this 
>> behavior?  As
>> >> far as I can see, the only text that explicitly mentions ICMPv6
>> >> destination unreachable error to be sent is in Section 
>> 7.2.2, where
>> >> the error is sent upon retransmit timeout for NS messages 
>> (which is
>> >> clearly a different scenario than this one).

> => This can be added to the text at the beginning of 7.2., which discusses 
> this issues. 

Hmm, so the behavior corresponding to the following entry (shown again
just to be accurate) is not currently described in the draft:

   INCOMPLETE      NA, Solicited=any,     Send ICMP error      unchanged
                   Override=any, No       (if router) or
                   Link-layer address     log error (if host)

then...we should discuss whether this behavior makes sense in the
first place.  Perhaps you added this entry based on a previous
discussion, but I don't remember such consensus.  So it would be great
if you can provide a pointer to the discussion.

In any case, I personally don't think this behavior makes sense.  It
at least violates a SHOULD requirement of Section 7.2.4 of
draft-ietf-ipv6-2461bis-05.txt:

   If the target's Neighbor Cache entry is in the INCOMPLETE state when
   the advertisement is received, one of two things happens.  If the
   link layer has addresses and no Target Link-Layer address option is
   included, the receiving node SHOULD silently discard the received
                                ^^^^^^^^^^^^^^^^^^^^^^^
   advertisement. [...]

Since the state is INCOMPLETE, this node should be doing link-layer
address resolution by sending multicast NSs.  In this case, the
responder MUST include the target link-layer address option per
Section 7.2.4:

   If the
   solicitation's IP Destination Address is a multicast address, the
   Target Link-Layer option MUST be included in the advertisement.

So, the event of receiving an NS with no link-layer address in this
state indicates the responder shows a non-compliant behavior.  I
believe it makes more sense to discard the bogus packets silently as
described in the body of the draft (Section 7.2.4) rather than taking
a specific action like sending an ICMPv6 error message.

                                        JINMEI, Tatuya
                                        Communication Platform Lab.
                                        Corporate R&D Center, Toshiba Corp.
                                        [EMAIL PROTECTED]

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