Last Call Review of draft-ietf-rtgwg-uloop-delay-08
review-ietf-rtgwg-uloop-delay-08-opsdir-lc-dunbar-2017-10-15-00

I have reviewed this document as part of the Operational directorate's ongoing
effort to review all IETF documents being processed by the IESG.  These
comments were written primarily for the benefit of the operational area
directors. Document editors and WG chairs should treat these comments just like
any other last call comments.

Document: draft-ietf-rtgwg-uloop-delay-08

Reviewer: Linda Dunbar

Review result: Have Questions.

Section 6.1 gives an example of when to use the scheme of the proposed delay:
Traffic from G to F:  G->D->C->E->F. Your document states: When link C-E fails,
if C updates its forwarding entry for F before D, a transient loop occurs. 
Therefore, "For traffic from G to F, C delaying the update of its forwarding
entry to F."

Question:

For reverse traffic, i.e. from F to G, the primary path is F->E->C->D->G
Does it mean that if D updates its forward entry for G before C, a transient
loop occurs? Does D need to delay its forwarding entry to G?   i.e. C delaying
update of its forwarding entry to F, but D delaying update of its forwarding
entry to G. How about to other destinations?

Does it mean that C & D have to delay its forwarding entry based on
destinations?

Thank you very much.

Linda Dunbar