Re: [Lsr] more feedback on draft-ietf-lsr-isis-srv6-extensions-04

[Chris Bowers <[e-mail]>]

Thanks.  The proposed text below looks good to me.

Chris

On Wed, Feb 5, 2020 at 5:13 AM Peter Psenak <[e-mail]> wrote:

> Hi Chris,
>
> On 05/02/2020 00:27, Chris Bowers wrote:
> > LSR,
> >
> > I have some more feedback on draft-ietf-lsr-isis-srv6-extensions-04 that
> > I am putting in a separate thread so as not to confuse the other thread
> > related to N and A flags.
> >
> > =======
> > The end of Section 5 points out several issues that can result in
> > forwarding not working correctly.  The reader might think that the next
> > section is going to discuss protocol mechanisms to avoid these issues.
> > Since this is not the case, I think it would be helpful to add some text
> > near the end of Section 5 like:
> >
> > "In order to ensure correct forwarding, network operators should take
> > steps to make sure that this requirement is not compromised."
>
> ##PP
> sure.
>
> >
> >
> > =========
> >
> > In section 6, I think it would be useful to explicitly state the
> > following requirement for SRv6 Locator TLVs and their associated SRv6
> SIDs:
> >
> >
> > "When anycast SRv6 Locator TLVs for the same prefix are advertised by
> > different nodes, the SRv6 Locator TLVs MUST all advertise identical sets
> > of SRv6 SIDs."
>
> ##PP
> here's the proposed text:
>
> All the nodes advertising the same anycast locator MUST instantiate the
> exact same set of SIDs under such anycast locator.
>
> >
> >
> > Section 3.3 of RFC 8402 has similar text: "Within an anycast group, all
> > routers in an SR domain MUST advertise the same prefix with the same SID
> > value."  That text only refers to a single SID value, so it seems
> > somewhat open to interpretation text in the context of an SRv6 locator
> > that carries multiple SRv6 SIDs. I think it would be better to avoid any
> > potential ambiguity by using the text proposed above in this document.
> >
> > =========
> >
> > In section 12.1.2. "Revised sub-TLV table" it might avoid an extra
> > interaction with IANA to add a line for the flex-algo prefix metric
> > (currently 6) indicating "n" for TLV#27.
>
> ##PP
> flex-algo prefix metric is not defined in this draft, so I don't believe
> we can mention it here.
>
> thanks,
> Peter
>
> >
> > ==========
> >
> > Thanks,
> >
> > Chris
> >
> >
> >
>
>