[secdir] Secdir review of draft-ietf-pim-drlb-13

[Carl Wallace <[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 defines an extension to the PIM-SM protocol to allow some responsibilities of is Designated Router to be distributed amongst a set of routers instead of the router elected as DR. 

The document is well written and has clear examples. The security considerations references those of the DR as applicable to the new mechanism. This seems fine.  One minor comment, the last sentence in the operational considerations section seemed odd to me. It wasn't clear to me why migration between different hash algorithms is not considered in this document (or why this is much different from changes in DR priority, which is also required to be considered as a GDR candidate). 

The document is ready to my eye.