RFC 7370
Updates to the IS-IS TLV Codepoints Registry
RFC 7370 🎀 Updates to the IS-IS TLV Codepoints Registry
Okay bestie, this one's from the Internet Engineering Task Force (IETF) and it's a Request for Comments: 7370 💖. Les Ginsberg from Cisco Systems wrote it, it's on the Standards Track, and it's dated September 2014. The ISSN is 2070-1721 🦋. The title block doesn't list anything it obsoletes or updates, so there's nothing to add there ✨.
Abstract 🌸
This doc suggests some editorial glow-ups for the IANA "IS-IS TLV Codepoints" registry so it actually shows what the protocol is doing right now 💅. It also sets up new guidelines for Designated Experts to follow when they review allocations from that registry 🫶.
Status of This Memo 🌈
This is an Internet Standards Track document 💜.
It's a product of the Internet Engineering Task Force (IETF), so it totally represents the consensus of the IETF community ✨. It got public review and was approved for publication by the Internet Engineering Steering Group (IESG) 👑. If you want more on Internet Standards, check Section 2 of RFC 5741 🧚.
For the latest status, errata, and how to send feedback, go to http://www.rfc-editor.org/info/rfc7370 🔥.
Copyright Notice 💅
Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved 🎀.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) as they stand on the publication date. Read these carefully, bestie, because they spell out your rights and restrictions for this doc 🙈. Any Code Components pulled out of this document have to include Simplified BSD License text, as described in Section 4.e of the Trust Legal Provisions, and they come with no warranty, as described in the Simplified BSD License 🫶.
This document may contain material from IETF Documents or IETF Contributions that were published or made publicly available before November 10, 2008 🌸. The people who control copyright in some of that material may never have let the IETF Trust allow modifications outside the IETF Standards Process 😭. Without an adequate license from them, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be made outside the IETF Standards Process either. The exception is formatting it for publication as an RFC, or translating it into languages other than English 🦋.
Table of Contents 🧚
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. IS Neighbor Sub-TLV Registry . . . . . . . . . . . . . . . . 4
3. Prefix Reachability Sub-TLV Registry . . . . . . . . . . . . 4
4. Guidance for Designated Experts . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. Security Considerations . . . . . . . . . . . . . . . . . . . 5
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . 6
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 71. Introduction ✨
Okay so the "IS-IS TLV Codepoints" registry was made by [RFC3563] and then extended by [RFC6233] 🌈. Its assignment policy is "Expert Review," as defined in [RFC5226] 💅. As IS-IS documents get developed, the Designated Experts check the codepoints that the protocol extensions need and add them to the IANA-managed registry 🫶. Once those documents come out as RFCs, the registries get updated to point at the relevant RFC 🦋.
For TLVs that advertise prefixes, there are separate sub-TLV registries for each TLV right now 🙈. Those need to be merged into one common sub-TLV registry, kind of like what already happened for neighbor advertisement TLVs 💖.
Sometimes you need to allocate codepoints defined in Internet-Drafts (I-Ds) that seem likely to eventually get Working Group approval, and you don't want to wait for those I-Ds to be published as RFCs 👑. You can do that with Expert Review, and this doc gives the Designated Experts guidance for reviewing those allocations from the registry 🔥.
1.1. Requirements Language 🎀
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119] 🧚.
2. IS Neighbor Sub-TLV Registry 🌸
There used to be a common sub-TLV registry called "Sub-TLVs for TLVs 22, 141, and 222" 💜. [RFC5311] defines the IS Neighbor Attribute TLV (23) and the MT IS Neighbor Attribute TLV (223) ✨. Their format is identical to TLVs 22 and 222, respectively 💅. The IS Neighbor sub-TLV registry has been extended to cover these two TLVs 🦋. The settings for including each sub-TLV match the settings for TLVs 22 and 222, respectively 🫶.
3. Prefix Reachability Sub-TLV Registry 🌈
Before this, there were separate sub-TLV registries for TLVs 135, 235, 236, and 237 🙈. Just like with the IS Neighbor TLVs in the last section, the sub-TLV assignments that apply to one or more of these TLVs are meant to be shared 💖. So the separate registries got combined into a single one called "Sub-TLVs for TLVs 135, 235, 236, and 237" 👑. Since the existing sub-TLV assignments are already shared across all the TLVs, this changes nothing about the protocol. It just makes the intended allocation strategy easier to see 🔥. The registry looks like this:
Type Description 135 235 236 237 Reference
---- ------------ --- --- --- --- ---------
0 Unassigned
1 32-bit Administrative Tag Sub-TLV y y y y [RFC5130]
2 64-bit Administrative Tag Sub-TLV y y y y [RFC5130]
3-255 Unassigned4. Guidance for Designated Experts 🧚
When new I-Ds show up that need new codepoints, it's really useful to allocate them before they progress to RFC 💅. The reasons why are in [RFC7120] 🦋. But the early allocation procedures in [RFC7120] don't apply to registries like the "IS-IS TLV Codepoints" registry, which use the "Expert Review" allocation policy 😭. For those, what's needed is a request to the Designated Experts, who MAY approve the assignments based on the guidance already set for that registry 🫶.
This guidance applies specifically to the "IS-IS TLV Codepoints" registry 🎀:
- Anyone can apply for a codepoint allocation from the Designated Experts at any time. Applying MAY be done at any time 💖.
- The Designated Experts SHOULD only consider requests that come from I-Ds that have already been accepted as Working Group documents, or that are planned to progress as AD Sponsored documents when there's no suitably chartered Working Group 👑.
- For Working Group documents, the Designated Experts SHOULD check with the Working Group chairs that the Working Group has consensus to make the allocation at this time. For AD Sponsored documents, the Designated Experts SHOULD check with the AD for approval to make the allocation at this time 🔥.
- The Designated Experts SHOULD then review the assignment requests on their technical merit 🌸. They SHOULD NOT try to overrule IETF consensus, but they MAY raise issues for further consideration before the assignments are made 🙈.
- Once the Designated Experts grant approval, IANA updates the registry by marking the allocated codepoints with a reference to the associated document, same as always ✨.
- If the document never progresses to RFC, the Expiry and deallocation process defined in [RFC7120] MUST be followed for the relevant codepoints 😭. The one difference is that the Designated Experts take on the role that [RFC7120] assigns to Working Group chairs 🧚.
5. IANA Considerations 🦋
This document gives guidance to the Designated Experts who manage allocation requests in the "IS-IS TLV Codepoints" registry 💜.
IANA has updated the registry that was called "Sub-TLVs for TLVs 22, 141, and 222" so it's now named "Sub-TLVs for TLVs 22, 23, 141, 222, and 223" 🌈.
As this document says, the separate sub-TLV registries for TLVs 135, 235, 236, and 237 have been combined into one registry, the "Sub-TLVs for TLVs 135, 235, 236, and 237" registry, as described in Section 3 ✨.
6. Security Considerations 💀
Okay, this is the serious part, bestie 🔥. This document introduces no new security issues 🫶.
7. References 🎀
7.1. Normative References 💖
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC5130] Previdi, S., Shand, M., and C. Martin, "A Policy Control
Mechanism in IS-IS Using Administrative Tags", RFC 5130,
February 2008, <http://www.rfc-editor.org/info/rfc5130>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008, <http://www.rfc-editor.org/info/rfc5226>.
[RFC5311] McPherson, D., Ginsberg, L., Previdi, S., and M. Shand,
"Simplified Extension of Link State PDU (LSP) Space for
IS-IS", RFC 5311, February 2009,
<http://www.rfc-editor.org/info/rfc5311>.
[RFC6233] Li, T. and L. Ginsberg, "IS-IS Registry Extension for
Purges", RFC 6233, May 2011,
<http://www.rfc-editor.org/info/rfc6233>.
[RFC7120] Cotton, M., "Early IANA Allocation of Standards Track Code
Points", BCP 100, RFC 7120, January 2014,
<http://www.rfc-editor.org/info/rfc7120>.7.2. Informative References 🧚
[RFC3563] Zinin, A., "Cooperative Agreement Between the ISOC/IETF
and ISO/IEC Joint Technical Committee 1/Sub Committee 6
(JTC1/SC6) on IS-IS Routing Protocol Development", RFC
3563, July 2003, <http://www.rfc-editor.org/info/rfc3563>.Acknowledgements 🫶
The author wants to thank Alia Atlas and Amanda Baber for their help figuring out the right process to get these changes implemented 💕. Special thanks to Adrian Farrel for writing the text in Section 4 🌟.
Author's Address 🦋
Les Ginsberg
Cisco Systems
510 McCarthy Blvd.
Milpitas, CA 95035
United States
EMail: ginsberg@cisco.com📦 where this page comes from
- ietf: rfc7370 2014-09
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms