I would like to see actual textual updates in the form of new revisions for the clarifications that have been proposed for both draft-ietf-ospf-segment-routing-extensions and draft-ietf-spring-segment-routing so that we know exactly what text we are agreeing on.
Chris -----Original Message----- From: Acee Lindem (acee) [mailto:[email protected]] Sent: Thursday, September 29, 2016 10:50 AM To: Chris Bowers <[email protected]>; Les Ginsberg (ginsberg) <[email protected]>; Peter Psenak (ppsenak) <[email protected]>; OSPF List <[email protected]> Subject: Re: [OSPF] OSPFv2 SR draft Speaking as WG Co-Chair: Hi Chris, Les, Peter, So, is there anything preventing us from requesting publication of the OSPFv2 Segment Routing draft? Thanks, Acee On 8/25/16, 11:00 AM, "OSPF on behalf of Chris Bowers" <[email protected] on behalf of [email protected]> wrote: >Les and Peter, > >I have also been pursuing the approach you suggest. > >The following request to clarify draft-ietf-spring-segment-routing-09 >on this topic was sent on Aug. 3rd. > >https://www.ietf.org/mail-archive/web/spring/current/msg02273.html > >Hopefully, we can get closure on these clarifications soon. > >Thanks, >Chris > > >-----Original Message----- >From: Les Ginsberg (ginsberg) [mailto:[email protected]] >Sent: Thursday, August 25, 2016 9:32 AM >To: Peter Psenak (ppsenak) <[email protected]>; Chris Bowers ><[email protected]>; OSPF List <[email protected]> >Subject: RE: [OSPF] OSPFv2 SR draft > >Chris/Peter - > >> -----Original Message----- >> From: OSPF [mailto:[email protected]] On Behalf Of Peter Psenak >> (ppsenak) >> Sent: Thursday, August 25, 2016 1:45 AM >> To: Chris Bowers; OSPF List >> Subject: Re: [OSPF] OSPFv2 SR draft >> >> Hi Chris, >> >> On 24/08/16 20:31 , Chris Bowers wrote: >> > Peter, >> > >> > The text that you propose corresponds to part of the text that I >> > proposed, >> and it seems good to me. >> > >> > However, the last sentence of the text that I proposed in not >>addressed. >> > ------ >> > If router B does not advertise the >> > SR-Algorithm TLV for algorithm X, then other routers should not >> > forward traffic destined for a prefix-SID for algorithm X >> > advertised by some router D using a path that would require router >> > B to forward traffic using algorithm X. >> > ------ >> > Is this an oversight? >> >> not that I disagree with the statement that you want to add. >> >> The question is whether that belongs to the IGP SR draft, or whether >> that should be specified in a different draft. >> >> There is already some text regarding the forwarding for a SR >> algorithm in draft-ietf-spring-segment-routing section 3.2.1., which >> may not be aligned with what you have in mind: >> >> "The ingress node of an SR domain validates that the path to a >>prefix, >> advertised with a given algorithm, includes nodes all supporting the >> advertised algorithm. In other words, when computing paths for a >> given algorithm, the transit nodes MUST compute the algorithm X on >> the IGP topology, regardless of the support of the algorithm X by >>the >> nodes in that topology. As a consequence, if a node on the path >>does >> not support algorithm X, the IGP-Prefix segment will be interrupted >> and will drop packet on that node. It's the responsibility of the >> ingress node using a segment to check that all downstream nodes >> support the algorithm of the segment." >> >> Maybe we should add/modify the text in >>draft-ietf-spring-segment-routing section 3.2.1, rather then adding >>anything to the OSPF/ISIS SR drafts. >> >[Les:] I strongly agree with this approach. If one wants to understand >how the MPLS dataplane works with SR then the following documents are >relevant: > >https://www.ietf.org/id/draft-ietf-spring-segment-routing-09.txt >https://www.ietf.org/id/draft-ietf-spring-segment-routing-mpls-05.txt >https://www.ietf.org/id/draft-ietf-spring-segment-routing-ldp-interop-0 >4.t >xt > >References to these documents can be included in the IGP drafts - but >we should not try to repurpose the IGP drafts to cover material which >is covered far more completely in the above drafts. > >If you feel there is something which needs to be added/revised to any >of the above drafts to more accurately explain algorithm specific >forwarding please make the comment in the context of one of those drafts. > > Les > >> thanks, >> Peter >> >> > >> > Thanks, >> > Chris >> > >> > >> > -----Original Message----- >> > From: Peter Psenak [mailto:[email protected]] >> > Sent: Monday, August 22, 2016 2:32 AM >> > To: Chris Bowers <[email protected]>; OSPF List <[email protected]> >> > Subject: Re: [OSPF] OSPFv2 SR draft >> > >> > Chris, >> > >> > what about this to be added in the Section 3.1: >> > >> > >> > "A router receiving a Prefix-SID (defined in section 5) from a >> > remote node >> and with an SR algorithm value that such remote node has not >>advertised in the SR-Algorithm sub-TLV MUST ignore the Prefix-SID >>sub-TLV." >> > >> > thanks, >> > Peter >> > >> > >> > On 19/08/16 23:33 , Chris Bowers wrote: >> >> Peter, >> >> >> >> Please share the updated text that you plan to use with the WG, >> >> since this >> is a reasonably significant clarification. >> >> >> >> Thanks, >> >> Chris >> >> >> >> -----Original Message----- >> >> From: Peter Psenak [mailto:[email protected]] >> >> Sent: Tuesday, August 16, 2016 10:02 AM >> >> To: Chris Bowers <[email protected]>; OSPF List <[email protected]> >> >> Subject: Re: [OSPF] OSPFv2 SR draft >> >> >> >> Hi Chris, >> >> >> >> I'll update the draft along those lines. >> >> >> >> thanks, >> >> Peter >> >> >> >> >> >> On 16/08/16 16:02 , Chris Bowers wrote: >> >>> Peter, >> >>> >> >>> I suggest changing the paragraph to read as below to make this >>clearer. >> >>> >> >>> ===== >> >>> The SR-Algorithm Sub-TLV is optional. It MAY only be >>advertised once >> >>> in the Router Information Opaque LSA. If the SID/Label >> >>> Range >>TLV, as >> >>> defined in Section 3.2, is advertised, then the >> >>> SR-Algorithm >>TLV MUST >> >>> also be advertised. If a router C advertises a Prefix-SID >> >>> sub-TLV for >> algorithm X >> >>> but does not advertise the SR-Algorithm Sub-TLV with >> >>> algorithm X, >> then >> >>> a router receiving that advertisement MUST ignore the >>Prefix-SID >> >>> advertisement from router C. If router B does not >> >>> advertise >>the >> >>> SR-Algorithm TLV for algorithm X, then other routers should >>not >> >>> forward traffic destined for a prefix-SID for algorithm X >>advertised by >> >>> some router D using a path that would require router B to >> >>> forward >> traffic using >> >>> algorithm X. >> >>> ===== >> >>> >> >>> Thanks, >> >>> Chris >> >>> >> >>> >> >>> >> >>> -----Original Message----- >> >>> From: Peter Psenak [mailto:[email protected]] >> >>> Sent: Monday, August 15, 2016 6:40 AM >> >>> To: Chris Bowers <[email protected]>; OSPF List <[email protected]> >> >>> Subject: Re: [OSPF] OSPFv2 SR draft >> >>> >> >>> Hi Chris, >> >>> >> >>> sorry for the delay, I was on PTO during last two weeks. >> >>> Please see inline: >> >>> >> >>> On 03/08/16 16:45 , Chris Bowers wrote: >> >>>> Peter, >> >>>> >> >>>> Taking a looking at the whole paragraph into this sentence was >> >>>> added, I am not sure how to interpret it. >> >>>> >> >>>> The SR-Algorithm Sub-TLV is optional. It MAY only be >> >>>> advertised >> once >> >>>> in the Router Information Opaque LSA. If the SID/Label >> >>>> Range TLV, >> as >> >>>> defined in Section 3.2, is advertised, then the >> >>>> SR-Algorithm TLV >> MUST >> >>>> also be advertised. If the SR-Algorithm TLV is not >>advertised by the >> >>>> node, such node is considered as not being segment >> >>>> routing >> capable. >> >>>> >> >>>> Is this sentence intended to imply that if a router does not >> >>>> advertise the SR-Algorithm TLV including algorithm X, then any >> >>>> prefix-SIDs for algorithm X advertised by that router will be >> >>>> ignored by >> other routers? >> >>> >> >>> in OSPF we do not have the SR capability TLV. We use SR-Algorithm >> >>> TLV for that purpose. So if a router does not advertise the >> >>> SR-Algorithm TLV for algorithm X, other routers should not send >> >>> any SR traffic using SIDs that were advertised for algorithm X. >> >>> >> >>> If the router does not advertise any SR Algorithm TLV, then the >> >>> node is not SR capable and no SR traffic should be forwarded to >>such a node. >> >>> >> >>> thanks, >> >>> Peter >> >>> >> >>> >> >>>> >> >>>> If this is the intention, then it would be better to state is >> >>>> more >> explicitly. >> >>>> >> >>>> If not, then the intended meaning should be clarified. >> >>>> >> >>>> Thanks, >> >>>> Chris >> >>>> >> >>>> >> >>>> -----Original Message----- >> >>>> From: OSPF [mailto:[email protected]] On Behalf Of Peter >> >>>> Psenak >> >>>> Sent: Friday, July 22, 2016 3:30 AM >> >>>> To: OSPF List <[email protected]> >> >>>> Subject: [OSPF] OSPFv2 SR draft >> >>>> >> >>>> Hi All, >> >>>> >> >>>> following text has been added in the latest revision of the >> >>>> OSPFv2 SR draft, section 3.1. >> >>>> >> >>>> "If the SR-Algorithm TLV is not advertised by node, such node is >> >>>> considered as not being segment routing capable." >> >>>> >> >>>> Please let us know if there are any concerns regarding this >>addition. >> >>>> >> >>>> thanks, >> >>>> Peter >> >>>> >> >>>> _______________________________________________ >> >>>> OSPF mailing list >> >>>> [email protected] >> >>>> https://www.ietf.org/mailman/listinfo/ospf >> >>>> . >> >>>> >> >>> >> >>> . >> >>> >> >> >> >> . >> >> >> > >> > . >> > >> >> _______________________________________________ >> OSPF mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/ospf > >_______________________________________________ >OSPF mailing list >[email protected] >https://www.ietf.org/mailman/listinfo/ospf _______________________________________________ OSPF mailing list [email protected] https://www.ietf.org/mailman/listinfo/ospf
