Hello, I have been selected as the Routing Directorate reviewer for this draft. The Routing Directorate seeks to review all routing or routing-related drafts as they pass through IETF last call and IESG review, and sometimes on special request. The purpose of the review is to provide assistance to the Routing ADs. For more information about the Routing Directorate, please see ​http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir Although these comments are primarily for the use of the Routing ADs, it would be helpful if you could consider them along with any other IETF Last Call comments that you receive, and strive to resolve them through discussion or by updating the draft. Document: draft-ietf-idr-flow-spec-v6-17 Reviewer: Jon Hardwick Review Date: 21 Oct 2020 IETF LC End Date: 21 Oct 2020 Intended Status: Standards Track Summary: I have some minor concerns (questions, really) about this document that I think should be resolved before publication. Comments: Overall a well written and easy-to-understand draft. Thank you! Major issues: None. Minor issues: Section 3.6 I note that this is consistent with rfc5575bis, but it left me with several questions. What is an implementation to do if contradictory bits are set in the same bitmask? (IsF & FF)? (FF & LF)? Same question if contradictory bits are set in successive bitmasks and the “AND” bit is set in bitmask_op? What is the effect of setting / clearing the “match” bit in bitmask_op? Section 3.3 “Type 3 component values SHOULD be encoded as single octet” – why not a MUST? Nits: Section 3.1 Suggest rewording “of N first bits of the address” -> “the first N bits of the address” I find the “length” field oddly named. I misunderstood it at first as the length of the pattern. I think “end_offset” might have been a better choice. Not a big deal though.