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-bess-evpn-overlay-10.txt Reviewer: Lou Berger Review Date: Jan 9, 2018 IETF LC End Date: date-if-known Intended Status: Standards Track Summary: I have some minor concerns about this document that I think should be resolved before publication. Comments: To me the document reads more like an applicability statement than a PS.  I think a few things can and should be done to the document to clean this up.  Some are trivial, some may take more thought.  The core issues are related to (a) detecting/handling configuration mismatches and (b) definition of support for multiple encapsulation types.  I suspect all raised issues can be addressed via documentation changes. Major Issues: Minor Issues: - The document defines a number of deployment options that are not compatible, e.g., section 5.1.2 options 1 and 2, or allowing for "locally configured encapsulation".  It would be good  if the document should explain how such mismatches can be detected by an implementation or in operation and addressed.  If an option can be eliminated, such as configured encapsulation, this should be considered. - The approach taken in the document is clearly applicable to multiple tunneling technologies, and mentioning this is certainly appropriate, but the document leaves some aspects unsaid (and open to interpretation) for encapsulations other than VXLAN.  The scope of the document states that vxlan, nvgre and MPLSoGRE encapsulation are fully supported by the document, but full specification seems to only be present for the first.  For example, section 5.1 references multiple encapsulation technologies, but only defines mechanisms relative to VXLAN (VNIs).  Adding specific procedures for each encapsulation type would make the required mechanisms unambiguous, but this is certainly not the only way to ensure each is fully documented and multiple independent interoperable implementations will be possible. - Section 5.1.2.1 should cover how 4 byte ASes are to be handled Nits: - Lowercase "should" is used in a some places where it looks like "SHOULD" be used.  In general it appears that lowercase was used when referring to requirements defined in other documents.  Upper case is still appropriate in such cases. - Some terms are used without references on their first use.