Subject: [secdir] Secdir review of draft-ietf-v6ops-reducing-ra-energy-consumption-02

From: Yaron Sheffer <[email-masked]>
Date: Fri, 16 Oct 2015 19:19:43 +0300

I have reviewed this document as part of the security directorate's
ongoing effort to review all IETF documents being processed by the
IESG.
These comments were written primarily for the benefit of the
security
area directors.  Document editors and WG chairs should treat these
comments just like any other last call comments.

This document contains device-side and network-side recommendations
aimed at reducing the number of IPv6 Router Advertisements, so that
battery-powered devices are not badly affected by them. The document
is short and well-written.

Summary

The document is ready to be published, with a few minor issues.

Details

- My main issue with the document is that it describes a situation
that's broken on both the network and the device side. It then
proposes to change both sides, but it seems to me that we are now at
a "local minimum". Given the existing network, there is no
motivation for devices to change. And given the existing devices,
there is no motivation for networks to change. I would suggest to
propose a transition strategy that will get us there without
assuming that all networks and all devices will magically start
doing "the right thing" all at the same time. For example, during
the transition period devices SHOULD allow to configure certain
networks for the old behavior, and other networks for the new one.
Or maybe devices can detect the network's behavior automatically.

- Sec. 5.1 suggests to prefer certain Router Solicitations on the
network side, so I would expect Sec. 5.2. to recommend that devices
should use exactly those Solicitations.

- The term "appropriate countermeasures" is not very useful when
recommending security solutions. Do you have any examples? Router
configurations? IPS devices? Legal actions? :-)

- Can you add something about whether your proposal increases or
decreases the risk of malicious hosts bricking a device (or a
router?) by sending a RA with incorrect information?

Thanks,

Yaron