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-ospf-ospfv3-segment-routing-extensions-17.txt Reviewer: Tomonori Takeda Review Date: Nov 14th, 2018 IETF LC End Date: Nov 16th, 2018 Intended Status: Proposed Standard o Summary: This document is basically ready for publication, but has nits that should be considered prior to publication. o Comments: This document defines OSPFv3 extensions for Segment Routing with MPLS data plane. This document is mostly ready, but further clarification would be good for better understanding of the protocol definitions (see below). This document is well aligned with a related document draft-ietf-ospf-segment-routing-extensions. o Major Issues: None o Minor Issues: 1) Flooding Scope of SR-Algorithm TLV In Section 4.1, it says: "If the SR-Algorithm TLV appears in multiple OSPFv3 Router Information Opaque LSAs that have different flooding scopes, the SR-Algorithm TLV in the OSPFv3 Router Information Opaque LSA with the area-scoped flooding scope MUST be used." At the same time, it say: "For the purpose of SR-Algorithm TLV advertisement, area- scoped flooding is REQUIRED." So, does it mean a) a router MUST use area-scoped flooding for sending, and b) a router MUST support different flooding scopes for receiving? 2) LSA Type for OSPFv3 Extended Prefix Range TLV In Section 5, it defines IA-Flag. It is not clear how this relates to LSA type. Do we simply ignore LSA type being used to carry OSPFv3 Extended Prefix Range TLV? 3) Meaning of SID/Index/Label in Prefix SID Sub-TLV In Section 6, it says: "SID/Index/Label: According to the V and L flags, it contains either: A 32-bit index defining the offset in the SID/Label space advertised by this router. A 24-bit label where the 20 rightmost bits are used for encoding the label value." I understand how V Flag relates to this selection, but it is not clear how L flag relates to this selection. o Nits None Thanks, Tomonori Takeda