BGP Link-State Shortest Path First (SPF) Routing
draft-ietf-lsvr-bgp-spf-51

[Ballot comment]
Section 5.1.2, paragraph 3
>    The BGP-LS attribute may potentially be quite large depending on the
>    amount of link-state information associated with a single Link-State
>    NLRI.  The BGP specification [RFC4271] mandates a maximum BGP message
>    size of 4096 octets.  It is RECOMMENDED that an implementation
>    support [RFC8654] in order to accommodate a greater amount of
>    information within the BGP-LS Attribute.  BGP SPF speakers MUST
>    ensure that they limit the TLVs included in the BGP-LS Attribute to
>    ensure that a BGP update message for a single Link-State NLRI does
>    not cross the maximum limit for a BGP message.  The determination of
>    the types of TLVs to be included by the BGP SPF speaker originating
>    the attribute is outside the scope of this document.  When a BGP SPF
>    speaker finds that it is exceeding the maximum BGP message size due
>    to addition or update of some other BGP Attribute (e.g., AS_PATH), it
>    MUST consider the BGP-LS Attribute to be malformed and the attribute
>    discard handling of [RFC7606] applies.

I support John and his DISCUSS here. It is clear that what RFC 7606 describes as handling of malformed attributes applies to the reception of a BGP UPDATE message, not to the construction of one. Therefore, using "attribute discard" as described in RFC 7606 doesn't directly translate to the transmission process.

One way to handle this would be to say:

"When a BGP SPF speaker determines that adding the BGP-LS Attribute would cause the BGP message to exceed the maximum permissible size, it MUST omit the BGP-LS Attribute from the message."

The IANA review of this document seems to not have concluded yet.

-------------------------------------------------------------------------------
NIT
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All comments below are about very minor potential issues that you may choose to
address in some way - or ignore - as you see fit. Some were flagged by
automated tools (via https://github.com/larseggert/ietf-reviewtool), so there
will likely be some false positives. There is no need to let me know what you
did with these suggestions.

Document references draft-ietf-lsvr-applicability-17, but -20 is the latest
available revision.

Section 5.2, paragraph 2
> ker receiving a BGP Update containing a SPF Status TLV in the BGP-LS attribut
>                                      ^
Use "an" instead of "a" if the following word starts with a vowel sound, e.g.
"an article", "an hour".

Section 5.2.2.1, paragraph 2
> ker receiving a BGP Update containing a SPF Status TLV in the BGP-LS attribut
>                                      ^
Use "an" instead of "a" if the following word starts with a vowel sound, e.g.
"an article", "an hour".

Section 5.2.2.2, paragraph 5
> ker receiving a BGP Update containing a SPF Status TLV in the BGP-LS attribut
>                                      ^
Use "an" instead of "a" if the following word starts with a vowel sound, e.g.
"an article", "an hour".

Section 6, paragraph 1
> t recent Sequence Number TLV, i.e., highest sequence number is selected. 3. T
>                                    ^^^^^^^
A determiner may be missing.

Section 6.1.1, paragraph 3
>  have been used. The algorithm is comprised of the steps below: 1. The curre
>                                ^^^^^^^^^^^^^^^
Did you mean "comprises" or "consists of" or "is composed of"?

Section 6.3, paragraph 15
> ised so that an unnumbered link can used in the SPF computation for multiple
>                                    ^^^^
Did you mean "be used"?

Section 6.3, paragraph 25
> 6.5.2. Node Failure Convergence By default [RFC4271], all the NLRI advertised
>                                ^^^^^^^^^^
Did you mean: "By default,"?

Section 9, paragraph 1
> cting the BGP-LS-SPF AFI/SAFI or vice-versa, isolation mechanisms such as se
>                                  ^^^^^^^^^^
The expression "vice versa" is spelled without hyphens.

[Ballot comment]
Thank you to Joel Halpern for the GENART review.

** Section 8.2
  Deprecated TLV types include the SPF
  Capability TLV type, IPv4 Prefix Length TLV type, and IPv6 Prefix
  Length TLV type.
...
  The early allocation assignments for the TLV types SPF Capability
  (1180), IPv4 Prefix Length (1182), and IPv6 Prefix Length (1183) are
  no longer required and are to be deprecated.

The names “IPv4 Prefix Length” and “IPv6 Prefix Length” noted twice are inconsistent with the names in the IANA registry:

1182 IPv4 Link Prefix Length [draft-ietf-lsvr-bgp-spf-20]

1183 IPv6 Link Prefix Length [draft-ietf-lsvr-bgp-spf-20]

It appears that “Link” is missing in both names.

[Ballot discuss]
My well-known personal opinions about the advisability of this technology notwithstanding, I was pleasantly surprised by how well-baked this document is. Nonetheless, I have thoughts. You're not surprised, right?

## DISCUSS

### Section 5.1.2

                                                        When a BGP SPF
  speaker finds that it is exceeding the maximum BGP message size due
  to addition or update of some other BGP Attribute (e.g., AS_PATH), it
  MUST consider the BGP-LS Attribute to be malformed and the attribute
  discard handling of [RFC7606] applies.
 
I don't get this. RFC 7606 is all about what to do at receive time, when a BGP speaker is receiving and processing an update. Here, you are talking about what to do when you're constructing an update you want to send. What does it mean to apply attribute discard in that context? As a reminder, here is how RFC 7606 describes attribute discard:

  o  Attribute discard: In this approach, the malformed attribute MUST
      be discarded and the UPDATE message continues to be processed.
      This approach MUST NOT be used except in the case of an attribute
      that has no effect on route selection or installation.

It's hard for me to see how the BGP-LS Attribute "has no effect on route selection or installation", but that's secondary to the concern that RFC 7606 attribute discard has no meaning on the transmit side.

Maybe you mean something like this:

                                                        When a BGP SPF
  speaker finds that it is exceeding the maximum BGP message size due
  to addition or update of some other BGP Attribute (e.g., AS_PATH), it
  MUST NOT send the BGP-LS Attribute.

By the way, I see this text was essentially pasted from RFC 9552 Section 5.3. I regret not catching the error when balloting on that document, but I'll also point out that 9552 is considerably more detailed in instructing the implementor what to do (Section 8.2.2) so the defect isn't as serious there.

### Section 5.2.1.1

  The BGP-LS-SPF Node NLRI Attribute SPF Status TLV, Link NLRI
  Attribute SPF Status TLV, and Prefix NLRI Attribute SPF Status TLV
  use the same TLV Type (1184).  This implies that a BGP Update will
  include a single NLRI.

I found it very hard to understand what you were getting at with "This implies that a BGP Update will include a single NLRI." My guess is you mean, since you busy out a node/link/prefix using this TLV, and since the TLV is packed into a path attribute and not into the NLRI itself, then it would almost never make sense to pack together (say) a Node NLRI and a Link NLRI in the same Update.

I'm guessing it almost never makes sense to pack together different BGP-LS NLRI in the same Update anyway (as an aside, this is one way in which BGP-LS is on-paper less scalable than normal BGP). I wonder if it's worth having a different subsection on expectations and requirements on update packing. If you don't do that, I think this sentence needs to be elaborated to make it clear what you mean (both here and the other place you've pasted the same text).

Also, as another aside, it would be nice to xref the other two TLV types that you reference.

### Section 6, no MRAI

You disallow MinRouteAdvertisementInterval. The real IGPs have various pacing parameters. I suppose you're just relying on TCP flow control to keep things from melting down? I don't have a very good feeling about it, though, because you can still blast a whole lot of noise down a well-tuned TCP connection, all the more so because you have advice elsewhere telling implementors to flood, then evaluate, and to prioritize BGP SPF.

Help me feel better about this, please.

### Section 6.1.1, withdrawing NLRI

  *  If self-originated Link or Prefix NLRI is received and the Link or
      Prefix NLRI is no longer being advertised by the local node, the
      NLRI is considered stale and is withdrawn using the standard BGP
      Update message Withdrawn Routes encodings [RFC4271].

First of all, you have the wrong cite: you can't use the RFC 4271 withdrawn routes encoding, that's only for IPv4 unicast. You mean [RFC4760].

But the more concerning thing here is that even if you use the right encoding, it won't work. If you send a withdrawal for a route you aren't advertising, that withdrawal is a no-op. It won't do anything. I think in this case you have to us the procedure you've defined in Section 6.5.1 instead.

### Section 6.1.1, how does the node even come to see this stuff?

  The above actions are performed immediately when the first instance
  of a newer self-originated NLRI is received.
 
With normal BGP, it's common to suppress sending routes back to their originator. This is done in both EBGP (if I notice the route I'm about to send you has your AS in the path, maybe I won't send it to you) and IBGP (if I notice your BGP Identifier in the ORIGINATOR_ID, maybe I won't send it to you).

If such procedures are used with BGP-LS-SPF, it would presumably prevent Section 6.1.1 from ever operating. In the worst case, it enables a nasty attack, where the attacker supersedes the sequence number of the legitimate route and prevents the "victim" from ever seeing the attacker's route. This is analogous to BGP path poisoning.

This seems problematic, let's discuss.

### Section 7.1, conflict with RFC 9552

  When a BGP SPF speaker receives a BGP Update that does not contain
  any BGP-LS Attribute, then a BGP SPF speaker MUST consider the
  corresponding NLRI as malformed and MUST handle it as 'Treat-as-
  withdraw' [RFC7606].  An implementation SHOULD log an error (subject
  to rate-limiting) for further analysis.

Whereas RFC 9552 says (Section 8.2.2):

  When a BGP Speaker receives an UPDATE message with Link-State NLRI(s)
  in the MP_REACH_NLRI but without the BGP-LS Attribute, it is most
  likely an indication that a BGP Speaker preceding it has performed
  the 'Attribute Discard' fault handling.  An implementation SHOULD
  preserve and propagate the Link-State NLRIs, unless denied by local
  policy, in such an UPDATE message so that the BGP-LS Consumers can
  detect the loss of link-state information for that object and not
  assume its deletion/withdrawal.  This also makes it possible for a
  network operator to trace back to the BGP-LS Propagator that detected
  the fault with the BGP-LS Attribute.

The rationale in RFC 9552 seems reasonable enough, maybe you should just stick with the standard. If you really do want to diverge from it, I think you need to indicate that you're doing so.

[Ballot comment]
## COMMENT

### Section 1, BGP-LS isn't a "protocol"

  This document leverages both the BGP protocol [RFC4271] and the BGP-
  LS [RFC9552] protocols.
 
Perhaps,

  This document leverages both the BGP protocol [RFC4271] and its BGP-
  LS [RFC9552] extension.
 
### Section 1.1, "Prefix NLRI"

You talk about the "Prefix NLRI" all over the place. I suppose what you mean by "Prefix NLRI" is "either the IPv4 Topology Prefix NLRI or the IPv6 Topology Prefix NLRI, defined in RFC 9552". If this is right, please add something like it to your terminology section. If this is wrong, please help me understand.

### Section 1.1, Link-State NLRI

In three places you reference "Link-State NLRI". Are these the same as "BGP-LS-SPF NLRI"? (I guess so.) Ideally, just change those three places to use the term you've already defined. If you don't want to do that, please add a definition.

### Section 1.1, BGP SPF

I guess you've decided to call this thing "BGP SPF" and not "LSVR". That being the case, I think you should supply a definition that says so clearly. The document title is "BGP Link-State Shortest Path First (SPF) Routing" which doesn't lend itself obviously to abbreviation as "BGP SPF".

It's also a little troubling that this is sometimes called "BGP-LS-SPF" and sometimes "BGP SPF". Is there a solid distinction between the two? If not, can you settle on one or the other?

### Section 1.2, "distance-vector"

The generally accepted way to describe BGP is as a "path-vector" protocol, not "distance-vector" as you do two places in this section. (I agree one is a special case of the other, but still.)

### Section 4.3, Y U no BFD?

In Section 4.2, you write "The BFD protocol [RFC5880] is RECOMMENDED for liveness detection." But in Section 4.3, you are neutral about liveness detection: "BGP-LS-SPF Link NLRI is advertised as long as the corresponding link is considered up as per the chosen liveness detection mechanism."

If you mean for BFD to be RECOMMENDED for RR/Controller deployments as well, please say so. If you mean for the choice of liveness detection to be completely out of scope for such deployments, also please say so.

### Section 4.3, redundant sentences

In the first paragraph you say "The BGP-LS-SPF Link NLRI is advertised as long as [...] optionally, the EoR Marker has been received as described in the Section 5.3." Then, the second paragraph says, "An End-of-RIB (EoR) Marker Section 5.3 for the BGP-LS-SPF SAFI MAY be required from a peer prior to advertising the BGP-LS Link NLRI for the corresponding link(s) to that peer."

As far as I can tell you don't need the second paragraph.

### Section 4.3, our ideas of normal are different

You write, "Normally, the route-reflectors or controller BGP sessions would be on directly-connected links to avoid dependence on another routing protocol for session connectivity."

To my knowledge, in normal BGP deployments, one does not assume RRs/controllers to be directly connected. Again, to the best of my knowledge, BGP-LS isn't widely enough deployed to say anything meaningful about what norms exist for its deployment. Perhaps you mean "Ideally"?

### Section 4.3, I don't think lsvr-applicability covers that

You write, "The number of BGP sessions is dependent on the redundancy requirements and the stability of the BGP sessions. This is discussed in greater detail in [I-D.ietf-lsvr-applicability]."

I don't think it is discussed there, either in greater detail or at all. Maybe drop that sentence? (Or point me to what I missed.)

### Section 4.3

It took me a while to suss out this paragraph:

  The controller may use constraints to determine when to advertise
  BGP-LS-SPF NLRI for BGP-LS peers.  For example, a controller may
  delay advertisement until the EoR marker Section 5.3 has been
  received from both BGP peers and the BGP-LS Link NLRI for the link(s)
  between the two nodes have been received from both BGP peers.

It would have helped me to insert "of a link between two peers" after "delay advertisement".

### Section 5.2.2.2

I found "A single TLV type is shared by the Node, Link, and Prefix NLRI. The TLV type is 1184" to be clearer and more helpful than "The BGP-LS-SPF Node NLRI Attribute SPF Status TLV, Link NLRI Attribute SPF Status TLV, and Prefix NLRI Attribute SPF Status TLV use the same TLV Type (1184)." In any case, the two are redundant with each other. I'd be happy to see you stick with the former and eliminate the latter in all three relevant subsections (and that might help fix my DISCUSS as well).

### Section 5.2.1.1 and elsewhere

In three places you talk about how an "update is propagated". BGP doesn't propagate updates. It propagates *routes*. Maybe you don't want to talk about "routes" because of how you're (ab)using the protocol, but it's just not accurate to use "update" as a replacement.

### Section 5.2.4, BGP-LS Attribute TLV

When you write "BGP-LS Attribute TLV" in the first paragraph, you mean "BGP-LS Attribute Sequence Number TLV", right?

### Section 5.3, EoR handling seems underspecified

It's normal to say something about a timeout if you've decided you're going to wait for EoR. On the other hand, if you mean an implementation should not have a timeout and should wait forever, you definitely should say that!

### Section 5.4 and elsewhere, NEXT_HOP

You keep talking about NExT_HOP and the NEXT_HOP attribute. Your routes don't have a NEXT_HOP attribute. RFC 4760, which you rely on, says:

  An UPDATE message that carries no NLRI, other than the one encoded in
  the MP_REACH_NLRI attribute, SHOULD NOT carry the NEXT_HOP attribute.

RFC 9552 gets this right. Please review every place you use "NEXT_HOP" and make the necessary changes.

### Section 6, SPF speaker's peer

Your first paragraph is a summary of the standard BGP decision process. It refers to the "BGP SPF speaker's peer". I think you just mean "BGP speaker's peer" since by definition, you're summarizing the behavior of a normal BGP implementation.

### Section 6.1, rules no longer apply

This sentence made my eyes cross:

  The rules for all BGP-LS-SPF NLRIs selection for phase 1 of the BGP
  decision process, section 9.1.1 [RFC4271], no longer apply.

Maybe you mean,

  For all BGP-LS-SPF NLRIs, the selection rules for phase 1 of the BGP
  decision process, section 9.1.1 [RFC4271], no longer apply.

### Section 6.1, i.e. or e.g.?

  When a BGP SPF speaker completely loses its sequence number state,
  i.e., due to a cold start, or in the unlikely possibility that 64-bit
  sequence number wraps, the BGP routing domain will still converge.
 
I think you must mean e.g., right?

### Section 6.3, step 4, or step 5?

          the scope if this document.  Nonetheless, step 4 (below)
          includes a set of recommendations in case such a limit is
          encountered.  Weighted Unequal Cost Multi-Path routes are out
          of scope as well.

I think you mean "step 5 (below)", right?

### Section 6.3, paste error?

              -  For unnumbered links to match during the IPv4 or IPv6
                SPF computation, Current-Link and Remote-Link's Address
                Family Link Descriptor TLV must match the address
                family of the IPv4 or IPv6 SPF computation, the
                Current-Link's Remote Identifier MUST the Remote-Link's
                Local Identifier/the Current-Link's Remote Identifier
                MUST match the Remote-Link's Local Identifier.  Since

Do you mean this?

              -  For unnumbered links to match during the IPv4 or IPv6
                SPF computation, Current-Link and Remote-Link's Address
                Family Link Descriptor TLV must match the address
                family of the IPv4 or IPv6 SPF computation, the
                Current-Link's Remote Identifier
                MUST match the Remote-Link's Local Identifier.  Since

### Section 6.5.1, what kind of priority?

This is too vague:

  Consequently, local link failures SHOULD always be given priority
  over updates in order to ensure the highest priority propagation and
  optimal convergence.
 
The key problems are, what kind of priority? And, what do you mean by "updates"? Both of these can mean so many things.

The subsequent paragraphs help untangle it, I guess you mean something like, "Consequently, it's advantageous to communicate local link failures as quickly as possible." I suggest some such kind of rewrite.

### Section 6.5.1, "with a BGP advertisement"

  With a BGP advertisement, the link would continue to be used until
  the last copy of the BGP-LS-SPF Link NLRI is withdrawn.
 
But your advertisements ARE BGP advertisements! So this is not right, as written. (Unless we want to admit that BGP SPF isn't BGP...)

Maybe something like,

  According to standard BGP procedures, the link would continue
  to be used until the last copy of the BGP-LS-SPF Link NLRI is
  withdrawn.
 
### Section 6.5.2, what if the session re-establishes?

This section defines something a little bit like one part of graceful restart, in that you tell the implementor to keep around stale routes for two seconds. Do you need considerations for any of the corner cases, for example, what if the session re-establishes before the routes are deleted?

### Section 7.4, loss of sync

It's kind of alarming that you throw this grenade and then run away, but anyway: why make this a MUST? One could imagine using some route-refresh variant, for instance. I'm not saying that's better, but I am saying that since you've clearly not finished thinking this through, it's maybe a little premature to say you MUST tear down the session, no debate.

### Section 8.2, that's not TBD, it's 1185

    | TBD1    | Address Family  | Section 5.2.2.1, RFCXXXX ([this |
    |          | Link Descriptor | document]).                    |

The registry says that's 1185, not TBD1.

[Ballot comment]

# Éric Vyncke, INT AD, comments for draft-ietf-lsvr-bgp-spf-43
CC @evyncke

Thank you for the work put into this document, even if it seems "weird" to my non-RTG mind to use BGP to convey link-state and to use these state for a SPF ;-)

Please find below one  some non-blocking COMMENT points (but replies would be appreciated even if only for my own education).

Special thanks to Ketan Talaulikar for the shepherd's detailed write-up including the WG consensus *but* and the justification of the intended status is rather weak.

I hope that this review helps to improve the document,

Regards,

-éric

## COMMENTS (non-blocking)

### Use of BGP transport for link-state routing

Take the following with a grain of salt, as I am not a routing expert... So, there is a 3rd link-state routing protocol in addition to OSPF and IS-IS... not a problem, but how is a link failure detected ? Is BFD a requirement for such a deployment (there is no quick hello messages in BGP AFAIK), BFD is only mentioned in section 4.2 but not in section 4.1.

How is TCP congestion (and the associated delay in sending link-state information) handled? I.e., all routers may not have the same view for a longer period of time than in traditional link-state IGP.

### MSDC acronym

I have often seen MSDC as "Massively Scalable Data Center" and not as `Massively Scaled Data Centers`. Perhaps a double check ?

### Abstract & section 1

`L3 routing` should rather be "IP routing" or "layer-3 routing".

### Section 1

s/high degree of Equal Cost Multi-Path (ECMPs)/high degree of Equal Cost Multi-Path (ECMPs) load-balancing/ ?

Should `LFA` be expanded before first use ?

### Section 4

Suggest adding one sentence about "The next sub-sections will describe several deployment models" or something similar.

### Section 4.2

The expansion of "EoR" appears after its first use.

### Section 4.3

This looks very similar to PCEP deployment model. Should there be a comparison ?

### Section 5.2.2

Are the local/remote IPv6 address global or link local ?

### Section 6.2

FYI (no need to reply), draft-chroboczek-intarea-v4-via-v6 is about having a next hop in a different address family.

### Section 8

There are two different `TBD` code points defined in this I-D, please use "TBD1" and "TBD2" to avoid any ambiguity.

### Section

Should this rather be a "MUST" in `it is RECOMMENDED that the TCP Authentication Option (TCP-AO)` ? Especially, since nothing is written in the I-D about using the Generalised TTL Security Mechanism making easier for a remote attacker to inject in a TCP session (assuming sequence number are known).

[Ballot comment]
# Internet AD comments for draft-ietf-lsvr-bgp-spf-41
CC @ekline

* comment syntax:
  - https://github.com/mnot/ietf-comments/blob/main/format.md

* "Handling Ballot Positions":
  - https://ietf.org/about/groups/iesg/statements/handling-ballot-positions/

## Comments

### S6.2

* "is an implementation matter" ->
  "is an implementation and/or policy matter"  (just a suggestion)

## Nits

### S1.2

* "100s or 1000s prefixes" -> "100s or 1000s of prefixes"

* "verification of the whether or not to advertise" ->
  "verification of whether or not to advertise"

### S3

* "to insure backward compatibility" ->
  "to ensure backward compatibility"

### S4.2, S4.3

* "liveliness" -> "liveness" (RFC 5880 only speaks of "liveness")

### S5.2.2

* "When 0 is advertised and there parallel unnumbered links" ->
  "When 0 is advertised and there are parallel unnumbered links"

### S5.2.4

* s/insure/ensure/

  (in general throughout the doc, as well)

[Ballot comment]
Thanks to David Mandelberg for his secdir review.

The tiniest of nits, and only because I happened to see it:
Section 4, para2, sentence 1:  nit:  'is up the operator' should be 'is up to the operator'.

IESG/Authors/WG Chairs:

IANA has completed its review of draft-ietf-lsvr-bgp-spf-39. If any part of this review is inaccurate, please let us know.

IANA has a question about one of the actions requested in the IANA Considerations section of this document.

IANA understands that, upon approval of this document, there are eight actions which we must complete.

First, in the SAFI Values registry in the Subsequent Address Family Identifiers (SAFI) Parameters registry group located at:

https://www.iana.org/assignments/safi-namespace/

the registration for:

Value: 80
Description: BGP-LS-SPF

will have its reference changed to [ RFC-to-be ].

Second, in the BGP-LS NLRI and Attribute TLVs registry on the Border Gateway Protocol - Link State (BGP-LS) Parameters registry group located at:

https://www.iana.org/assignments/bgp-ls-parameters/

the three assignments for:

TLV Code Point: 1180
Description: TLV types SPF Capability

TLV Code Point: 1182
Description: IPv4 Prefix Length

TLV Code Point: 1183
Description: IPv6 Prefix Length

will be removed. We are clarifying with the experts on whether we should list these values are DEPRECATED or to remove them from the registry entirely. We will mark this document as OK once this expert review been completed.

Third, also in the BGP-LS NLRI and Attribute TLVs registry in the Border Gateway Protocol - Link State (BGP-LS) Parameters registry group located at:

https://www.iana.org/assignments/bgp-ls-parameters/

the two assignments for:

TLV Code Point: 1181
Description: Sequence Number

TLV Code Point: 1184
Description: SPF Status

will have their references updated. The reference for TLV Code Point 1181 will be [ RFC-to-be; Section 5.2.4 ]. The reference for TLV Code Point 1184 will be [ RFC-to-be; Section 5.2.1.1, Section 5.2.2.2, Section 5.2.3.1 ]

Fourth, also in the BGP-LS NLRI and Attribute TLVs registry on the Border Gateway Protocol - Link State (BGP-LS) Parameters registry group located at:

https://www.iana.org/assignments/bgp-ls-parameters/

a single new registration will me made as follows:

TLV Code Point: [ TBD-at-Registration ]
Description: Address Family Link Descriptor
Reference: [ RFC-to-be ]

As this document requests registrations in an Expert Review or Specification Required (see RFC 8126) registry, we have completed the required Expert Review via a separate request. We have also already added this assignment to the registry at the expert's request.

Fifth, a new registry group will be created in the IANA Matrix called BGP SPF. The new registry group will have a reference that points to [ RFC-to-be ]. The new registry group will be linked from:

https://www.iana.org/protocols

IANA Question --> Would it be acceptable to name the new registry group BGP Shortest Path First for ease of identification?

Sixth, a new registry is to be created called BBGP-LS-SPF Prefix NLRI Attribute SPF Status TLV Status. The new registry is to be created in the new registry group created by IANA Action five, above. The new registry is to be managed via IETF Review as defined in RFC8126. There are initial registrations in the new registry as follows:

Value Description Reference
-----+-----------+-------------
0 Reserved [ RFC-to-be ]
1 Link unreachable with respect to BGP SPF [ RFC-to-be ]
3-254 Unassigned
255 Reserved [ RFC-to-be ]

Seventh, another new registry is to be created called BGP-LS-SPF Link NLRI Attribute SPF Status TLV Status. The new registry is to be created in the new registry group created by IANA Action five, above. The new registry is to be managed via IETF Review as defined in RFC8126. There are initial registrations in the new registry as follows:

Value Description Reference
-----+-----------+-------------
0 Reserved [ RFC-to-be ]
1 Prefix unreachable with respect to BGP SPF [ RFC-to-be ]
3-254 Unassigned
255 Reserved [ RFC-to-be ]

Eighth, in the BGP Error (Notification) Codes registry in the Border Gateway Protocol (BGP) Parameters registry group located at:

https://www.iana.org/assignments/bgp-parameters/

a single new registration will be made as follows:

Value: [ TBD-at-Registration ]
Name: Loss of LSDB Synchronization
Reference: [ RFC-to-be ]

We understand that these are the only actions required to be completed upon approval of this document.

NOTE: The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Sr. Specialist

The following Last Call announcement was sent out (ends 2024-12-10):

From: The IESG
To: IETF-Announce
CC: Gunter Van de Velde , aretana.ietf@gmail.com, draft-ietf-lsvr-bgp-spf@ietf.org, james.n.guichard@futurewei.com, ketant.ietf@gmail.com, lsvr-chairs@ietf.org, lsvr@ietf.org, victor@jvknet.com
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (BGP Link-State Shortest Path First (SPF) Routing) to Proposed Standard


The IESG has received a request from the Link State Vector Routing WG (lsvr)
to consider the following document: - 'BGP Link-State Shortest Path First
(SPF) Routing'
  as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2024-12-10. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

Abstract


  Many Massively Scaled Data Centers (MSDCs) have converged on
  simplified L3 routing.  Furthermore, requirements for operational
  simplicity has led many of these MSDCs to converge on BGP as their
  single routing protocol for both their fabric routing and their Data
  Center Interconnect (DCI) routing.  This document describes
  extensions to BGP to use BGP Link-State distribution and the Shortest
  Path First (SPF) algorithm.  In doing this, it allows BGP to be
  efficiently used as both the underlay protocol and the overlay
  protocol in MSDCs.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-lsvr-bgp-spf/



No IPR declarations have been submitted directly on this I-D.


The document contains these normative downward references.
See RFC 3967 for additional information:
    rfc4272: BGP Security Vulnerabilities Analysis (Informational - Internet Engineering Task Force (IETF) stream)
    rfc4593: Generic Threats to Routing Protocols (Informational - Internet Engineering Task Force (IETF) stream)
    rfc6952: Analysis of BGP, LDP, PCEP, and MSDP Issues According to the Keying and Authentication for Routing Protocols (KARP) Design Guide (Informational - Internet Engineering Task Force (IETF) stream)
    rfc7938: Use of BGP for Routing in Large-Scale Data Centers (Informational - Internet Engineering Task Force (IETF) stream)
    draft-ietf-lsvr-applicability: Usage and Applicability of Link State Vector Routing in Data Centers (None - Internet Engineering Task Force (IETF) stream)
    draft-psarkar-lsvr-bgp-spf-impl: BGP Shortest Path Routing Extension Implementation Report (None -  stream)

This shepherd write-up is per RFC 4858 and based on the template published
on the IESG site. This version is dated 4 July 2022.

Document History

1) Does the working group (WG) consensus represent the strong concurrence of a
few individuals, with others being silent, or did it reach broad agreement?

The document has gone through multiple WGLCs:
- 1st in Oct 2019
- 2nd in Feb 2023
- 3rd in Oct 2024 (the current one)

Over these WGLCs while the participation has progressively reduced, taken all
together the document does represent broad agreement in the WG.

2) Was there controversy about particular points, or were there decisions where
the consensus was particularly rough?

No. The document has undergone multiple revisions to iron out comments
including some that had more than one way of getting addressed.

3) Has anyone threatened an appeal or otherwise indicated extreme discontent? If
so, please summarize the areas of conflict in separate email messages to the
responsible Area Director. (It should be in a separate email because this
questionnaire is publicly available.)

No

4) For protocol documents, are there existing implementations of the contents of
the document? Have a significant number of potential implementers indicated
plans to implement? Are any existing implementations reported somewhere,
either in the document itself (as RFC 7942 recommends) or elsewhere
(where)?

Implementations of an earlier version of the draft have been reported in a
separate individual document.
https://datatracker.ietf.org/doc/draft-psarkar-lsvr-bgp-spf-impl/

The latest version of the document still holds the same core protocol
specification as implemented. There have been some aspects removed (which were
not implemented) and many clarifications.

The implementers in the WG have shared that their implementations would be
updated to reflect the latest specification upon publication as RFC.

Additional Reviews

5) Do the contents of this document closely interact with technologies in other
IETF working groups or external organizations, and would it therefore benefit
from their review? Have those reviews occurred? If yes, describe which
reviews took place.

Yes. Since this is a BGP extension, the document has been cross-posted to the
IDR WG for reviews during the WGLCs.


6) Describe how the document meets any required formal expert review criteria,
such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

not applicable

7) If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation tools for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module
comply with the Network Management Datastore Architecture (NMDA) as specified
in RFC 8342?

not applicable - note that the corresponding YANG module is being worked on in
a separate document by the WG

8) Describe reviews and automated checks performed to validate sections of the
final version of the document written in a formal language, such as XML code,
BNF rules, MIB definitions, CBOR's CDDL, etc.

Has been run clean through idnits; others don't apply
Document Shepherd Checks

9) Based on the shepherd's review of the document, is it their opinion that this
document is needed, clearly written, complete, correctly designed, and ready
to be handed off to the responsible Area Director?

Yes

10) Several IETF Areas have assembled lists of common issues that their
reviewers encounter. For which areas have such issues been identified
and addressed? For which does this still need to happen in subsequent
reviews?

RTGDIR and OPSDIR reviews have happened

11) What type of RFC publication is being requested on the IETF stream (Best
Current Practice, Proposed Standard, Internet Standard,
Informational, Experimental or Historic)? Why is this the proper type
of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard - this is reflected in the datatracker.

The WG was explicitly polled on this during the most recent WGLC and there was
significant support for publication as Proposed Standard and there was no
opposition. There exist implementations as well.

12) Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? To
the best of your knowledge, have all required disclosures been filed? If
not, explain why. If yes, summarize any relevant discussion, including links
to publicly-available messages when applicable.

No IPR has been declared on this document.

Yes - all authors have responded to the previous and the latest IPR poll
during the WGLC. Most contributors have also responded to the latest IPR poll.
There are a couple of contributors listed (Abhay & Venu) that do not seem to
be active during the recent years but they had responded to IPR polls at
previous WGLCs.

13) Has each author, editor, and contributor shown their willingness to be
listed as such? If the total number of authors and editors on the front page
is greater than five, please provide a justification.

Yes and not applicable

14) Document any remaining I-D nits in this document. Simply running the idnits
tool is not enough; please review the "Content Guidelines" on
authors.ietf.org. (Also note that the current idnits tool generates
some incorrect warnings; a rewrite is underway.)

None

15) Should any informative references be normative or vice-versa? See the IESG
Statement on Normative and Informative References.

None

16) List any normative references that are not freely available to anyone. Did
the community have sufficient access to review any such normative
references?

None

17) Are there any normative downward references (see RFC 3967 and BCP
97) that are not already listed in the DOWNREF registry? If so,
list them.

None

18) Are there normative references to documents that are not ready to be
submitted to the IESG for publication or are otherwise in an unclear state?
If so, what is the plan for their completion?

None

19) Will publication of this document change the status of any existing RFCs? If
so, does the Datatracker metadata correctly reflect this and are those RFCs
listed on the title page, in the abstract, and discussed in the
introduction? If not, explain why and point to the part of the document
where the relationship of this document to these other RFCs is discussed.

No

20) Describe the document shepherd's review of the IANA considerations section,
especially with regard to its consistency with the body of the document.
Confirm that all aspects of the document requiring IANA assignments are
associated with the appropriate reservations in IANA registries. Confirm
that any referenced IANA registries have been clearly identified. Confirm
that each newly created IANA registry specifies its initial contents,
allocations procedures, and a reasonable name (see RFC 8126).

The allocation scheme is Expert Review for the Node SPF Status but IETF Review
for the Link and Prefix SPF Status as per authors choice. Other things are in
order.

21) List any new IANA registries that require Designated Expert Review for
future allocations. Are the instructions to the Designated Expert clear?
Please include suggestions of designated experts, if appropriate.

Confirmed that this is in order.

This shepherd write-up is per RFC 4858 and based on the template published
on the IESG site. This version is dated 4 July 2022.

Document History

1) Does the working group (WG) consensus represent the strong concurrence of a
few individuals, with others being silent, or did it reach broad agreement?

The document has gone through multiple WGLCs:
- 1st in Oct 2019
- 2nd in Feb 2023
- 3rd in Oct 2024 (the current one)

Over these WGLCs while the participation has progressively reduced, taken all
together the document does represent broad agreement in the WG.

2) Was there controversy about particular points, or were there decisions where
the consensus was particularly rough?

No. The document has undergone multiple revisions to iron out comments
including some that had more than one way of getting addressed.

3) Has anyone threatened an appeal or otherwise indicated extreme discontent? If
so, please summarize the areas of conflict in separate email messages to the
responsible Area Director. (It should be in a separate email because this
questionnaire is publicly available.)

No

4) For protocol documents, are there existing implementations of the contents of
the document? Have a significant number of potential implementers indicated
plans to implement? Are any existing implementations reported somewhere,
either in the document itself (as RFC 7942 recommends) or elsewhere
(where)?

Implementations of an earlier version of the draft have been reported in a
separate individual document.
https://datatracker.ietf.org/doc/draft-psarkar-lsvr-bgp-spf-impl/

The latest version of the document still holds the same core protocol
specification as implemented. There have been some aspects removed (which were
not implemented) and many clarifications.

The implementers in the WG have shared that their implementations would be
updated to reflect the latest specification upon publication as RFC.

Additional Reviews

5) Do the contents of this document closely interact with technologies in other
IETF working groups or external organizations, and would it therefore benefit
from their review? Have those reviews occurred? If yes, describe which
reviews took place.

Yes. Since this is a BGP extension, the document has been cross-posted to the
IDR WG for reviews during the WGLCs.


6) Describe how the document meets any required formal expert review criteria,
such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

not applicable

7) If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation tools for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module
comply with the Network Management Datastore Architecture (NMDA) as specified
in RFC 8342?

not applicable - note that the corresponding YANG module is being worked on in
a separate document by the WG

8) Describe reviews and automated checks performed to validate sections of the
final version of the document written in a formal language, such as XML code,
BNF rules, MIB definitions, CBOR's CDDL, etc.

Has been run clean through idnits; others don't apply
Document Shepherd Checks

9) Based on the shepherd's review of the document, is it their opinion that this
document is needed, clearly written, complete, correctly designed, and ready
to be handed off to the responsible Area Director?

Yes

10) Several IETF Areas have assembled lists of common issues that their
reviewers encounter. For which areas have such issues been identified
and addressed? For which does this still need to happen in subsequent
reviews?

RTGDIR and OPSDIR reviews have happened

11) What type of RFC publication is being requested on the IETF stream (Best
Current Practice, Proposed Standard, Internet Standard,
Informational, Experimental or Historic)? Why is this the proper type
of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard - this is reflected in the datatracker.

The WG was explicitly polled on this during the most recent WGLC and there was
significant support for publication as Proposed Standard and there was no
opposition. There exist implementations as well.

12) Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? To
the best of your knowledge, have all required disclosures been filed? If
not, explain why. If yes, summarize any relevant discussion, including links
to publicly-available messages when applicable.

No IPR has been declared on this document.

Yes - all authors have responded to the previous and the latest IPR poll
during the WGLC. Most contributors have also responded to the latest IPR poll.
There are a couple of contributors listed (Abhay & Venu) that do not seem to
be active during the recent years but they had responded to IPR polls at
previous WGLCs.

13) Has each author, editor, and contributor shown their willingness to be
listed as such? If the total number of authors and editors on the front page
is greater than five, please provide a justification.

Yes and not applicable

14) Document any remaining I-D nits in this document. Simply running the idnits
tool is not enough; please review the "Content Guidelines" on
authors.ietf.org. (Also note that the current idnits tool generates
some incorrect warnings; a rewrite is underway.)

None

15) Should any informative references be normative or vice-versa? See the IESG
Statement on Normative and Informative References.

None

16) List any normative references that are not freely available to anyone. Did
the community have sufficient access to review any such normative
references?

None

17) Are there any normative downward references (see RFC 3967 and BCP
97) that are not already listed in the DOWNREF registry? If so,
list them.

None

18) Are there normative references to documents that are not ready to be
submitted to the IESG for publication or are otherwise in an unclear state?
If so, what is the plan for their completion?

None

19) Will publication of this document change the status of any existing RFCs? If
so, does the Datatracker metadata correctly reflect this and are those RFCs
listed on the title page, in the abstract, and discussed in the
introduction? If not, explain why and point to the part of the document
where the relationship of this document to these other RFCs is discussed.

No

20) Describe the document shepherd's review of the IANA considerations section,
especially with regard to its consistency with the body of the document.
Confirm that all aspects of the document requiring IANA assignments are
associated with the appropriate reservations in IANA registries. Confirm
that any referenced IANA registries have been clearly identified. Confirm
that each newly created IANA registry specifies its initial contents,
allocations procedures, and a reasonable name (see RFC 8126).

The allocation scheme is Expert Review for the Node SPF Status but IETF Review
for the Link and Prefix SPF Status as per authors choice. Other things are in
order.

21) List any new IANA registries that require Designated Expert Review for
future allocations. Are the instructions to the Designated Expert clear?
Please include suggestions of designated experts, if appropriate.

Confirmed that this is in order.

This shepherd write-up is per RFC 4858 and based on the template published
on the IESG site. This version is dated 4 July 2022.

Document History

1) Does the working group (WG) consensus represent the strong concurrence of a
few individuals, with others being silent, or did it reach broad agreement?

The document has gone through multiple WGLC:
- 1st in Oct 2019
- 2nd in Feb 2023
- 3rd in Oct 2024 (the current one)

Over these WGLCs the participation has progressively reduced. Taken all
together the document does represent broad agreement in the WG.

2) Was there controversy about particular points, or were there decisions where
the consensus was particularly rough?

No. The document has undergone multiple revisions to iron out comments
including some that had more than one way of gettng addressed.

3) Has anyone threatened an appeal or otherwise indicated extreme discontent? If
so, please summarize the areas of conflict in separate email messages to the
responsible Area Director. (It should be in a separate email because this
questionnaire is publicly available.)

No

4) For protocol documents, are there existing implementations of the contents of
the document? Have a significant number of potential implementers indicated
plans to implement? Are any existing implementations reported somewhere,
either in the document itself (as RFC 7942 recommends) or elsewhere
(where)?

Implementations of an earlier version of the draft have been reported in a
separate individual document and referenced in this document.
https://datatracker.ietf.org/doc/draft-psarkar-lsvr-bgp-spf-impl/

The latest version of the document still holds the same core protocol
specification as implemented. There have been some aspects removed (which were
not implemented) and many clarifications.

The implementers in the WG have shared that their implementations would be
updated to reflect the last specification upon publication as RFC.

Additional Reviews

5) Do the contents of this document closely interact with technologies in other
IETF working groups or external organizations, and would it therefore benefit
from their review? Have those reviews occurred? If yes, describe which
reviews took place.

Yes. Since this is a BGP extension, the document has been cross-posted to the
IDR WG for reviews during the WGLCs.


6) Describe how the document meets any required formal expert review criteria,
such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

not applicable

7) If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation tools for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module
comply with the Network Management Datastore Architecture (NMDA) as specified
in RFC 8342?

not applicable - note that the corresponding YANG module is being worked on in
a separate document by the WG

8) Describe reviews and automated checks performed to validate sections of the
final version of the document written in a formal language, such as XML code,
BNF rules, MIB definitions, CBOR's CDDL, etc.

Has been run clean through idnits

Document Shepherd Checks

9) Based on the shepherd's review of the document, is it their opinion that this
document is needed, clearly written, complete, correctly designed, and ready
to be handed off to the responsible Area Director?

Yes

10) Several IETF Areas have assembled lists of common issues that their
reviewers encounter. For which areas have such issues been identified
and addressed? For which does this still need to happen in subsequent
reviews?

RTGDIR and OPSDIR reviews have happened

11) What type of RFC publication is being requested on the IETF stream (Best
Current Practice, Proposed Standard, Internet Standard,
Informational, Experimental or Historic)? Why is this the proper type
of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard - this is reflected in the datatracker.

The WG was explicitly polled on this during the most recent WGLC and there was
significant support for publication as Proposed Standard and there was no
opposition. There exists implementations as well.

12) Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? To
the best of your knowledge, have all required disclosures been filed? If
not, explain why. If yes, summarize any relevant discussion, including links
to publicly-available messages when applicable.

No IPR has been declared on this document.

Yes - all authors have responded to the previous and the latest IPR poll
during the WGLC. Most contributors have also responded to the latest IPR poll.
There are a couple of contributors listed that do not seem to be active during
the recent years but they had responded to IPR polls at previous WGLCs.

13) Has each author, editor, and contributor shown their willingness to be
listed as such? If the total number of authors and editors on the front page
is greater than five, please provide a justification.

Yes and not applicable

14) Document any remaining I-D nits in this document. Simply running the idnits
tool is not enough; please review the "Content Guidelines" on
authors.ietf.org. (Also note that the current idnits tool generates
some incorrect warnings; a rewrite is underway.)

None

15) Should any informative references be normative or vice-versa? See the IESG
Statement on Normative and Informative References.

None

16) List any normative references that are not freely available to anyone. Did
the community have sufficient access to review any such normative
references?

None

17) Are there any normative downward references (see RFC 3967 and BCP
97) that are not already listed in the DOWNREF registry? If so,
list them.

None

18) Are there normative references to documents that are not ready to be
submitted to the IESG for publication or are otherwise in an unclear state?
If so, what is the plan for their completion?

None

19) Will publication of this document change the status of any existing RFCs? If
so, does the Datatracker metadata correctly reflect this and are those RFCs
listed on the title page, in the abstract, and discussed in the
introduction? If not, explain why and point to the part of the document
where the relationship of this document to these other RFCs is discussed.

No

20) Describe the document shepherd's review of the IANA considerations section,
especially with regard to its consistency with the body of the document.
Confirm that all aspects of the document requiring IANA assignments are
associated with the appropriate reservations in IANA registries. Confirm
that any referenced IANA registries have been clearly identified. Confirm
that each newly created IANA registry specifies its initial contents,
allocations procedures, and a reasonable name (see RFC 8126).

Comments yet to be resolved

21) List any new IANA registries that require Designated Expert Review for
future allocations. Are the instructions to the Designated Expert clear?
Please include suggestions of designated experts, if appropriate.

Comments yet to be resolved

Notification list changed to Gunter Van de Velde <gunter.van_de_velde@nokia.com>, aretana.ietf@gmail.com, victor@jvknet.com, ketant.ietf@gmail.com from Gunter Van de Velde <gunter.van_de_velde@nokia.com>, aretana.ietf@gmail.com, victor@jvknet.com because the document shepherd was set

- Abstract:

Change layer 3 routing to "layer-3 routing" as typically it is hyphenated. Also used in the introduction so change throughout the document.

- Introduction:

BGP-LS [I-D.ietf-idr-rfc7752bis] protocols -> change to 'protocol' (BGP-LS is a single protocol not a suite of protocols as the sentence suggests).

- Section 2:

First paragraph text "any error handling defined in the [RFC4271] and [RFC7606]" - remove "the" in this sentence.

Third paragraph text "Section 9 of [RFC4271] defines the decision process" - it is actually Section 9.1

- Section 3:

  The rules for setting the NLRI next-hop path attribute for the BGP-
  LS-SPF SAFI follow the BGP-LS SAFI as specified in section 3.4 of
  [I-D.ietf-idr-rfc7752bis].

There is no section 3.4 in ietf-idr-rfc7752bis. Please correct this reference. Should it be section 5.5?

- Section 4.1:

Second paragraph text "advertising the BGP-LS Link NLRI for to peer" - sentence does not make grammatical sense please correct the end of the sentence.

- Section 5.1.1:

  If a mandatory TLV is not specified, the NLRI is
  not used in the BGP SPF route calculation.  All the other TLVs are
  considered as an optional TLVs.

If a mandatory TLV is not specificed then would this be considered a misconfiguration or implementation bug? I would like to understand how that might happen and also what is the router supposed to do other than not consider the NLRI in the SPF route calculation?

- Section 5.1.2:

This attribute
  is an optional, non-transitive BGP attribute that is used to carry
  link, node, and prefix properties and attributes.

if this is non-transitive it means it cannot be sent (flooded) to eBGP peers and yet the deployment models specifically allow the use of eBGP and iBGP. Is the intent to
redefine the transitive nature of the BGP-LS attribute and if so, this needs to be specifically stated.

- Section 5.2:

For Node NLRI and Link NLRI, this MUST be the direct protocol
  (4)

It might be clearer to put "For Node NLRI and link NLRI, this MUST be the direct protocol (value: 4)".

- Section 5.2.1.1:

An implementation MAY
  optionally log detection of a BGP node that has either not advertised
  the SPF capability TLV or is advertising the SPF capability TLV with
  an algorithm type other than 0.

The SPF capability TLV seems to be mandatory although the text does not specifically say it but implies it by saying "attribute TLV MUST be included". Please
clarify and add mandatory if necessary. Also, shouldn't the MAY be a MUST as otherwise, you could be calculating SPF without a node that you expect to be
included in the calculation?

- Section 5.2.1.2:

Third paragraph text "A BGP SPF speaker receiving a BGP Update containing a SPF Status TLV in the BGP-LS attribute [I-D.ietf-idr-rfc7752bis] with a value that is undefined values SHOULD.." - remove "values" from end of sentence (redundant text).

- Section 5.2.2:

Fourth paragraph text "MUST consider the received NLRI as a malformed.." - remove "a" from text.

- Section 5.2.2.1:

Third paragraph text "The maximum prefix-length is 32 bits for an IPv4 Prefix-Length TLV A prefix-length field and 128 bits for an IPv6 Prefix-Length TLV." looks malformed should "A prefix-length field" text in sentence be removed?

Third paragraph second sentence "A prefix-length field indicating a larger value is in error and the the corresponding.." - remove extra "the" in sentence.

Third paragraph third sentence " An implementation MAY log." - remove text as next sentence replaces it.

- Section 5.2.4:

  A BGP-LS Attribute TLV of the BGP-LS-SPF NLRI types is defined to
  assure the most recent version of a given NLRI is used in the SPF
  computation.  The Sequence-Number TLV is mandatory for BGP-LS-SPF
  NLRI.

Is this mandatory for all NLRI types or just Node NLRI?

- Section 5.2.4:

Add colon after "Sequence Number" in description of TLV.

- Section 6.1.1:

  *  If self-originated NLRI is received and the sequence number is
      more recent (i.e., greater than the local node's sequence number
      for the NLRI), the NLRI sequence number is advanced to one greater
      than the received sequence number and the NLRI is readvertised to
      all peers.

If the sequence number is higher than the local nodes sequence number then shouldn't this be treated as an error as someone (not the local node) has increased the sequence number - they should not be
doing that. If there is a reason why the sequence number CAN legitimately increase then that should be stated (I cannot think of an example where this is valid). Is this related to cold-start? If so please
make that clearer.

  *  If self-originated NLRI is received and the sequence number is the
      same as the local node's sequence number but the attributes
      differ, the NLRI sequence number is advanced to one greater than
      the received sequence number and the NLRI is readvertised to all
      peers.

How is it possible for the attributes of a self-originated NLRI to change? if this is valid then an example should be provided.

- Section 6.3:

      The CAN-LIST is typically implemented as a heap but other data
      structures have been used.

Probably better to say that other data structures MAY be used.

- Section 9:

The BGP-LS-SPF SAFI NLRI described in this document are
  typically advertised between EBGP or IBGP speakers under a single
  administrative domain.

how based on iBGP advertisement rules? how can an iBGP speaker flood NLRI to another iBGP speaker unless they are a route reflector?

Several editorial nits to be fixed please.

- Abstract:

Change layer 3 routing to "layer-3 routing" as typically it is hyphenated. Also used in introduction so change throughout document.

- Introduction:

BGP-LS [I-D.ietf-idr-rfc7752bis] protocols -> change to protocol (BGP-LS is a single protocol not a suite of protocols as the sentence suggests).

- Section 2:

- First paragraph text "any error handling defined in the [RFC4271] and [RFC7606]" - remove "the" in this sentence.
- Third paragraph text "Section 9 of [RFC4271] defines the decision process" - it is actually Section 9.1

- Section 4.1:

- Second paragraph text "advertising the BGP-LS Link NLRI for to peer" - sentence does not make grammatical sense please correct end of sentence.

- Section 4.3:

- reference to ietf-lsvr-applicability - should that document be processed at the same time as this one (?)

- Section 5.2.1.2:

- Third paragraph text "A BGP SPF speaker receiving a BGP Update containing a SPF Status TLV in the BGP-LS attribute [I-D.ietf-idr-rfc7752bis] with a
value that is undefined values SHOULD.." - remove "values" from end of sentence (redundant text).

- Section 5.2.2:

- Fourth paragraph text "MUST consider the received NLRI as a malformed.." - remove "a" from text.

- Section 5.2.2.1:

- Third paragraph text "The maximum prefix-length is 32 bits for an IPv4 Prefix-Length TLV A prefix-length field and 128 bits for an IPv6 Prefix-Length
TLV." looks malformed should "A prefix-length field" text in sentence be removed?
- Third paragraph second sentence "A prefix-length field indicating a larger value is in error and the the corresponding.." - remove extra "the" in sentence.
- Third paragraph third sentence " An implementation MAY log." - remove text as next sentence replaces it.

- Section 5.2.4:

- Add colon after "Sequence Number" in description of TLV.

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 15 February 2022.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?

Proposed Standard

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

1. Technical Summary:
Many Massively Scaled Data Centers (MSDCs) have converged on simplified layer 3 routing.  Furthermore, requirements for operational simplicity have led many of these MSDCs to converge on BGP as their single routing protocol for intra-fabric routing, inter-fabric routing and Data Center Interconnect (DCI) routing.  This draft describes a solution which leverages BGP Link-State distribution and the Shortest Path First (SPF) algorithm like Internal Gateway Protocols (IGPs) such as OSPF.
How is this done?

This document augments BGP-LS [RFC7752] by replacing its use of the existing Decision Process.  Rather than reusing the BGP-LS SAFI, the BGP-LS-SPF SAFI is introduced to insure backward compatibility.  The BGP Phase 1 and 2 decision functions of the Decision Process are replaced with the Shortest Path First (SPF) algorithm also known as the Dijkstra algorithm.  The BGP Phase 3 decision function is also simplified since it is no longer dependent on the previous phases.  This solution avails the benefits of both BGP and SPF-based IGPs.  These include TCP based flow-control, no periodic link-state refresh, and completely incremental NLRI advertisement.  These advantages can reduce the overhead in MSDCs where there is a high degree of Equal Cost Multi-Path (ECMPs) and the topology is very stable.  Additionally, using an SPF-based computation can support fast convergence and the computation of Loop-Free Alternatives (LFAs) [RFC5286] in the event of link failures.  Furthermore, a BGP based solution lends itself to multiple peering models including those incorporating route-reflectors [RFC4456] or controllers.

2. Review and Consensus
The LSVR WG enjoyed a turbulent startup period. The IDR WG and LSR WG handle routing for interdomain and intradomain, while LSVR is using foundational technology of both BGP and SPF based routing protocols. The IETF face-2-face meetings avoided timing overlap to allow IDR and LSR WG participants to voice the depths of their experience and technology authority. This contributed to develop and provide feedback upon the draft draft-ietf-lsvr-bgp-spf.

The draft went through few iterations of volunteer review cycles that have been tracked within the WG email list. In addition, the draft went through early directorate reviews. The original (2019) OPSDIR review executed upon an early version went well (state: READY), while RTGDIR (state: HAS ISSUES) review caused additional technology discussion resulting in the draft to be updated upon the feedback provided (See: https://mailarchive.ietf.org/arch/msg/lsvr/9z_KGdwqHlmhnzD5HWrarmlSroU/ ).  The document was re-reviewed in June 2021 with some additional concerns for consideration before publication.  These issues identified in the RTGDIR were addressed in the most recent version of publication.
The document went through a third WGLC in 2021 (May – June) and completed on June 17, 2021.

In addition, the LSVR chairs asked expert reviewers to provide feedback on the document, and those have been included and discussed on the WG mailing list.
The document went through three cycles of WGLC to finally result into current documentation status:

WGLC#1 on draft-ietf-lsvr-bgp-spf-03
Date: 3 December 2018 to 17 December 2018
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/-7zKGZ-PIXCNnpmxfEjHVSEUqXc/
WGLC#2 on draft-ietf-lsvr-bgp-spf-05
Date: 23 September 2019 – 7 October 2019
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/A066U6av_6--WDo7BRFswOtMea4/
WGLC#3 on draft-ietf-lsvr-bgp-spf-13
Date: 20 May 2021 – 17 June 2021
Reference: https://mailarchive.ietf.org/arch/browse/lsvr/?gbt=1&index=aQ9Ud_FjwiFpO7OGJnhcXgY0A4U
Current Implementations: https://datatracker.ietf.org/doc/html/draft-psarkar-lsvr-bgp-spf-impl-00
• Arrcus (March 2019): https://mailarchive.ietf.org/arch/msg/lsvr/OPB6pO_aKU8ty0A3PspSBTQyqXg/
• FRR Plans (June 2020): https://mailarchive.ietf.org/arch/msg/lsvr/wCXxSObjSy0Vih5SRS2PPbfacz8/

3. Intellectual Property
During the WGLC IPR calls were performed. No claims for IPR awareness were mentioned by WG members and neither by any of the participating document authors.

4. Other Points
No downward references
Request IANA to assign the BGP-LS/BGP-LS-SPF (AFI 16388 / SAFI TBD1) as described in [RFC4760].
From safi range [1-63] standards action: https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml
When this registry is modified, the YANG module [iana-routing-types] must be updated as defined in [RFC8294].
This draft also defines five attribute TLVs for BGP-LS NLRI from the "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" Registry
Expert review suggested by IANA:
https://www.iana.org/assignments/bgp-ls-parameters/bgp-ls-parameters.xhtml
The draft request IANA to assign types for the
• SPF capability TLV
• Sequence Number TLV
• IPv4 Link Prefix-Length TLV
• IPv6 Link Prefix-Length TLV
• SPF Status TLV.

WG Yang draft in progress found here - https://datatracker.ietf.org/doc/draft-ietf-lsvr-bgp-ls-yang/00/

5. Checklist
• This applicability for bgp-spf (https://www.ietf.org/id/draft-ietf-lsvr-bgp-spf-09.txt) draft is progressed in parallel with 'I-D.ietf-lsvr-applicability'

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 15 February 2022.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?

Proposed Standard

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

1. Technical Summary:
Many Massively Scaled Data Centers (MSDCs) have converged on simplified layer 3 routing.  Furthermore, requirements for operational simplicity have led many of these MSDCs to converge on BGP as their single routing protocol for intra-fabric routing, inter-fabric routing and Data Center Interconnect (DCI) routing.  This draft describes a solution which leverages BGP Link-State distribution and the Shortest Path First (SPF) algorithm like Internal Gateway Protocols (IGPs) such as OSPF.
How is this done?

This document augments BGP-LS [RFC7752] by replacing its use of the existing Decision Process.  Rather than reusing the BGP-LS SAFI, the BGP-LS-SPF SAFI is introduced to insure backward compatibility.  The BGP Phase 1 and 2 decision functions of the Decision Process are replaced with the Shortest Path First (SPF) algorithm also known as the Dijkstra algorithm.  The BGP Phase 3 decision function is also simplified since it is no longer dependent on the previous phases.  This solution avails the benefits of both BGP and SPF-based IGPs.  These include TCP based flow-control, no periodic link-state refresh, and completely incremental NLRI advertisement.  These advantages can reduce the overhead in MSDCs where there is a high degree of Equal Cost Multi-Path (ECMPs) and the topology is very stable.  Additionally, using an SPF-based computation can support fast convergence and the computation of Loop-Free Alternatives (LFAs) [RFC5286] in the event of link failures.  Furthermore, a BGP based solution lends itself to multiple peering models including those incorporating route-reflectors [RFC4456] or controllers.

2. Review and Consensus
The LSVR WG enjoyed a turbulent startup period. The IDR WG and LSR WG handle routing for interdomain and intradomain, while LSVR is using foundational technology of both BGP and SPF based routing protocols. The IETF face-2-face meetings avoided timing overlap to allow IDR and LSR WG participants to voice the depths of their experience and technology authority. This contributed to develop and provide feedback upon the draft draft-ietf-lsvr-bgp-spf.

The draft went through few iterations of volunteer review cycles that have been tracked within the WG email list. In addition, the draft went through early directorate reviews. The original (2019) OPSDIR review executed upon an early version went well (state: READY), while RTGDIR (state: HAS ISSUES) review caused additional technology discussion resulting in the draft to be updated upon the feedback provided (See: https://mailarchive.ietf.org/arch/msg/lsvr/9z_KGdwqHlmhnzD5HWrarmlSroU/ ).  The document was re-reviewed in June 2021 with some additional concerns for consideration before publication.  These issues identified in the RTGDIR were addressed in the most recent version of publication.
The document went through a third WGLC in 2021 (May – June) and completed on June 17, 2021.

In addition, the LSVR chairs asked expert reviewers to provide feedback on the document, and those have been included and discussed on the WG mailing list.
The document went through three cycles of WGLC to finally result into current documentation status:

WGLC#1 on draft-ietf-lsvr-bgp-spf-03
Date: 3 December 2018 to 17 December 2018
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/-7zKGZ-PIXCNnpmxfEjHVSEUqXc/
WGLC#2 on draft-ietf-lsvr-bgp-spf-05
Date: 23 September 2019 – 7 October 2019
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/A066U6av_6--WDo7BRFswOtMea4/
WGLC#3 on draft-ietf-lsvr-bgp-spf-13
Date: 20 May 2021 – 17 June 2021
Reference: https://mailarchive.ietf.org/arch/browse/lsvr/?gbt=1&index=aQ9Ud_FjwiFpO7OGJnhcXgY0A4U
Current Implementations: https://datatracker.ietf.org/doc/html/draft-psarkar-lsvr-bgp-spf-impl-00
• Arrcus (March 2019): https://mailarchive.ietf.org/arch/msg/lsvr/OPB6pO_aKU8ty0A3PspSBTQyqXg/
• FRR Plans (June 2020): https://mailarchive.ietf.org/arch/msg/lsvr/wCXxSObjSy0Vih5SRS2PPbfacz8/

3. Intellectual Property
During the WGLC IPR calls were performed. No claims for IPR awareness were mentioned by WG members and neither by any of the participating document authors.

4. Other Points
No downward references
Request IANA to assign the BGP-LS/BGP-LS-SPF (AFI 16388 / SAFI TBD1) as described in [RFC4760].
From safi range [1-63] standards action: https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml
When this registry is modified, the YANG module [iana-routing-types] must be updated as defined in [RFC8294].
This draft also defines five attribute TLVs for BGP-LS NLRI from the "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" Registry
Expert review suggested by IANA:
https://www.iana.org/assignments/bgp-ls-parameters/bgp-ls-parameters.xhtml
The draft request IANA to assign types for the
• SPF capability TLV
• Sequence Number TLV
• IPv4 Link Prefix-Length TLV
• IPv6 Link Prefix-Length TLV
• SPF Status TLV.

WG Yang draft in progress found here - https://datatracker.ietf.org/doc/draft-ietf-lsvr-bgp-ls-yang/00/

5. Checklist
• This applicability for bgp-spf (https://www.ietf.org/id/draft-ietf-lsvr-bgp-spf-09.txt) draft is progressed in parallel with 'I-D.ietf-lsvr-applicability'

Notification list changed to Gunter Van de Velde <gunter.van_de_velde@nokia.com>, aretana.ietf@gmail.com, victor@jvknet.com from Gunter Van de Velde <gunter.van_de_velde@nokia.com>, aretana.ietf@gmail.com because the document shepherd was set

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?

Proposed Standard

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

Many Massively Scaled Data Centers (MSDCs) have converged on simplified layer 3 routing.  Furthermore, requirements for operational simplicity have led many of these MSDCs to converge on BGP as their single routing protocol for both their fabric routing and their Data Center Interconnect (DCI) routing.  This draft describes a solution which leverages BGP Link-State distribution and the Shortest Path First (SPF) algorithm like Internal Gateway Protocols (IGPs) such as OSPF.
How is this done?
This document augments BGP-LS [RFC7752] by replacing its use of the existing Decision Process.  Rather than reusing the BGP-LS SAFI, the BGP-LS-SPF SAFI is introduced to insure backward compatibility.  The BGP Phase 1 and 2 decision functions of the Decision Process are replaced with the Shortest Path First (SPF) algorithm also known as the Dijkstra algorithm.  The BGP Phase 3 decision function is also simplified since it is no longer dependent on the previous phases.  This solution avails the benefits of both BGP and SPF-based IGPs.  These include TCP based flow-control, no periodic link-state refresh, and completely incremental NLRI advertisement.  These advantages can reduce the overhead in MSDCs where there is a high degree of Equal Cost Multi-Path (ECMPs) and the topology is very stable.  Additionally, using an SPF-based computation can support fast convergence and the computation of Loop-Free Alternatives (LFAs) [RFC5286] in the event of link failures.  Furthermore, a BGP based solution lends itself to multiple peering models including those incorporating route-reflectors [RFC4456] or controllers.


Working Group Summary:

The LSVR WG enjoyed a turbulent startup period. The IDR WG and LSR WG handle routing for interdomain and intradomain. LSVR is using foundational technology from both BGP and SPF based routing protocols. The IETF face-2-face meetings included IDR and LSR WG participants to voice the depths of their experience and technology authority. This contributed to develop and provide feedback upon the draft draft-ietf-lsvr-bgp-spf.
The draft went through few iterations of volunteer review cycles that have been tracked within the WG email list. In addition, the draft went through early directorate reviews. The OPSDIR review executed upon an early version went well (state: READY), while RTGDIR (state: HAS ISSUES) review caused additional technology discussion resulting in the draft to be updated upon the feedback provided (See: https://mailarchive.ietf.org/arch/msg/lsvr/9z_KGdwqHlmhnzD5HWrarmlSroU/ ).
In addition, the LSVR chairs asked expert reviewers to provide feedback on the document, and those have been included and discussed on the WG mailing list.

The document went through two cycles of WGLC to finally result into current documentation status:

WGLC#1 on draft-ietf-lsvr-bgp-spf-03
Date: 3 December 208 to 17 December 2018
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/-7zKGZ-PIXCNnpmxfEjHVSEUqXc/
WGLC#2 on draft-ietf-lsvr-bgp-spf-05
Date: 23 September 2019 – 7 October 2019
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/A066U6av_6--WDo7BRFswOtMea4/


Document Quality:

Arrcus (March 2019): https://mailarchive.ietf.org/arch/msg/lsvr/OPB6pO_aKU8ty0A3PspSBTQyqXg/
FRR (Plans to support): https://mailarchive.ietf.org/arch/msg/lsvr/wCXxSObjSy0Vih5SRS2PPbfacz8/


Personnel:

Document Shepherd: Gunter Van de Velde
Responsible Area Director: Alvaro Retana

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.

Document went through few iterations of review. This document is ready for publication.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?

Review cycle was contributed by experts, and working implementation exists.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.

No

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.

No specific concerns

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?

Yes, all authors responded on the list about IPR ( there is no IPR awareness.
No other WG member responded with any IPRdisclosure when WGLC was initiated.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.

No

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?

Document went through 2 WGLCs
Document has been presented at each IETF LSVr WG meeting to inform about updates and changes
Feedback has been promptly incorporated by the document authors

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)

No threatening for an appeal on this document

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

When going trough the idnit check 12 missing document references were found.
However, those references for proposed standard are referenced in the informational section of the draft
One informational draft [Missing Reference: 'I-D.ietf-lsvr-applicability'] is progressed in parallel with this draft and describe how to apply the technology in a network environment.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No such components included.
YANG is to progressed in a separate LSVR WG document

(13) Have all references within this document been identified as either normative or informative?

Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?

Yes, the draft [ietf-idr-bgpls-segment-routing-epe]

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.

No

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.

No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).

IANA section document the request of IANA code points
no indications for code-point have been provided

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.

Request IANA to assign the BGP-LS/BGP-LS-SPF (AFI 16388 / SAFI TBD1) as described in [RFC4760].
From safi range [1-63] standards action: https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml
When this registry is modified, the YANG module [iana-routing-types] must be updated as defined in [RFC8294].

This draft also defines five attribute TLVs for BGP-LS NLRI from the "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" Registry
Expert review suggested by IANA:

https://www.iana.org/assignments/bgp-ls-parameters/bgp-ls-parameters.xhtml
The draft request IANA to assign types for the

  * SPF capability TLV
  * Sequence Number TLV
  * IPv4 Link Prefix-Length TLV
  * IPv6 Link Prefix-Length TLV
  * SPF Status TLV.

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.

YANG definition is to be defined in a seperate LSVR WG document.
This work has not been initiated by the LSVR WG.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?

No YANG module included

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?

Proposed Standard

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

Many Massively Scaled Data Centers (MSDCs) have converged on simplified layer 3 routing.  Furthermore, requirements for operational simplicity have led many of these MSDCs to converge on BGP as their single routing protocol for both their fabric routing and their Data Center Interconnect (DCI) routing.  This draft describes a solution which leverages BGP Link-State distribution and the Shortest Path First (SPF) algorithm like Internal Gateway Protocols (IGPs) such as OSPF.
How is this done?
This document augments BGP-LS [RFC7752] by replacing its use of the existing Decision Process.  Rather than reusing the BGP-LS SAFI, the BGP-LS-SPF SAFI is introduced to insure backward compatibility.  The BGP Phase 1 and 2 decision functions of the Decision Process are replaced with the Shortest Path First (SPF) algorithm also known as the Dijkstra algorithm.  The BGP Phase 3 decision function is also simplified since it is no longer dependent on the previous phases.  This solution avails the benefits of both BGP and SPF-based IGPs.  These include TCP based flow-control, no periodic link-state refresh, and completely incremental NLRI advertisement.  These advantages can reduce the overhead in MSDCs where there is a high degree of Equal Cost Multi-Path (ECMPs) and the topology is very stable.  Additionally, using an SPF-based computation can support fast convergence and the computation of Loop-Free Alternatives (LFAs) [RFC5286] in the event of link failures.  Furthermore, a BGP based solution lends itself to multiple peering models including those incorporating route-reflectors [RFC4456] or controllers.


Working Group Summary:

The LSVR WG enjoyed a turbulent startup period. The IDR WG and LSR WG handle routing for interdomain and intradomain. LSVR is using foundational technology from both BGP and SPF based routing protocols. The IETF face-2-face meetings included IDR and LSR WG participants to voice the depths of their experience and technology authority. This contributed to develop and provide feedback upon the draft draft-ietf-lsvr-bgp-spf.
The draft went through few iterations of volunteer review cycles that have been tracked within the WG email list. In addition, the draft went through early directorate reviews. The OPSDIR review executed upon an early version went well (state: READY), while RTGDIR (state: HAS ISSUES) review caused additional technology discussion resulting in the draft to be updated upon the feedback provided (See: https://mailarchive.ietf.org/arch/msg/lsvr/9z_KGdwqHlmhnzD5HWrarmlSroU/ ).
In addition, the LSVR chairs asked expert reviewers to provide feedback on the document, and those have been included and discussed on the WG mailing list.

The document went through two cycles of WGLC to finally result into current documentation status:

WGLC#1 on draft-ietf-lsvr-bgp-spf-03
Date: 3 December 208 to 17 December 2018
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/-7zKGZ-PIXCNnpmxfEjHVSEUqXc/
WGLC#2 on draft-ietf-lsvr-bgp-spf-05
Date: 23 September 2019 – 7 October 2019
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/A066U6av_6--WDo7BRFswOtMea4/


Document Quality:

Arrcus (March 2019): https://mailarchive.ietf.org/arch/msg/lsvr/OPB6pO_aKU8ty0A3PspSBTQyqXg/
FRR (Plans to support): https://mailarchive.ietf.org/arch/msg/lsvr/wCXxSObjSy0Vih5SRS2PPbfacz8/


Personnel:

Document Shepherd: Gunter Van de Velde
Responsible Area Director: Alvaro Retana

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.

Document went through few iterations of review. This document is ready for publication.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?

Review cycle was contributed by experts, and working implementation exists.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.

No

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.

No specific concerns

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?

Yes, all authors responded on the list about IPR ( there is no IPR awareness.
No other WG member responded with any IPRdisclosure when WGLC was initiated.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.

No

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?

Document went through 2 WGLCs
Document has been presented at each IETF LSVr WG meeting to inform about updates and changes
Feedback has been promptly incorporated by the document authors

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)

No threatening for an appeal on this document

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

When going trough the idnit check 12 missing document references were found.
However, those references for proposed standard are referenced in the informational section of the draft
One informational draft [Missing Reference: 'I-D.ietf-lsvr-applicability'] is progressed in parallel with this draft and describe how to apply the technology in a network environment.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

No such components included.
YANG is to progressed in a separate LSVR WG document

(13) Have all references within this document been identified as either normative or informative?

Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?

Yes, the draft [ietf-idr-bgpls-segment-routing-epe]

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.

No

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.

No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).

IANA section document the request of IANA code points
no indications for code-point have been provided

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.

Request IANA to assign the BGP-LS/BGP-LS-SPF (AFI 16388 / SAFI TBD1) as described in [RFC4760].
From safi range [1-63] standards action: https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml
When this registry is modified, the YANG module [iana-routing-types] must be updated as defined in [RFC8294].

This draft also defines five attribute TLVs for BGP-LS NLRI from the "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" Registry
Expert review suggested by IANA:

https://www.iana.org/assignments/bgp-ls-parameters/bgp-ls-parameters.xhtml
The draft request IANA to assign types for the

  * SPF capability TLV
  * Sequence Number TLV
  * IPv4 Link Prefix-Length TLV
  * IPv6 Link Prefix-Length TLV
  * SPF Status TLV.

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.

YANG definition is to be defined in a seperate LSVR WG document.
This work has not been initiated by the LSVR WG.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?

No YANG module included

Waiting for all authors/contributors to comment on IPR awareness
Waiting for confirmation that document addressed all routing directorate issues identified
Waiting for authors to confirm that comments during WGLC have been sufficiently addressed in the draft