Hello,

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.

Summary: Ready

I have no comment regarding the security part. Most issues seem fairly classic
when dealing with BGP peering and the Security Considerations section reminds
it's the responsibility of the network operator to guarranty that traffic is
restricted to trusted domain/nodes. I don't know the domain but it seems 
reasonable.

Otherwise, a minor comment.
Section 2.4.1: I suggest being a bit more informative when describing Type and Length fields (this is the first mention of the packet format):
>   o  Type: 12
>   o  Length: 6.

There's no explanation and no unit.
As I understand, 12 is a reserved value for a "Preference Sub-TLV", say it, and Length is 6 bytes long, encompassing the Flags, RESERVED, and Preference fields, say that too (at least the 1st time).

Cheers,

Vincent