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-sidrops-ov-egress
Reviewer: Yingzhen Qu
Review Date: March 17th, 2020
Intended Status: Standards Track

Summary:

This document is near ready for publication. It has some issues that should be at least considered prior to publication.

This is a very concise document, and the goal is to provide clarifications on BGP origin validation when egress policies are used, especially when the effective origin AS is different from the origin AS. 

Major Issues:
No major issue found.

Minor Issues:

I’d suggest to add a couple of examples to help understanding the document.

In section 4: 
“Therefore it SHOULD be possible to specify an origin validation
 policy which MUST BE run after such non-deterministic policies.”

My understanding is the origin AS might have been changed by egress policy, and in some complicated case, the effective origin AS is hard to predict, and an origin validation policy MUST be run. But how should this “possible” policy be specified?

In section4:
“An operator SHOULD be able to list what announcements are not sent to
A peer because they were marked Invalid, as long as the router still
has them in memory.”

Is this the list of routes that were marked Invalid before egress policy? Routes that were validated using the origin AS.

Nits:
In section 4: 
“Therefore it SHOULD be possible to specify an origin validation
 policy which MUST BE run after such non-deterministic policies.”

“MUST” instead of “MUST BE”?