Last Call Review of draft-ietf-bess-evpn-proxy-arp-nd-09
review-ietf-bess-evpn-proxy-arp-nd-09-rtgdir-lc-singh-2020-12-22-00

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-proxy-arp-nd
Reviewer: Ravi Singh
Review Date: 21 Dec 2020
Intended Status: Standards track (as listed on the draft)

Summary:

This document is basically ready for publication, but has nits that should be
considered prior to publication.

Comments:

The draft is generally well written and easy to understand.
It basically is a description to explain how ARP, ND, EVPN should work together
to reduce forwarding of ARP queries and/or NS messages, in an EVPN deployment,
by the use of gratuitous ARP/ND. The abstract, though, could be made more
direct by stating as such.

Major Issues: none found.

Minor Issues: none found.

Nits:
1. Figure 1: please show which device owns IP3, for more clarity.

2.      Section 4.6 (a):
        a. "       IP moves before the timer expires (default value of N=5), it
       concludes that a duplicate IP situation has occurred.  An IP move". It
       would be nice to elaborate on why the default value of "5" is
       recommended. Why not 1? Too much thrashing? However, for the cases where
       there is no thrashing, having a value of 5 as default slows the DAD
       procedure. Any recommendation on how to address that?
        b.      Minor typo: "       owner and spoofer keep replying to the
        CONFIRM message, the PE
       will detect the duplicate IP within the M timer:" ->
                "      owner and spoofer keep replying to the CONFIRM message,
                the PE
       will detect the duplicate IP within the M-second timer:"

3. Biggest nit: the draft does not really specify any new messaging formats or
any new fields. It is basically saying how the existing ARP, ND, EVPN
messaging/machinery (should) work together to achieve flooding-minimization of
ARP/ND queries in EVPN. Given the foregoing, it is not clear to me if the draft
really should be considered "standards track" instead of "informational". The
chairs are requested to evaluate that.

Best regards
Ravi