Last Call Review of draft-ietf-pce-inter-layer-ext-12
review-ietf-pce-inter-layer-ext-12-secdir-lc-emery-2017-03-09-00

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 draft discusses extensions to the Path Computation Element
communication Protocol (PCEP) that allows network path information to
passed through multiple technology layers.  This data can be used to
optimize network utilization by accounting for all of the layers in the
stack instead of individual characteristics.

The security considerations section does exist and states that
controlling networks from inter-layer information does present security
threats.  The section goes on to state that a security threat is also
introduced if a PCE is given full visibility of multi-layer traffic
engineering information.  Could you please expand on the threat
specifically with visibility?  To mitigate against such attacks the draft
suggests the usage of the Path-Key-based (of no relation to a cryptographic
key) mechanism, as described in RFC 5520.  I agree with this assertion, or
at least with the first threat outlined.

General comments:

None.

Editorial comments:

None.  Thanks!

Shawn.
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