Re: [Isis-wg] [Bier] WGLC: draft-ietf-bier-isis-extensions-04

[Peter Psenak <[e-mail]>]

Hi Tony,

OSPF does not have the original text, so it does not need the new one.

IMHO, the text in section 5 of ISIS BIER draft suits better to the BIER 
architecture draft than to the IGP extension draft.

thanks,
Peter


On 09/02/18 20:17 , Tony Przygienda wrote:
> Sure ;-)  let me ping Peter @ the bottom then ... I don't think any of
> the stuff applies to OSPF (was ISIS nits) except we can consider an
> encaps paragraph. We basically suggest both to replace in ISIS the
> encaps section like this
>
> before:
>
> "
>     All routers in the flooding scope of the BIER TLVs MUST advertise the
>     same encapsulation for a given <MT,SD>.  A router discovering
>     encapsulation advertised that is different from its own MUST report a
>     misconfiguration of a specific <MT,SD>.  All received BIER
>     advertisements associated with the conflicting <MT, SD> pair MUST be
>     ignored.
>
> "
>
> now
>
> "
>
>     Multiple encapsulations MAY be advertised/supported for a given
>     <MT,SD>.  Clearly, however, there MUST be at least one encapsulation
>     type in common in order for a BIER encapsulated packet to be
>     successfully forwarded between two BFRs.
>
> "
>
> I do think that OSPF would benefit from adding this section to clarify
> the issue which is not theoretical now that we have Ethernet.
>
>
> So Peter, any ETA on outstanding OSPF nits now that we're tying up the
> IETF LC?
>
> thanks
>
> --- tony
>
>
> On Fri, Feb 9, 2018 at 11:12 AM, Greg Shepherd <[e-mail]
> <mailto:[e-mail]>> wrote:
>
>     No I didn't. Why would I? These are the changes you and Les worked
>     out. I assumed you'd share them as needed. If for some reason you're
>     uncomfortable engaging with the OSPF draft thread and authors with
>     your proposed changes, let me know and I'll broker the conversation.
>
>     Greg
>
>     On Fri, Feb 9, 2018 at 11:04 AM, Tony Przygienda
>     <[e-mail] <mailto:[e-mail]>> wrote:
>
>         Les has the diff, I'd expect him to publish any minute to the
>         list ... The encaps was a real defect, the rest is just
>         tightening down the language/spec where it was too loose/too
>         strict.
>
>         OSPF still needs update with conversion TLV removed, same
>         paragraph on encaps could be useful. I hope Greg pinged Peter ...
>
>         thanks
>
>         tony
>
>         On Fri, Feb 9, 2018 at 10:58 AM, Alia Atlas <[e-mail]
>         <mailto:[e-mail]>> wrote:
>
>             On Fri, Feb 9, 2018 at 12:46 PM, Tony Przygienda
>             <[e-mail] <mailto:[e-mail]>> wrote:
>
>                 Went last nits with Les, we found one issue (encaps
>                 section was wrong, need to look @ OSPF as well) and
>                 basically tightened language in few places.
>
>
>             K - please get that  out with the details of changes to the
>             list.  I did my AD review back in Oct and looked at the
>             differences before issuing
>             IETF Last Call.
>
>             I look forward to reviewing the minor changes.
>
>             Regards,
>             Alia
>
>                 tony
>
>                 On Tue, Feb 6, 2018 at 3:45 PM, Greg Shepherd
>                 <[e-mail] <mailto:[e-mail]>> wrote:
>
>                     Thanks Les.
>
>                     Any other feedback? Looks like the concerns have
>                     been addressed. Speak now.
>
>                     Cheers,
>                     Greg
>
>                     On Thu, Feb 1, 2018 at 7:26 AM, Les Ginsberg
>                     (ginsberg) <[e-mail]
>                     <mailto:[e-mail]>> wrote:
>
>                         Greg –____
>
>                         __ __
>
>                         This thread is outdated.____
>
>                         In V6 of the draft we removed the restriction to
>                         limit IS-IS BIER support to area boundaries – so
>                         Toerless’s comment (and my proposed text) are no
>                         longer relevant.____
>
>                         __ __
>
>                         Specifically:____
>
>                         __ __
>
>                         Section 4.1:____
>
>                         __ __
>
>                         “At present, IS-IS support for a given BIER
>                         domain/sub-domain is ____
>
>                                             limited to a single area -
>                         or to the IS-IS L2 sub-domain.”____
>
>                         __ __
>
>                         The above text was removed.____
>
>                         __ __
>
>                         Section 4.2____
>
>                         __ __
>
>                         o  BIER sub-TLVs MUST NOT be included when a
>                         prefix reachability____
>
>                                advertisement is leaked between levels.____
>
>                         __ __
>
>                         Was changed to____
>
>                         __ __
>
>                         o  BIER sub-TLVs MUST be included when a prefix
>                         reachability____
>
>                                advertisement is leaked between levels.____
>
>                         __ __
>
>                         This aligns IS-IS and OSPF drafts in this
>                         regard.____
>
>                         __ __
>
>                              Les____
>
>                         __ __
>
>                         *From:*Greg Shepherd [mailto:[e-mail]
>                         <mailto:[e-mail]>]
>                         *Sent:* Thursday, February 01, 2018 2:23 AM
>                         *To:* Toerless Eckert <[e-mail]
>                         <mailto:[e-mail]>>
>                         *Cc:* Les Ginsberg (ginsberg)
>                         <[e-mail]
>                         <mailto:[e-mail]>>; Tony Przygienda
>                         <[e-mail]
>                         <mailto:[e-mail]>>; Hannes Gredler
>                         ([e-mail] <mailto:[e-mail]>)
>                         <[e-mail] <mailto:[e-mail]>>;
>                         [e-mail] <mailto:[e-mail]>;
>                         [e-mail] <mailto:[e-mail]> list
>                         <[e-mail] <mailto:[e-mail]>>;
>                         Christian Hopps <[e-mail]
>                         <mailto:[e-mail]>>
>
>
>                         *Subject:* Re: [Bier] WGLC:
>                         draft-ietf-bier-isis-extensions-04____
>
>                         __ __
>
>                         Have these changes been reflected in the draft?
>                         We're in WGLC but this discussion needs to come
>                         to a conclusion so we can progress. ____
>
>                         __ __
>
>                         Greg____
>
>                         __ __
>
>                         On Tue, Jul 25, 2017 at 12:52 PM, Toerless
>                         Eckert <[e-mail] <mailto:[e-mail]>>
>                         wrote:____
>
>                             Thanks, Less, that would be lovely!
>
>                             I didn't check the OSPF draft, if its
>                             similar state, explanatory text wold equally
>                             be appreciated.____
>
>
>                             On Sun, Jul 23, 2017 at 11:28:08PM +0000,
>                             Les Ginsberg (ginsberg) wrote:
>                              > Toerless -
>                              >
>                              > I am thinking to add a statement in
>                             Section 4.1 - something like:
>                              >
>                              > "At present, IS-IS support for a given
>                             BIER domain/sub-domain is limited to a
>                             single area - or to the IS-IS L2 sub-domain."
>                              >
>                              > If you believe this would be helpful I
>                             will spin a new version (subject to
>                             review/agreement from my co-authors).
>                              >
>                              >    Les
>                              >
>                              >
>                              > > -----Original Message-----
>                              > > From: Toerless Eckert
>                             [mailto:[e-mail] <mailto:[e-mail]>]
>                              > > Sent: Saturday, July 22, 2017 6:34 AM
>                              > > To: Les Ginsberg (ginsberg)
>                              > > Cc: Tony Przygienda; Hannes Gredler
>                             ([e-mail]
>                             <mailto:[e-mail]>); Greg Shepherd;
>                              > > [e-mail] <mailto:[e-mail]>;
>                             [e-mail] <mailto:[e-mail]>
>                             list; Christian Hopps
>                              > > Subject: Re: [Bier] WGLC:
>                             draft-ietf-bier-isis-extensions-04
>                              > >
>                              > > Thanks Les
>                              > >
>                              > > When searching various terms in the doc
>                             to figure out what happens i am not
>                              > > sure why i missed this one.
>                              > >
>                              > > But: IMHO, RFCs can not only be the
>                             minimum number of words to get a
>                              > > running implementation. It also needs
>                             to specify what this implementation
>                              > > intends to achieve. Otherwise its not
>                             possible to do a useful review:
>                              > > The reviewer can to verify whether the
>                             spec will achieve what it claims to
>                              > > achieve is there no definitionn of what
>                             it claims to achieve.
>                              > >
>                              > > If i understand ISIS correctly, my
>                             reverse engineering of the intent is:
>                              > >
>                              > > - BIER TLVs stay within single ISIS
>                             areas. BFIR and BFER must therefore be
>                              > >   in the same ISIS area: There is no
>                             inter-area BIER traffic possible
>                              > >   with this specification. This is also
>                             true for ISIS area 0.
>                              > >
>                              > > - The same BIER sub-domain identifiers
>                             can be re-used
>                              > >   across different ISIS areas without
>                             any current impact. If these BFR-IDs
>                              > >   are non-overlapping, then this would
>                             allow in the future to create a single
>                              > >   cross ISIS area BIER sub-domain by
>                             leaking TLVs for such a BIER sub-domain
>                              > >   across ISIS levels. Leakage is
>                             outside the scope of this specificication.
>                              > >
>                              > > I actually even would like to do the
>                             following:
>                              > >
>                              > > - If BIER sub-domains are made to span
>                             multiple ISIS areas and BFR-ids
>                              > > assignemtns
>                              > >   are made such that all BFR-ids with
>                             the same SI are in the same ISIS ara,
>                              > >   then it should be in the future
>                             reasonably easy to create inter-area BIER
>                              > >   not by leaking of the BIER TLV but by
>                             having BFIR MPLS unicastBIER packets
>                              > >   for different SIs to an appropriate
>                             L2L1 BFIR that is part of the destination
>                              > > area/SI.
>                              > >   (if you would use SI number that are
>                             the same as ISIS area numbers then
>                              > >    you could probably do this without
>                             any new signaling. Not quite sure if
>                              > >    you can today easily find L1L2
>                             border router for another area via existing
>                              > >    TLVs).
>                              > >
>                              > >   Alas, this idea will probably be
>                             killed because of the BIER architecture
>                              > >   intent not to engineer SI assignments
>                             in geographical fashions to
>                              > >   minimize traffic duplication in the
>                             presence of multiple SIs.
>                              > >
>                              > > Cheers
>                              > >     Toerless
>                              > >
>                              > > On Sat, Jul 22, 2017 at 06:03:53AM
>                             +0000, Les Ginsberg (ginsberg) wrote:
>                              > > > Tony/Toerless ???
>                              > > >
>                              > > > There is an explicit statement as to
>                             scope:
>                              > > >
>                              > > > <snip>
>                              > > > Section 4.2
>                              > > > ???
>                              > > >    o  BIER sub-TLVs MUST NOT be
>                             included when a prefix reachability
>                              > > >       advertisement is leaked between
>                             levels.
>                              > > > <end snip>
>                              > > >
>                              > > > Tony seems to have forgotten that we
>                             had a discussion about how BIER
>                              > > might be supported across areas and the
>                             conclusion was we did not know
>                              > > how to do that yet.
>                              > > > (Sorry Tony)
>                              > > >
>                              > > > Note this is ???consistent??? with
>                             https://www.ietf.org/id/draft-ietf-bier-
>                             <https://www.ietf.org/id/draft-ietf-bier->
>                              > > ospf-bier-extensions-07.txt Section
>                             2.5<https://www.ietf.org/id/draft-ietf-
>                             <https://www.ietf.org/id/draft-ietf->
>                              > >
>                             bier-ospf-bier-extensions-07.txt%20Section%202.5>
>                             - which limits the
>                              > > flooding scope of BIER information to a
>                             single area unless it can be validated
>                              > > that the best path to the prefix with
>                             BIER info can be validated to be to a
>                              > > router which itself advertised the BIER
>                             info. This is not something IS-IS can do
>                              > > since a single IS-IS instance only
>                             supports one area and therefore does not
>                              > > have the Level-1 advertisements of the
>                             originating router when that router is
>                              > > in another area.
>                              > > >
>                              > > > A few more responses inline.
>                              > > >
>                              > > > From: BIER
>                             [mailto:[e-mail]
>                             <mailto:[e-mail]>] On Behalf Of
>                             Tony Przygienda
>                              > > > Sent: Friday, July 21, 2017 5:17 AM
>                              > > > To: Toerless Eckert
>                              > > > Cc: Hannes Gredler ([e-mail]
>                             <mailto:[e-mail]>); Greg Shepherd;
>                             [e-mail] <mailto:[e-mail]>;
>                              > > > [e-mail]
>                             <mailto:[e-mail]> list; Christian Hopps
>                              > > > Subject: Re: [Bier] WGLC:
>                             draft-ietf-bier-isis-extensions-04
>                              > > >
>                              > > > Terminology is a bit nits  IMO since
>                             the doc is reading clear enough for
>                              > > someone who read BIER & ISIS. I can
>                             reread it or Les can comment whether
>                              > > we should tighten glossary ...
>                              > > >
>                              > > > With the scope I agree, that got lost
>                             and the doc should be possibly rev'ed
>                              > > before closing LC. Yes, we flood AD
>                             wide was the agreement but something
>                              > > mentioning that this could change in
>                             the future is good so we are forced to
>                              > > give it some thought how that would
>                             transition ...
>                              > > >
>                              > > > Thinking further though, in ISIS we
>                             have a clean document really. The  BIER
>                              > > sub-TLVs go into well defined TLVs in
>                             terms of flooding scope. Normal L1-L2
>                              > > redistribution can be used to get the
>                             info to all needed places AFAIS. So
>                              > > maybe nothing needs to be written. I
>                             wait for Les to chime in.
>                              > > >
>                              > > > OSPF I would have to look @ scopes
>                             again & think whether we need to
>                              > > write something or maybe Peter can
>                             comment ...
>                              > > >
>                              > > > --- tony
>                              > > >
>                              > > >
>                              > > >
>                              > > > On Fri, Jul 21, 2017 at 8:27 AM,
>                             Toerless Eckert
>                              > > <[e-mail]
>                             <mailto:[e-mail]><mailto:[e-mail]
>                             <mailto:[e-mail]>>> wrote:
>                              > > > Sorry, past the two weeks, but
>                             hopefully  benign textual comments:
>                              > > >
>                              > > > We tried to find an explicit
>                             statement about the scope of BIER TLVs - eg:
>                              > > > are they meant to stay within an
>                             area, have some redistribution across
>                              > > > areas/levels or not.
>                              > > >
>                              > > > Tony said WG agreement was to have
>                             these TLV be flooded across the
>                              > > > whole ISIS domain for now (this
>                             draft). So an explicit statement to that
>                              > > effect would
>                              > > > be great (All BIER sub-domains TLVs
>                             are flooded across all ISIS areas/levels,
>                              > > so they span the whole ISIS domain).
>                              > > >
>                              > > > Also, if future work may/should could
>                             improve on that maybe some
>                              > > > sentence about that (i guess one
>                             could just have ISIS intra-area BIER sub-
>                              > > domains ?).
>                              > > >
>                              > > > Also: Do a check about possible
>                             ambiguity of any generic terms like
>                              > > sub-domain, level, area, topology so
>                             that reader that don't know the
>                              > > terminology ofall protocols (ISIS,
>                             BIER) by heart can easily know which
>                              > > protocol is referred to.
>                              > > >
>                              > > > [Les:] There is no mention of
>                             ???level??? in the document.
>                              > > > The use of ???sub-domain??? is
>                             clearly always associated with ???BIER???.
>                              > > > ???topology??? is always used as an
>                             RFC 5120 topology ??? therefore
>                              > > clearly an IS-IS topology.
>                              > > > There is only one use of the term
>                             ???area??? (in Section 5.1). That text
>                              > > might deserve a bit of clarification
>                             given this might be either a Level 1 area or
>                              > > the Level2 sub-domain. I???ll take a
>                             pass at it.
>                              > > > (BTW ??? I am talking about IS-IS
>                             area/L2sub-domain Toerless. ???)
>                              > > >
>                              > > > I don???t see that any other
>                             clarification is needed ??? but Toerless ??? if
>                              > > you can point to any specific
>                             sentences/paragraphs which you find confusing
>                              > > - I???ll take a second look.
>                              > > >
>                              > > >    Les
>                              > > >
>                              > > >
>                              > > > I guess there are no BIER level, area
>                             or topologies, but still makes
>                              > > > reading easier if the doc would say
>                             "ISIS level", "ISIS area", or at
>                              > > > least have them in the Terminology
>                             section. And probably in
>                              > > > terminology say "domain -> in the
>                             context of this document the BIER
>                              > > domain which is also the same as the
>                             ISIS domain"
>                              > > > (which i hope is the correct
>                             statement, see above).
>                              > > >
>                              > > > Cheers
>                              > > >     Toerless
>                              > > >
>                              > > >
>                             _______________________________________________
>                              > > > BIER mailing list
>                              > > > [e-mail]
>                             <mailto:[e-mail]><mailto:[e-mail]
>                             <mailto:[e-mail]>>
>                              > > >
>                             https://www.ietf.org/mailman/listinfo/bier
>                             <https://www.ietf.org/mailman/listinfo/bier>
>                              > > >
>                              > > >
>                              > > >
>                              > > > --
>                              > > > We???ve heard that a million monkeys
>                             at a million keyboards could
>                              > > produce the complete works of
>                             Shakespeare; now, thanks to the Internet,
>                              > > we know that is not true.
>                              > > > ???Robert Wilensky
>                              > >
>                              > > --
>                              > > ---
>                              > > [e-mail] <mailto:[e-mail]>____
>
>                         __ __
>
>
>
>
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