Subject: [Gen-art] Gen-ART Telechat review of draft-ietf-v6ops-pmtud-ecmp-problem-04

From: Paul Kyzivat <[email-masked]>
Date: Fri, 9 Oct 2015 11:40:03 -0400

I am the assigned Gen-ART reviewer for this draft. The General Area 
Review Team (Gen-ART) reviews all IETF documents being processed by the 
IESG for the IETF Chair. Please wait for direction from your document 
shepherd or AD before posting a new version of the draft. For more 
information, please see the FAQ at <​ 
http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.

[Note: I received no response to my LC comments. Reviewing the message I 
sent, I wonder if it perhaps was not delivered. The following comments 
are a duplicate of what I sent as LC comments.]

Summary: This draft is on the right track but has open issues, described 
in the review.

Major Issues: NONE

Minor Issues:

It would be helpful if this draft described its intended target 
audience. It would also benefit from having additional references 
providing background context for the substance of the draft.

In particular, "ECMP" and "PMTUD" are used extensively, in the text and 
even the title of the draft. While these acronyms are expanded in the 
text, there are no references to definitions of them.

I sought out references for ECMP. The ones I found are RFC2991 and 
RFC2992, which are old. Is there a more recent analysis that ought to be 
considered? It seems that the problem at hand comes when using ECMP for 
load balancing across multiple servers. Is there some reference that 
talks about that? (RFCs 2991 and 2992 are more general - they could 
apply in other contexts and don't mention this use.)

The single reference in the document is to RFC4821. Is it the proper 
reference for PMTUD? It seems to be closely related, but it seems to be 
more specialized.

In the Security Considerations section a possible attack is identified, 
and a mitigation described. But then a seemingly serious drawback to the 
mitigation is also described. I think this bears more discussion.

	Thanks,
	Paul

---

From: Jari Arkko <[email-masked]>
Date: Thu, 15 Oct 2015 10:32:51 +0300

Thanks for your review, Paul.  I agree that a reference would be nice.

Jari

---

From: Benoit Claise <[email-masked]>
Date: Thu, 15 Oct 2015 09:54:36 +0200

Thanks Paul.

Regards, B.
> Review Team (Gen-ART) reviews all IETF documents being processed by 
> the IESG for the IETF Chair. Please wait for direction from your 
> document shepherd or AD before posting a new version of the draft. For 
> more information, please see the FAQ at <​ 
> [Note: I received no response to my LC comments. Reviewing the message 
> I sent, I wonder if it perhaps was not delivered. The following 
> comments are a duplicate of what I sent as LC comments.]
>
> Summary: This draft is on the right track but has open issues, 
> described in the review.
>
> Major Issues: NONE
>
> Minor Issues:
>
> In particular, "ECMP" and "PMTUD" are used extensively, in the text 
> and even the title of the draft. While these acronyms are expanded in 
> the text, there are no references to definitions of them.
>
> RFC2992, which are old. Is there a more recent analysis that ought to 
> be considered? It seems that the problem at hand comes when using ECMP 
> for load balancing across multiple servers. Is there some reference 
> that talks about that? (RFCs 2991 and 2992 are more general - they 
> could apply in other contexts and don't mention this use.)
>
> reference for PMTUD? It seems to be closely related, but it seems to 
> be more specialized.
>
> In the Security Considerations section a possible attack is 
> identified, and a mitigation described. But then a seemingly serious 
> drawback to the mitigation is also described. I think this bears more 
> discussion.
>
>     Thanks,
>     Paul
>
> .
>