Subject: [RTG-DIR] RtgDir review: draft-ietf-bess-evpn-prefix-advertisement-10

From: Geoff Huston <[email-masked]>
Date: Thu, 12 Apr 2018 10:47:19 +1000

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-bess-evpn-prefix-advertisement-10.txt
Reviewer: Geoff Huston
Review Date: 12 April 2018
IETF LC End Date: not known
Intended Status: Standards Tract

Summary: 

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

Comments:

Major Issues:

No major issues found.

Minor Issues:

The Introduction (section 2) should preceded the Terminology and all be placed in Section 1. Sections 2.1 and 2.2 appear to be a Problem Statement and should be the content of Section 2. Problem Statement.
 
The Terminology appears to include a mix of conventional acronym expansion which could easily be dealt with by explicit expansion on first use. (for example. the text contains "If the term Tenant System (TS) is used..." and there is probably no need to explicitly call out this acronym in a terminology section.)

There is a phrase in the Introduction that seems out of place: "Once the need for a new EVPN route type is justified, ...". I suggest dropping the phrase on the assumption that Sections 2.1 and 2.2 have indeed justified this problem and the proposed solution.

I am confused between the term "IP address length (IPL)" and "IP Prefix Length" - I an unsure if IPL is an Address family Identifier to distinguish between IPv4 and IPv6 addresses or some other term. Perhaps the authors may want to use more conventional terms when appropriate, such as “AFI" rather than “IPL” if that is really the underlying meaning of this field.

In Figure 3 IP Prefix Route Type, why is an Address Family Identifier missing from the data structure?

I would not call myself an expert in the area of intra-subnet connectivity in an MPLS and/or NVO-based networks, so I am not in a good position to comment on the technical quality of the specification in this draft. The material is dense, and it is unclear to me if the textual-based description of handling actions is complete. It is also unclear to me if the use cases sslected in this draft are inclusive or just represent some random selection of uses cases from a far larger pool of potential use cases.