Hi Deborah/Alia, Thanks for the comments. We really need a TE metric that can be used as last resort metric. RFC 5817 is very clear that 0xffffffff is a last-resort metric. Probably prior to 5817, there were no clear statements on The metric 0xffffffff being usable metric and resulted in implementation Differences.
I do see the conflict with RFC 5817 if this draft sets metric to 0xfffffffe. I think all the confusion is not really worth. While deploying feature in this draft operators have to make sure All the head-ends are behaving correctly with respect to 0xffffffff. I’ll change the TE metric to 0xffffffff in the next revision. WG, Let me know in case of any concern. Rgds Shraddha From: Acee Lindem (acee) [mailto:a...@cisco.com] Sent: Thursday, January 25, 2018 9:06 PM To: Alia Atlas <akat...@gmail.com>; Deborah Brungard <db3...@att.com> Cc: The IESG <i...@ietf.org>; OSPF List <ospf@ietf.org>; draft-ietf-ospf-link-overl...@ietf.org; ospf-cha...@ietf.org; TEAS WG (t...@ietf.org) <t...@ietf.org> Subject: Re: Deborah Brungard's Discuss on draft-ietf-ospf-link-overload-13: (with DISCUSS and COMMENT) Hi Alia, From: Alia Atlas <akat...@gmail.com<mailto:akat...@gmail.com>> Date: Thursday, January 25, 2018 at 10:30 AM To: Deborah Brungard <db3...@att.com<mailto:db3...@att.com>> Cc: The IESG <i...@ietf.org<mailto:i...@ietf.org>>, OSPF WG List <ospf@ietf.org<mailto:ospf@ietf.org>>, "draft-ietf-ospf-link-overl...@ietf.org<mailto:draft-ietf-ospf-link-overl...@ietf.org>" <draft-ietf-ospf-link-overl...@ietf.org<mailto:draft-ietf-ospf-link-overl...@ietf.org>>, Acee Lindem <a...@cisco.com<mailto:a...@cisco.com>>, "ospf-cha...@ietf.org<mailto:ospf-cha...@ietf.org>" <ospf-cha...@ietf.org<mailto:ospf-cha...@ietf.org>>, "TEAS WG (t...@ietf.org<mailto:t...@ietf.org>)" <t...@ietf.org<mailto:t...@ietf.org>> Subject: Re: Deborah Brungard's Discuss on draft-ietf-ospf-link-overload-13: (with DISCUSS and COMMENT) More specifically, as Deborah pointed out, in RFC 5817 Section 4.1, it says "Specifically, the node where graceful shutdown of a link is desired originates the TE LSA or IS- IS-LSP containing a Link TLV for the link under graceful shutdown with the Traffic Engineering metric set to 0xffffffff, 0 as unreserved bandwidth. " and draft-ietf-ospf-link-overload-14 conflicts with that by using 0xfffffffe instead. I’ll defer to Shraddha and the other authors on this one. We did discuss the RFC 5817 inconsistency once already and the intension is that TE interface would still be used as a last resort TE interface. Thanks, Acee Regards, Alia On Thu, Jan 25, 2018 at 10:26 AM, Alia Atlas <akat...@gmail.com<mailto:akat...@gmail.com>> wrote: Could a look at the changes in draft-ietf-ospf-link-overload-14 happen? Also, it would be good to get feedback from TEAS on this document and any concerns. Thanks, Alia On Tue, Jan 23, 2018 at 12:01 PM, Deborah Brungard <db3...@att.com<mailto:db3...@att.com>> wrote: Deborah Brungard has entered the following ballot position for draft-ietf-ospf-link-overload-13: Discuss When responding, please keep the subject line intact and reply to all email addresses included in the To and CC lines. (Feel free to cut this introductory paragraph, however.) Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html<https://urldefense.proofpoint.com/v2/url?u=https-3A__www.ietf.org_iesg_statement_discuss-2Dcriteria.html&d=DwMGaQ&c=HAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=NyjLsr7JA7mvpCJa0YmPdVKcmMXJ31bpbBaNqzCNrng&m=HqvwIxIY6w9NAMb9bpYAlqt5wh5HYxoQ3QkWOKcXXCU&s=xuIvfhP39cZHUJrGuga06L6ws5jUz7Qh5bAqTiGFwV4&e=> for more information about IESG DISCUSS and COMMENT positions. The document, along with other ballot positions, can be found here: https://datatracker.ietf.org/doc/draft-ietf-ospf-link-overload/<https://urldefense.proofpoint.com/v2/url?u=https-3A__datatracker.ietf.org_doc_draft-2Dietf-2Dospf-2Dlink-2Doverload_&d=DwMGaQ&c=HAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=NyjLsr7JA7mvpCJa0YmPdVKcmMXJ31bpbBaNqzCNrng&m=HqvwIxIY6w9NAMb9bpYAlqt5wh5HYxoQ3QkWOKcXXCU&s=vOC5CmTSOwCtauM4jMmeswl6tf_g2mYmFi_x07D4sXY&e=> ---------------------------------------------------------------------- DISCUSS: ---------------------------------------------------------------------- This document is defining a MAX-TE-METRIC of 0xfffffffe. But RFC5817 defined 0xffffffff to be used for graceful shutdown. I noted an email exchange between the author and Acee on this where Acee raised the question why RFC5817's value was not used. Shraddha replied "We can if we have the Working Group Consensus". There was no further discussion. This document was not shared with teas which is responsible for TE (or ccamp which was originally responsible for RFC5817). Either this value needs to be changed to RFC5817's value or this TE metric needs to be removed from this document until agreement with TEAS. ---------------------------------------------------------------------- COMMENT: ---------------------------------------------------------------------- I found the title of section 7.2 "Controller Based Traffic Engineering Deployments" confusing as it only is describing a controller controlling a path. It is not "TE" in the IETF sense e.g. TE signaling. It would be much less confusing if say "Controller Based Deployments" and "satisfying the traffic engineering constraints"/s/"satisfying the constraints". Especially as for TE, procedures already do exist. I noted in the introduction you did reference RFC5817 MPLS Graceful Shutdown on the procedures when doing a graceful shutdown of a TE link.
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