Re: [secdir] secdir re-review of draft-krishnan-v6ops-teredo-update-07

Suresh Krishnan <suresh.krishnan@ericsson.com> Wed, 02 June 2010 05:54 UTC

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Date: Wed, 2 Jun 2010 01:50:12 -0400
From: Suresh Krishnan <suresh.krishnan@ericsson.com>
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Subject: Re: [secdir] secdir re-review of draft-krishnan-v6ops-teredo-update-07
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Hi Tom,
   Thanks again for your comments on the new revision. I will try to 
work out with Russ, David and you as to how to best do this comparison 
and I will update the document after we agree.

Thanks
Suresh

On 10-06-01 06:22 PM, Tom Yu wrote:
> This is a re-review of draft-krishnan-v6ops-teredo-update-07, which I
> previously reviewed in its -03 version.  Most of my concerns from the
> previous review have been adequately addressed.
> 
> I concur with the ballot comment by Russ Housley about quantifying the
> resistance of this randomization scheme to address scanning in
> relation to the general IPv6 address scanning risk.  For example, if
> the attacker knows the Teredo server's IPv4 address and client's
> external IPv4 address but the client's Teredo UDP port number, the
> effective search space after the flag randomization is 28 bits.
> Effective address search spaces for similar scenarios can be computed
> easily.  Explicitly comparing the values in section 2.3 of RFC 5157
> with the search space sizes resulting from implementing the technique
> in this update may be helpful to the reader.