Re: [Lsr] Mirja Kühlewind's No Objection on draft-ietf-isis-segment-routing-extensions-24: (with COMMENT)

Les

I agree the document makes it clear throughout that then mpls dataplane
supports ipv4 and ipv6  however in the short Overview at the top I think it
should say the following:

SR’s control-plane can be applied to both IPv4 and IPv6 MPLS data-planes,
and
does not require any additional signaling (other than the regular IGP)

Wording seems misleading leaving out IPv4.

Gyan Mishra
Verizon Communications
Phone: 301 502-1347

On Wed, May 15, 2019 at 1:02 AM Les Ginsberg (ginsberg) <ginsberg@cisco.com>
wrote:

> 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 <lsr-bounces@ietf.org> On Behalf Of Gyan Mishra
> > Sent: Tuesday, May 14, 2019 7:09 PM
> > To: Mirja Kühlewind <ietf@kuehlewind.net>
> > Cc: draft-ietf-isis-segment-routing-extensions@ietf.org; Christian Hopps
> > <chopps@chopps.org>; uma.chunduri@huawei.com;
> > aretana.ietf@gmail.com; lsr-chairs@ietf.org; The IESG <iesg@ietf.org>;
> > lsr@ietf.org
> > 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
> > <noreply@ietf.org> 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
> > > Lsr@ietf.org
> > > https://www.ietf.org/mailman/listinfo/lsr
> >
> > _______________________________________________
> > Lsr mailing list
> > Lsr@ietf.org
> > https://www.ietf.org/mailman/listinfo/lsr
>
-- 
Gyan S. Mishra
IT Network Engineering & Technology Consultant
Routing & Switching / Service Provider MPLS & IPv6 Expert
www.linkedin.com/in/GYAN-MISHRA-RS-SP-MPLS-IPV6-EXPERT
Mobile – 202-734-1000