draft-ietf-rtgwg-mrt-frr-algorithm - some comments

Stewart Bryant <stewart.bryant@gmail.com> Wed, 09 December 2015 11:33 UTC

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From: Stewart Bryant <stewart.bryant@gmail.com>
To: draft-ietf-rtgwg-mrt-frr-algorithm@tools.ietf.org, "rtgwg@ietf.org" <rtgwg@ietf.org>, "rtgwg-chairs@tools.ietf.org" <rtgwg-chairs@tools.ietf.org>
Subject: draft-ietf-rtgwg-mrt-frr-algorithm - some comments
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Date: Wed, 09 Dec 2015 11:33:36 +0000
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Hi,

I am sorry for the late comments

I have looked at the algorithm draft and have a some top level
concerns.

Firstly you have the sections that describe the operation in detail
and the python code both as normative. That is always a dangerous
thing to do since it is not clear which has priority in the
event of a difference.

I am concerned that the algorithm, which can stand on it's own
right and a comparison with other methods is included in this
text. I think that the comparison text from this draft and from
the architecture draft should be put into a single comprehensive
evaluation draft.

Again I am concerned about the assertion of completeness, since it
is complete only against a number of unstated constraints.

Finally the authors have clearly copied the security section from
the architecture draft. Whilst I am sure that the algorithm has
no security concerns per se, that is only because it is placed
in an operational context by code that does input parameter
filtering and an operating system that ensures it executes
correctly. What I would expect from a security analysis was
guidance to the implementers of any particular fragility in
the algorithm that they needed to consider (there may of
course be none).

- Stewart