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 with the intent of improving security requirements and considerations in IETF drafts.  Comments not addressed in last call may be included in AD reviews during the IESG review.  Document editors and WG chairs should treat these comments just like any other last call comments.

This document describes a historic protocol whose design falls far short of modern IETF standards. Its myriad issues are well-described in the Security Considerations section.

There has been some debate as to whether the appropriate status for this document is Historic or Informational. I believe the currently-intended Historic status is more appropriate. The argument I have heard repeatedly in favor of Informational status is that it is not appropriate to classify a protocol as Historic until a better alternative exists with a published specification. I believe that better alternative exists, which is to have no standard at all. It's perfectly fine for NTP monitoring and management protocols to be vendor-specific. In virtually all legitimate uses ("legitimate" so as to exclude RDoS attacks), both sides of the protocol run on systems managed by the same organization and the need for vendor-specific tools is not a practical issue. Lack of standardization is the already the status quo, since there are many widely-used NTP implementations out there but only the Network Time Foundation implementation and its derivatives (such as NTPsec) support this protocol. I know of nobody who has ever been inconvenienced by this; standardization is a solution in search of a problem.