Re: [Lsr] John Scudder's No Objection on draft-ietf-lsr-isis-srv6-extensions-14: (with COMMENT)

["Les Ginsberg (ginsberg)" <[e-mail]>]

Sorry folks - one more attempt to correct what I see as inappropriate dependencies.

Codepoint registries are created in part precisely to avoid having to update pre-existing documents when we need to add additional codepoints to the registry. The registry is the living entity and when additions are required we update the registry - not older documents which have contributed to the existing contents of the registry. Nor do we have to generate a new document to present the updated contents of the registry. All of that is handled simply by updating the registry.

The only legitimate reason to update an older document would be if we are actually changing in some way one or more of the existing codepoints already defined in the registry. That is not happening here.

The suggestion that RFC 7370 needs to be "updated" because draft-ietf-lsr-isis-srv6-extensions requires additions to an existing registry first created by RFC 7370 stands the dependency relationship between a registry and the document(s) which specify entries in the registry on its head.

The argument here seems to be that we are "changing the name of the registry" - hence the document that first created the registry with the existing name has to be considered as updated. This is illogical. The renaming of the registry in no way alters any of the existing codepoints.
This is certainly not what was done when RFC 8668 modified https://www.iana.org/assignments/isis-tlv-codepoints/isis-tlv-codepoints.xhtml#isis-tlv-codepoints-22-23-25-141-222-223  - another registry created by RFC 7370.

Perhaps the somewhat unfortunate choice of the name of the registry - which inserts the codepoint for all the TLVs supported by the registry into the registry name - feeds into this confusion.
If so, I would suggest renaming the registry to:  "Sub-TLVs for TLVs advertising NLRI".
The registry name would then never have to be changed and we could more easily avoid being drawn into an inappropriate use of "update".

   Les



> -----Original Message-----
> From: Acee Lindem (acee) <[e-mail]>
> Sent: Monday, May 17, 2021 7:03 AM
> To: Peter Psenak (ppsenak) <[e-mail]>; John Scudder
> <jgs=[e-mail]>
> Cc: Alvaro Retana <[e-mail]>; Les Ginsberg (ginsberg)
> <[e-mail]>; John Scudder via Datatracker <[e-mail]>;
> [e-mail]; [e-mail]; [e-mail];
> The IESG <[e-mail]>; Christian Hopps <[e-mail]>
> Subject: Re: John Scudder's No Objection on draft-ietf-lsr-isis-srv6-
> extensions-14: (with COMMENT)
> 
> Hi Peter,
> 
> On 5/17/21, 9:07 AM, "Peter Psenak" <[e-mail]> wrote:
> 
>     Hi Acee,
> 
>     On 17/05/2021 14:56, Acee Lindem (acee) wrote:
>     > Hi John,
>     >
>     > Yes – I think “updates” should be removed. Registries are created
>     > explicitly for the purpose of tracking extensions and every document
>     > that adds to a registry should not update the document creating that
>     > registry. Now if the definition or application of the registry were
>     > changed, which I don’t believe is the case here, then we could consider
>     > “updates”.
> 
>     RFC 7370 created the registry by merging multiple existing registries.
>     It did not really defined any new functionality.
> 
>     We are changing the name of that merged registry. Given that RFC 7370
>     did not define anything new, just defined the merged registry, one can
>     consider the name change as an update to RFC 7370.
> 
> Ok - I missed that. I agree with that it updates RFC 7370 since the registry
> name changed as opposed to simply adding code points.
> 
> Thanks,
> Acee
> 
>     thanks,
>     Peter
>     >
>     > Thanks,
>     >
>     > Acee
>     >
>     > *From: *John Scudder <jgs=[e-mail]>
>     > *Date: *Monday, May 17, 2021 at 8:48 AM
>     > *To: *Acee Lindem <[e-mail]>
>     > *Cc: *Alvaro Retana <[e-mail]>, "Les Ginsberg
> (ginsberg)"
>     > <[e-mail]>, "Peter Psenak (ppsenak)"
> <[e-mail]>, John
>     > Scudder via Datatracker <[e-mail]>,
>     > "[e-mail]"
>     > <[e-mail]>, "[e-mail]"
>     > <[e-mail]>, "[e-mail]" <[e-mail]>, The IESG
>     > <[e-mail]>, Christian Hopps <[e-mail]>
>     > *Subject: *Re: John Scudder's No Objection on
>     > draft-ietf-lsr-isis-srv6-extensions-14: (with COMMENT)
>     >
>     > Acee,
>     >
>     > I think you are saying you prefer to remove the “updates”. Is that
>     > right? It was a little confusing given the reply chain.
>     >
>     > (I’ve already given my opinion but said I’m not going to go to the mat
>     > over it.)
>     >
>     > —John
>     >
>     >
>     >
>     >     On May 17, 2021, at 8:21 AM, Acee Lindem (acee)
>     >     <acee=[e-mail]> wrote:
>     >
>     >     That we be my preference as well. We’ve had several discussions on
>     >     what constitutes “update” and I believe that the consensus was that
>     >     a document isn’t “updated” unless the current behavior is changed.
>     >     If we’ve done our jobs, protocols are designed to be extended and
>     >     these extensions shouldn’t constitute updates.
>     >
>     >     Thanks,
>     >
>     >     Acee
>     >
>     >     *From: *Alvaro Retana <[e-mail]>
>     >     *Date: *Monday, May 17, 2021 at 6:55 AM
>     >     *To: *"Les Ginsberg (ginsberg)" <[e-mail]>, "Peter Psenak
>     >     (ppsenak)" <[e-mail]>, John Scudder
>     >     <jgs=[e-mail]>
>     >     *Cc: *John Scudder via Datatracker <[e-mail]>,
>     >     "[e-mail]"
>     >     <[e-mail]>, "[e-mail]"
>     >     <[e-mail]>, "[e-mail]" <[e-mail]>, The
>     >     IESG <[e-mail]>, Christian Hopps <[e-mail]>
>     >     *Subject: *Re: John Scudder's No Objection on
>     >     draft-ietf-lsr-isis-srv6-extensions-14: (with COMMENT)
>     >     *Resent-From: *<[e-mail]>
>     >     *Resent-To: *Yingzhen Qu <[e-mail]>, Christian
> Hopps
>     >     <[e-mail]>, Acee Lindem <[e-mail]>
>     >     *Resent-Date: *Monday, May 17, 2021 at 6:54 AM
>     >
>     >     Peter:
>     >
>     >     Hi!
>     >
>     >     As John mentioned, "Since for better or worse we don’t have a firm
>     >     definition of when we do, and don’t, use “updates”, it comes down to
>     >     a matter of personal taste in the end.”
>     >
>     >     I rather you leave it in.
>     >
>     >     Thanks!
>     >
>     >     Alvaro.
>     >
>     >     On May 17, 2021 at 6:42:48 AM, Peter Psenak ([e-mail]
>     >     <mailto:[e-mail]>) wrote:
>     >
>     >         John, Alvaro,
>     >
>     >         do we have a consensus whether we need the update to RFC 7370 or
>     >         not?
>     >
>     >
>     >         thanks,
>     >         Peter
>     >
>     >
>     >
>     >         On 13/05/2021 21:12, Les Ginsberg (ginsberg) wrote:
>     >          > Alvaro –
>     >          >
>     >          > FWIW, I agree w John here.
>     >          >
>     >          > There are many examples – to cite a few:
>     >          >
>     >          > Sub-TLVs for TLVs 22, 23, 25, 141, 222, and 223 (Extended IS
>     >          > reachability, IS Neighbor Attribute, L2 Bundle Member
>     >         Attributes,
>     >          > inter-AS reachability information, MT-ISN, and MT IS Neighbor
>     >         Attribute
>     >          > TLVs)
>     >          >
>     >          > …
>     >          >
>     >          > Reference
>     >          >
>     >          >     [RFC5305][RFC5316][RFC7370][RFC8668]
>     >          >
>     >          > RFC 8868 is not marked as updating RFC 7370.
>     >          >
>     >          > RFC 7370 is not marked as updating RFC 5316/RFC 5305.
>     >          >
>     >          > Sub-TLVs for TLVs 135, 235, 236, and 237 (Extended IP
>     >         reachability, MT
>     >          > IP. Reach, IPv6 IP. Reach, and MT IPv6 IP. Reach TLVs)
>     >          >
>     >          > …
>     >          >
>     >          > Reference
>     >          >
>     >          >     [RFC5305][RFC7370]
>     >          >
>     >          > Again, RFC7370 is not marked as updating RFC 5305.
>     >          >
>     >          > I think it is sufficient to request that IANA add the new RFC
>     >         to the
>     >          > list of References for the modified registry.
>     >          >
>     >          >    Les
>     >          >
>     >          > *From:* Lsr <[e-mail]
>     >         <mailto:[e-mail]>> *On Behalf Of *John Scudder
>     >          > *Sent:* Thursday, May 13, 2021 11:00 AM
>     >          > *To:* Alvaro Retana <[e-mail]
>     >         <mailto:[e-mail]>>
>     >          > *Cc:* John Scudder via Datatracker <[e-mail]
>     >         <mailto:[e-mail]>>; Christian Hopps
>     >          > <[e-mail] <mailto:[e-mail]>>;
>     >         [e-mail] <mailto:[e-mail]>; The IESG
>     >         <[e-mail] <mailto:[e-mail]>>;
>     >          > [e-mail]
>     >         <mailto:[e-mail]>;
>     >         [e-mail] <mailto:[e-mail]>
>     >          > *Subject:* Re: [Lsr] John Scudder's No Objection on
>     >          > draft-ietf-lsr-isis-srv6-extensions-14: (with COMMENT)
>     >          >
>     >          > On May 13, 2021, at 1:20 PM, Alvaro Retana
>     >         <[e-mail] <mailto:[e-mail]>
>     >          > <mailto:[e-mail]
>     >         <mailto:[e-mail]>>> wrote:
>     >          >
>     >          >   This documents updates RFC 7370 by modifying an existing
>     >          > registry.
>     >          >
>     >          > Also, this doesn’t seem to me like an update to RFC 7370. It’s
>     >          > normal for an
>     >          > RFC to update an IANA registry, without saying it updates a
>     >          > previous RFC that
>     >          > established that registry. I think the “updates” just confuses
>     >          > matters and
>     >          > clutters things up, and should be removed.
>     >          >
>     >          >
>     >          > In this case the document is not only registering a value.
>     >         It is
>     >          > changing the name of the registry, adding an extra column, and
>     >          > updating all the other entries (§11.1.*).  The Updates tag is
>     >         used
>     >          > because it significantly changes the registry.
>     >          >
>     >          > Still seems unnecessary to me, registries are moving targets,
>     >         citation
>     >          > of all the relevant RFCs in their references should be
>     >         sufficient. So,
>     >          > the registry would be updated so that it cited both this spec
>     >         and 7370,
>     >          > and someone wanting to know “how did the registry get this
>     >         way?” would
>     >          > be able to work it out.
>     >          >
>     >          > I’m not going to fight about it; the “updates” is not very
>     >         harmful. I
>     >          > say “not very” because the diligent reader might be led to
>     >         think they
>     >          > need to go read RFC 7370 in order to properly understand this
>     >         spec, and
>     >          > waste some time realizing that isn’t true. Since for better
>     >         or worse we
>     >          > don’t have a firm definition of when we do, and don’t, use
>     >         “updates”, it
>     >          > comes down to a matter of personal taste in the end.
>     >          >
>     >          > $0.02,
>     >          >
>     >          > —John
>     >          >
>     >
>