Subject: [RTG-DIR] RtgDir review: draft-ietf-trill-directory-assist-mechanisms​-03.txt

From: "Bocci, Matthew (Matthew)" <[email-masked]>
Date: Fri, 31 Jul 2015 14:06:04 +0000

Hello,

I have been selected as the Routing Directorate reviewer for this draft.
The Routing Directorate seeks to review all routing or routing-related
drafts as they pass through IETF last call and IESG review, and
sometimes on special request. The purpose of the review is to provide
assistance to the Routing ADs. For more information about the Routing
Directorate, please see
​http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir

Although these comments are primarily for the use of the Routing ADs, it
would be helpful if you could consider them along with any other IETF
Last Call comments that you receive, and strive to resolve them through
discussion or by updating the draft.

Document: draft-ietf-trill-directory-assist-mechanisms​-03.txt
Reviewer: Matthew Bocci
Review Date: July 2015
IETF LC End Date: Unknown
Intended Status: Proposed Standard

Summary:
I have some minor concerns about this
document that I think should be resolved before publication.

Comments:

The draft is mostly ready for publication, but I have some comments related to
which procedures are mandatory to implement, and which are optional (see minor
issues below). I've flagged this because in my experience
it is very important for an RFC to be crystal clear about what is mandatory for
successful interoperability.

Major Issues:

No major issues.

Minor Issues:

In general, it is very unclear if it is mandatory to implement both push and pull,
or if it is adequate to just implement one or the other. I appreciate that a hybrid
mode is possible, in which case an implementation would need to support both, but
this is only described at the end in section 4, almost as an afterthought. It would
be much better if the draft could be clear up-front which is the mandatory (default)
mode, or if both must be implemented if the expectation is that the default operating
model is hybrid.

Section: "1. Introduction"
1st Paragraph: Last sentence
"These mechanisms are optional to implement."
This statement seems redundant, since technically the whole RFC is optional
unless another RFC makes a normative reference to it :) I think you should either
remove this statement, or use it to clarify which modes are optional and which are
mandatory.

Pg14:
"If information previously
   pulled is about to expire, a TRILL switch MAY try to refresh it by
   issuing a new pull request but, to avoid unnecessary requests, SHOULD
   NOT do so if it has not been recently used."

Can you give more information on what you mean by "recently"? Some non-normative
guidance might be helpful to prevent wildly differing or unpredictable behaviours
in a multi-vendor deployment.

Nits:

- There are a few uncommon acronyms. Please expand all acronyms on first use.
- Pg4 s/MacDA/MAC DA
- Pg8 s/angel bracket/angle bracket