Hi all: I have reviewed this document as part of the Operational directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the operational area directors. Document editors and WG chairs should treat these comments just like any other last call comments. Overall, it seems fine to me. Abstract: "This document defines Extended Sequence number TLV to protect Intermediate System to Intermediate System (IS-IS) PDUs from replay attacks." Draft addresses Security concerns raised by the use of IS-IS in Data Centre environments, and by the use of SDN in Data Centres. "This document defines Extended Sequence number (ESN) TLV to protect Intermediate System to Intermediate System (IS-IS) PDUs from replay attacks." I presume that the ESSN will be given a random (but non-zero) when the router boots up, then increments from there? This is covered in detail in Appendix A, but perhaps a forward reference to that in section 3 would be helpful. Section 5 on Backward Compatibility and Deployment seems clear to me, and should help Operators to use this new feature. Cheers, Nevil Co-chair, EMAN WG -- --------------------------------------------------------------------- Nevil Brownlee Computer Science Department | ITS Phone: +64 9 373 7599 x88941 The University of Auckland FAX: +64 9 373 7453 Private Bag 92019, Auckland 1142, New Zealand