Gyan - The paragraph you cut and pasted is providing a short overview of Segment Routing, which can be used on two different data planes - IPv6 and MPLS.
The introduction goes on to say: "This draft describes the necessary IS-IS extensions that need to be introduced for Segment Routing operating on an MPLS data-plane." An MPLS dataplane supports forwarding of both IPv4 and IPv6 packets - and the document makes that clear throughout. Extensions for IS-IS to support Segment Routing over an IPv6 dataplane are described in https://datatracker.ietf.org/doc/draft-bashandy-isis-srv6-extensions/ . Les > -----Original Message----- > From: Lsr <[email protected]> On Behalf Of Gyan Mishra > Sent: Tuesday, May 14, 2019 7:09 PM > To: Mirja Kühlewind <[email protected]> > Cc: [email protected]; Christian Hopps > <[email protected]>; [email protected]; > [email protected]; [email protected]; The IESG <[email protected]>; > [email protected] > Subject: Re: [Lsr] Mirja Kühlewind's No Objection on draft-ietf-isis-segment- > routing-extensions-24: (with COMMENT) > > > I noticed in the intro that IPv4 is not mentioned just IPv6 and mpls. Was > that > on purpose. > > Segment Routing (SR) allows for a flexible definition of end-to-end > paths within IGP topologies by encoding paths as sequences of > topological sub-paths, called "segments". These segments are > advertised by the link-state routing protocols (IS-IS and OSPF). > Prefix segments represent an ECMP-aware shortest-path to a prefix (or > a node), as per the state of the IGP topology. Adjacency segments > represent a hop over a specific adjacency between two nodes in the > IGP. A prefix segment is typically a multi-hop path while an > adjacency segment, in most of the cases, is a one-hop path. SR’s > control-plane can be applied to both IPv6 and MPLS data-planes, and > does not require any additional signaling (other than the regular > IGP). For example, when used in MPLS networks, SR paths do not > require any LDP or RSVP-TE signaling. Still, SR can interoperate in > the presence of LSPs established with RSVP or LDP. > > Gyan Mishra > Verizon Communications > Phone: 301 502-1347 > > Sent from my iPhone > > > On May 14, 2019, at 7:58 AM, Mirja Kühlewind via Datatracker > <[email protected]> wrote: > > > > Mirja Kühlewind has entered the following ballot position for > > draft-ietf-isis-segment-routing-extensions-24: No Objection > > > > 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 > > 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-isis-segment-routing- > extensions/ > > > > > > > > ---------------------------------------------------------------------- > > COMMENT: > > ---------------------------------------------------------------------- > > > > A few comments/questions: > > > > 1) For both the Prefix Segment Identifier and the Adjacency Segment > Identifier > > sub-TLV it is not fully clear to me what the value field is used for when > > the > > V-Flag is set. Can you further elaborate this in the draft or provide a > > respective pointer? > > > > 2) The F-Flag in Adjacency Segment Identifier sub-TLV and SID/Label > Binding TLV > > is only one bit. I'm not expecting a new version of IP any time soon, > however, > > maybe completely different address families could be useful as well. Not > sure > > if only 1 bit is future-proof...? > > > > 3) Would it make sense to also discuss any risk of leaking information (e.g. > > about the network topology) in the security consideration section? > > > > > > _______________________________________________ > > Lsr mailing list > > [email protected] > > https://www.ietf.org/mailman/listinfo/lsr > > _______________________________________________ > Lsr mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/lsr _______________________________________________ Lsr mailing list [email protected] https://www.ietf.org/mailman/listinfo/lsr
