Subject: 6MAN WG Last Call:draft-ietf-6man-overlap-fragment-01.txt

From: Brian Haberman <[email-masked]>
Date: Mon, 02 Mar 2009 09:32:33 -0500

All,
      This message starts a 2-week 6MAN Working Group Last Call on 
advancing:

         Title     : Handling of overlapping IPv6 fragments
         Author(s) : S. Krishnan
         Filename  : draft-ietf-6man-overlap-fragment-01.txt
         Pages     : 7
         Date      : 2008-11-4

as a Proposed Standard.  Substantive comments and statements of support 
for advancing this document should be directed to the mailing list. 
Editorial suggestions can be sent to the document editor.  This last 
call will end on March 16, 2009.

Regards,
Brian & Bob
6MAN co-chairs

---

From: Rémi Denis-Courmont <[email-masked]>
Date: Mon, 02 Mar 2009 16:16:22 +0100

> call will end on March 16, 2009.

Overall, I think this document should go forward.

However, the recommendation part should perhaps be a bit more explicit. I
assume the recipient node should not trash packets with a matching source,
destination and fragment ID *forever*, but rather within a reasonable time
frame.

-- 
Rémi Denis-Courmont

---

From: Suresh Krishnan <[email-masked]>
Date: Thu, 05 Mar 2009 16:32:33 -0500

Hi Remi,
   Thanks you for catching this.

> Overall, I think this document should go forward.

Great.

> destination and fragment ID *forever*, but rather within a reasonable time

Yes. You are right. The text in the draft is misleading. After further 
thought I felt that this text was extraneous anyway and can be safely 
removed. So, I propose the following change to this section.

OLD:
  IPv6 nodes that receive a fragment
    that overlaps with a previously received fragment MUST cease the
    reassembly process and MUST ignore further fragments with the same
    IPv6 Source Address, IPv6 Destination Address and Fragment
    Identification.  It MUST also discard the previously received
    fragments with the same IPv6 Source Address, IPv6 Destination Address
    and Fragment Identification.

NEW:
  IPv6 nodes that receive a fragment
    that overlaps with a previously received fragment MUST cease the
    reassembly process and MUST discard the previously received
    fragments with the same IPv6 Source Address, IPv6 Destination Address
    and Fragment Identification.

My reasoning was that the 60 second reassembly rule of RFC2460 would 
automatically take care of "ignoring" the further fragments coming in 
with the same Fragment Identification. Is this acceptable?

Thanks
Suresh