Hi Linda, Thanks for the review and questions, please find my replies inline: > -----Original Message----- > From: Linda Dunbar via Datatracker <noreply@xxxxxxxx> > Sent: Saturday, February 8, 2025 1:35 PM > To: ops-dir@xxxxxxxx > Cc: draft-ietf-idr-cpr.all@xxxxxxxx; idr@xxxxxxxx; last-call@xxxxxxxx > Subject: Opsdir last call review of draft-ietf-idr-cpr-07 > > Reviewer: Linda Dunbar > Review result: Has Nits > > I have reviewed this document as part of the Ops area directorate's ongoing > effort to review all IETF documents being processed by the IESG. These > comments were written primarily for the benefit of the Ops area directors. > Document editors and WG chairs should treat these comments just like any > other last-call comments. > > The document is written very clear. > However, I have a few questions. Hope the authors can answer: > 1) The draft mentions that color values may need to be mapped differently > across AS boundaries but does not specify how operators should coordinate > color-mapping policies. For example: If AS1 represents "low latency" as color > 10, but AS2 uses color 20 for the same intent, how is policy coordination > ensured? As the ASes are under the same administration or with an operational trust model, they would know each other's color/intent mapping. In this example, AS2 would know that color 10 in AS1 means "low latency" and needs to be mapped to color 20 in AS2. When the ASBR of AS2 receives a CPR route with color from AS1, it would update the color extended community to 20 based on the color mapping policy. > > 2) The draft does not specify how CPR interacts with the BGP Best Path > Selection process when multiple paths exist with different colors. If an AS > receives multiple CPR advertisements for the same prefix but with different > colors, how does the AS decide which path to prefer? Good question, with CPR mechanism, at the prefix originator, each colored prefix is associated with a specific intent (i.e. color). And in each domain, according to the color mapping policy, the same CPR route is always updated with the same color. Thus normally there will never be multiple copies of CPR routes with the same prefix but different color. The case you described is considered as an error which should be logged, and none of these routes should be used. Best regards, Jie > > Thank you very much! > > Linda Dunbar > > -- last-call mailing list -- last-call@xxxxxxxx To unsubscribe send an email to last-call-leave@xxxxxxxx
