Re: [spring] Chair Review of draft-ietf-spring-srv6-srh-compression-11

[Tom Herbert <[e-mail]>]

On Tue, Mar 26, 2024 at 10:14 AM Ron Bonica <[e-mail]> wrote:
>
> Working Group,
>
> Might  SRv6 progress much more quickly if we did the following:
>
> Divorce SRv6 from IPv6
> Give SRv6 its own ethertype
> Let SRv6 progress along its own evolutionary trajectory, unencumbered by IPv6 restrictions
>
> At very least, this divorce would end the long and painful debates regarding IPv6 compliance. And would it give SRv6 more degrees of freedom as it evolves,
>
> As far as I can see, the only benefit of binding SRv6 to IPv6 is in the expectation that IPv6-enabled hardware won't have to change too much to support SRv6. This benefit might still be realized if SRv6 doesn't deviate too much from IPv6.
>
> My question is not rhetorical. Maybe I am missing something, but is there any real benefit in continuing to bind SRRv6 to IPv6?

Ron,

Giving SRV6 its own Ethertype might free it from "restrictions" of
IPv6 (in quotes because some of the restrictions are about eliciting a
robust protocol), but on the other hand a new Ethertype would be a
major undertaking to develop and deploy that might prove to be
infeasible. I believe the best answer is to always require an SRH, and
otherwise maintain compliance with IPv6 standard.

Tom

>
>                                                            Ron
>
> Juniper Business Use Only
>
> ________________________________
> From: Tom Herbert <[e-mail]>
> Sent: Monday, March 25, 2024 3:40 PM
> To: Alvaro Retana <[e-mail]>
> Cc: Robert Raszuk <[e-mail]>; Andrew Alston - IETF <[e-mail]>; Ron Bonica <[e-mail]>; [e-mail] <[e-mail]>; Joel Halpern <[e-mail]>
> Subject: Re: [spring] Chair Review of draft-ietf-spring-srv6-srh-compression-11
>
> [External Email. Be cautious of content]
>
>
> On Mon, Mar 25, 2024 at 12:31 PM Alvaro Retana <[e-mail]> wrote:
> >
> > Tom:
> >
> > Hi!
> >
> > I understand your point.
> >
> > I put the option out there because it came up at last week’s spring meeting and it should be discussed.
>
> Alvaro,
>
> This seems to come back to the fundamental question: is SRv6 still
> IPv6 or is it a new protocol. If it's IPv6 then it should adhere to
> all the requirements and expectations of IPv6, if it's a new protocol
> that is going to diverge from the standard IPv6 then maybe it needs
> its own EtherType and standards development path.
>
> Tom
>
>
> >
> > Thanks!
> >
> > Alvaro.
> >
> >
> > On March 25, 2024 at 2:58:48 PM, Tom Herbert ([e-mail]) wrote:
> >
> > On Mon, Mar 25, 2024 at 11:17 AM Alvaro Retana <[e-mail]> wrote:
> > >
> > > FWIW, I agree with most of what Joel wrote. ;-)
> > >
> > > I see another path forward: Given that the issue is constrained to an SR domain, the draft could also point out the issues as operational/deployment considerations. Operators can then make an informed decision on whether they want to/can use C-SIDs without an SRH in their network. This path forward (or leaving it out of scope, as Joel suggests below) is something the spring WG can reach consensus on by itself (i.e., without needing to consult or agree with other WGs).
> >
> > Alvaro,.
> >
> > This wouldn't be robust and would seem to violate the "be conservative
> > in what you send clause". Punting this to the operators doesn't seem
> > practical either, in an even moderately large network they wouldn't be
> > able to know all the potential problems they might hit in devices.
> > They're about one misconfiguration away from having to debug a rather
> > unpleasant problem. For instance, if operator gets a packet trace from
> > a router they would see a whole bunch of packets with bad checksums,
> > but they would have no way of knowing if these were cases of segment
> > routing or actually corrupted packets.
> >
> > Tom