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.   In my view this document is ready.   The document fixes interoperability issues with the definition of previously published IS-IS TLVs. While I am not an IS-IS expert and the document is not meant to be read as a standalone I do not see any security issues raised by the described clarifications.   -- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.