Re: [bess] Questions to draft-dawra-bess-srv6-services-02

[Robert Raszuk <[e-mail]>]

Hi Linda,

Nope. Nodes except egress have any reason to look at VPN label. That label
has only local significance on egress.

Thx,
R.

On Thu, Oct 3, 2019 at 4:45 PM Linda Dunbar <[e-mail]>
wrote:

> Robert,
>
>
>
> Thank you very much for the explanation.
>
> With the L3VPN case,  there are nodes between Egress and Ingress PEs that
> do look into the VPN label carried by the packets for VRF & IP lookup,
> correct?
>
> I was just confused of the statement about “all nodes between Egress &
> Ingress PE are SR unaware plain IP forwarding nodes”.
>
>
>
> Thanks,
>
>
>
> Linda
>
>
>
> *From:* Robert Raszuk <[e-mail]>
> *Sent:* Thursday, October 03, 2019 3:50 AM
> *To:* Linda Dunbar <[e-mail]>
> *Cc:* [e-mail]; [e-mail]
> *Subject:* Re: [bess] WG adoption and IPR poll for
> draft-dawra-bess-srv6-services-02
>
>
>
> Linda,
>
>
>
> SRv6 services is just a general term used here. Imagine one of such
> service is L3VPN. VPN label (or pointer to it) is needed to be carried
> somewhere in the packet as address space may be overlapping between VPN
> customers and simple IP lookup will not be sufficient to determine VRF or
> exit interface.
>
>
>
> One option which has been done and deployed is to encode it natively in
> the packet and on ingress simply apply prodecures of IPv4 or IPv6
> encapsulation - RFC4797 and RFC7510
>
>
>
> The other new option is to take the VPN label or VPN demux value and
> encode it in SRH or in DO.
>
>
>
> Now which option to choose is left for the operator to decide likely
> depending on a lot of other factors involved.
>
>
>
> Thx,
>
> R.
>
>
>
> On Thu, Oct 3, 2019 at 5:52 AM Linda Dunbar <[e-mail]>
> wrote:
>
> I support WG adoption of the draft, with the following questions. Hope
> authors can help to explain:
>
>
>
> Section 1 Introduction states that the underlay between the Ingress and
> Egress only needs to support plain IPv6
>
> Forwarding. Those plain IPv6 routers don't need to understand the SR
> policies encoded in the payload, correct?
>
> Why need Ingress PE to encapsulate the policy sent by egress PE if all the
> nodes between them are plain IPv6 routers?
>
>
>
> Which PE is to enforce the SR policy?
>
> If the policies are for the egress to enforce, why can't the egress PE
> simply enforce the policy instead of asking ingress node to encapsulate the
> policy in the packet header? Which has the drawback of extra header bits in
> packets.
>
>
>
> Linda Dunbar
>
>
>
>
>
> *From: *"Bocci, Matthew (Nokia - GB)" <[e-mail]>
> *Date: *Friday, September 27, 2019 at 4:00 AM
> *To: *"[e-mail]" <
> [e-mail]>, "[e-mail]" <[e-mail]>
> *Subject: *WG adoption and IPR poll for draft-dawra-bess-srv6-services-02
> *Resent-From: *<[e-mail]>
> *Resent-To: *<[e-mail]>, <[e-mail]>, <
> [e-mail]>, Swadesh Agrawal <[e-mail]>, <
> [e-mail]>, <[e-mail]>, <[e-mail]>, <
> [e-mail]>, <[e-mail]>, <
> [e-mail]>, <[e-mail]>, <
> [e-mail]>
> *Resent-Date: *Friday, September 27, 2019 at 4:00 AM
>
>
>
> Hello,
>
>
>
> This email begins a two-weeks WG adoption poll for
> draft-dawra-bess-srv6-services-02 [1] .
>
>
>
> Please review the draft and post any comments to the BESS working group
> list.
>
>
>
> We are also polling for knowledge of any undisclosed IPR that applies to
> this Document, to ensure that IPR has been disclosed in compliance with
> IETF IPR rules (see RFCs 3979, 4879, 3669 and 5378 for more details).
>
>
>
> If you are listed as an author or a contributor of this document, please
> respond to this email and indicate whether or not you are aware of any
> relevant undisclosed IPR, copying the BESS mailing list. The document won't
> progress without answers from all the authors and contributors.
>
> Currently, there are no IPR disclosures against this document.
>
>
>
> If you are not listed as an author or a contributor, then please
> explicitly respond only if you are aware of any IPR that has not yet been
> disclosed in conformance with IETF rules.
>
>
>
> This poll for adoption closes on Friday 11th October 2019.
>
>
>
> Regards,
>
> Matthew and Stephane
>
>
>
> [1] https://datatracker.ietf.org/doc/draft-dawra-bess-srv6-services/
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