Last Call Review of draft-ietf-bess-multicast-damping-04

Request Review of draft-ietf-bess-multicast-damping
Requested rev. no specific revision (document currently at 06)
Type Last Call Review
Team Security Area Directorate (secdir)
Deadline 2016-05-03
Requested 2016-03-23
Authors Thomas Morin, Stephane Litkowski, Keyur Patel, Zhaohui Zhang, Robert Kebler, Jeffrey Haas
Draft last updated 2016-04-28
Completed reviews Genart Last Call review of -04 by Joel Halpern (diff)
Secdir Last Call review of -04 by Donald Eastlake (diff)
Opsdir Last Call review of -04 by Bert Wijnen (diff)
Assignment Reviewer Donald Eastlake
State Completed
Review review-ietf-bess-multicast-damping-04-secdir-lc-eastlake-2016-04-28
Reviewed rev. 04 (document currently at 06)
Review result Has Nits
Review completed: 2016-04-28


I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG.  Document editors and WG chairs should treat these comments just like any other last call comments.

This document describes procedures for damping multicast virtual private network routing state changes to control the effect, particularly the control plane load, of the churn due to the dynamic multicast group membership in customer sites.


Overall, I think it is ready with nits but my confidence in that assessment is not very high.

The feature specified in this document is aimed at limiting one type of denial of service, or at least at interference to some users by others: denial or interference due to excessive control plane traffic due to a high rate of multicast group membership change. Still, it makes me a bit queasy that the document has not one word, even by reference, about security for the setting or changing of the parameters used at a node in the damping algorithm. I suppose it is reasonable that it doesn't talk about how any of the control messages involved are protected or authenticated since the document is just about suppressing such messages...

The Security Considerations section has a reasonable discussion of how and to what extent the mechanisms specified provide the services claimed.

Page 15, Section 9 (Security Considerations), 1st paragraph starting on this page: There are a number of things wrong with the following sentence:

          Note well that the two
   mechanism may interact: state for which Prune has been requested may
   still remain taken into account for some time if damping has been
   triggered and hence result in otherwise acceptable new state from
   being successfully created.

I would guess it should be "result in preventing otherwise" or should end with "state not being successfully created". Here is a suggested replacement:

          The two mechanisms may interact as follows: i

f damping has

   been triggered, 

state for which 

Prune has been requested may remain

   and still be taken into account 

for some time

 resulting in an

   otherwise acceptable new state not

 being created.


This document is very heavy with acronymic jargon with no expansion or definition in this document. However, most of it is defined in other RFCs that are referenced.

Although I am willing to accept that it is just a matter of style, this document has lots of extra words that add nothing but verbosity. Things that could be completely dropped with no loss, like starting a sentence with "Additionally, it is worth nothing that ...". If it wasn't worth noting, it presumably wouldn't be in the document.

Page 4, Section 3, 3rd paragraph: "...this technique will allow to meet the goals..." -> "...this technique will meet the goals..."

Page 12, Section 7.2: "More specifically it is RECOMMENDED to complement the existing ... (e.g. MRIB states): ..." -> "Complementing the existing ... (e.g. MRIB states) is RECOMMENDED: ..."

Page 13, Section 7.3, 2nd paragraph: What does "dimentioning" mean? Also "...state churn to go beyond what..." -> "...state churn going beyond what..."

Page 14, Section 9, 3rd paragraph: The word "shall" is used. While not capitalized, this word sounds quite mandatory to me but it is not used in a mandatory requirement context... I suggest "shall rely upon" -> "relies on".

Page 15, near the top: "should rely upon already" -> "should use already"

Finally, while I understand that others have a different opinion, I find it objectionable that not a single first page author is willing to list a telephone number of any sort in the Authors' Addresses section. To my mind, this sort of corner cutting does not speak well for the document.




 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)

 155 Beaver Street, Milford, MA 01757 USA


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