[secdir] SecDir review of draft-ietf-v6ops-64share-09

[Yaron Sheffer <[e-mail]>]

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 describes two options of providing hosts behind a 3GPP UE 
(e.g., cellular router) with an IPv6 network prefix, in networks that do 
not support IPv6 prefix delegation. The document is explicitly 
non-normative.

Summary

The document is ready to progress.

Details

- I don't understand why the first scenario (sec. 4.2) is even useful, 
i.e. why allocate the /64 to the LAN (and not just settle for a 
link-local prefix) when the UE does not have an address on the 3GPP 
link, and so cannot route traffic to the Internet?

- Despite the non-normative status of the document, I think the security 
considerations deserve stronger wording. I suggest to replace "shall be 
considered" by "SHOULD be applied".

- I would suggest that the security considerations also mention the 
privacy implications of having a (typically) small number of devices, 
all within a single unchanging network prefix. I *believe* this is 
behind the discussion of RFC 4941 is Sec. 4.3, but I would rather have 
the threat spelled out.

Thanks,
      Yaron