Subject: [secdir] SECDIR Review draft-ietf-ippm-ioam-flags-06

From: Donald Eastlake <[email-masked]>
Date: Wed, 22 Sep 2021 17:24:04 -0400

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.

The summary of the review is Ready with a minor issue. (really just
capitalization of key words)

Security:

I believe that the theme of the Security Considerations section, that
possible use of the IOAM flags specified in this document could be
used in amplification attacks, is correct and that the Security
Considerations section adequately explores this topic.

Minor:

Section 4.1.1: Both occurrences of "recommended" seem like they should
be in all capital letters.

Section 4.2: Second paragraph, "recommended" should be all capital
letters. Also, this stuff about N seems to be redundantly included in
both 4.1.1 and 4.2 which are adjacent sections. Maybe the second
paragraph in 4.2 could be replaced by a tweaked version of its first
sentence something like: "An IOAM node that supports the reception and
processing of the Loopback flag MUST support the ability to limit the
rate of the looped back packets as discussed in Section 4.1.1.".

Section 5: last paragraph, "It is recommended to use N>100." -> "Using
N>100 is RECOMMENDED."

Nits:

Section 2.2: Suggest adding reference to the Terminology entry for
OAM:  [RFC6291]

Section 4.1: last sentence of 2nd paragraph (first full sentence of
page 5): Somehow "allowing a single data field" does not sound quite
strong enough to me. Suggest "allowing only a single data field" or
"limiting to a single data field" or some other stronger and clearer
wording.

Section 4.1.1: Remove superfluous wording: "It is noted that this
requirement..." -> "This requirement..."
Section 4.1.1: Grammar and incorporating capitalization point from
above: "it is recommended to use N>100." -> "using N>100 is
RECOMMENDED." (and same change in Section 4.2 if Section 4.2 is not
modified as suggested above)

Section 5: third bullet point "one or more IOAM option," -> "one or
more IOAM options," Also, in the same bullet point, remove superfluous
wording "It should be noted that the current..." -> "The current..."

Multiple places "to avoid loading" would be a little better as "to
avoid overloading" or "to avoid excessively loading".

There are almost twice as many authors as the guideline maximum of 5.

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