RFC 6232
Purge Originator Identification TLV for IS-IS
RFC 6232: Purge Originator Identification TLV for IS-IS 💖
okay bestie, RFC 6232 is a Standards Track doc from May 2011 🎀 Its ISSN is 2070-1721. The authors are F. Wei, Y. Qin, and Z. Li from China Mobile, T. Li from Cisco Systems, Inc., and J. Dong from Huawei Technologies 🌸 It updates RFC 5301, RFC 5304, and RFC 5310, so it's basically adding to those specs and not replacing them ✨
Abstract ✨
okay so right now, an IS-IS purge doesn't carry any info about which Intermediate System (IS) made it 😭 that makes it sooo hard to track down where it came from 🙈
the fix is a new TLV that gets added to purges and stores the system ID of the IS that generated it. normal LSP flooding doesn't change LSP contents, so this TLV should ride along with the purge as it spreads 🦋
this doc updates RFC 5301, RFC 5304, and RFC 5310 💜
Status of This Memo ✨
this is an Internet Standards Track document 🔥
it's a product of the Internet Engineering Task Force (IETF) 👑 it represents the consensus of the IETF community, got public review, and was approved for publication by the Internet Engineering Steering Group (IESG) 💅 for more on Internet Standards, check Section 2 of RFC 5741 🌈
for the current status, any errata, and how to send feedback, go to http://www.rfc-editor.org/info/rfc6232 🫶
Copyright Notice ✨
Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. 💜
this doc is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) as they stood on the publication date 🍓 please actually read those, because they spell out your rights and restrictions for this doc 🙈 any Code Components pulled from this doc must 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 ⭐
Table of Contents 🧚
1. Introduction ....................................................2
2. Requirements Language ...........................................3
3. The Purge Originator Identification (POI) TLV ...................3
4. Using the Dynamic Hostname TLV in Purges ........................3
5. Security Considerations .........................................4
6. IANA Considerations .............................................4
7. Acknowledgments .................................................4
8. Normative References ............................................41. Introduction ✨
IS-IS [ISO-10589] is a routing protocol that's super popular in big IP networks 🌈 it's got strong scalability and fast convergence, so no wonder people love it 💖
IS-IS floods purges across an entire area, no matter which IS started the purge 😭 if a network operator wants to figure out why a purge happened, it's really hard to find out where it came from. right now IS-IS has no way to track down who originated a purge 🙈 this doc fixes that by adding a TLV to purges that records the system ID of the IS that generated it ✨
field experience has shown a few situations where an IS can wrongly generate a purge 💀 all of them come from implementation problems, or from implementations that predate [ISO-TC1] and create a purge when they get a corrupted Link State Protocol Data Unit (LSP) 😭
2. 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 [RFC2119] 💅
3. The Purge Originator Identification (POI) TLV 🦋
this doc defines a TLV that goes inside purges 🌸 if an IS generates a purge, it SHOULD include this TLV in the purge with its own system ID 💖 if an IS receives a purge that doesn't have this TLV, it SHOULD add this TLV with both its own system ID and the system ID of the IS it got the purge from ✨ that way, ISs that receive purges can log the system ID of the originator, or the upstream source of the purge 👑 it makes life way easier for the network admin to track down where the purge started and what caused it 🫶 this is also handy for developers working in lab setups 🧚
the POI TLV is defined like this:
CODE - 13
LENGTH - total length of the value field.
VALUE -
Number of system IDs carried in this TLV (1 octet) -- only the
values 1 and 2 are defined.
System ID of the Intermediate System that inserted this TLV.
System ID of the Intermediate System from which the purge was
received (optional).the POI TLV SHOULD be found in all purges and MUST NOT be found in LSPs with a non-zero Remaining Lifetime 🔥 (no sneaking it into regular LSPs, bestie 🙅♀️)
4. Using the Dynamic Hostname TLV in Purges 🌈
this doc also expands how the Dynamic hostname TLV (type 137) [RFC5301] gets used, so it's even faster to figure out which system made the purge ⭐ this TLV MAY be included in purges 💜 implementations SHOULD include one instance of the Dynamic hostname TLV if the POI TLV is included 🍓 only the local hostname should be inserted 🎀
5. Security Considerations 💀
ok this section is serious, bestie 😭 using these extensions with authentication as defined in [RFC5304] or [RFC5310] will cause legacy systems that strictly follow either of those RFCs to discard purges 💀 that can mess up the correctness and consistency of the routing database unless every IS in the network supports these extensions 🙈 so, all implementations in a domain that use authentication MUST be upgraded to receive the POI TLV before any IS is allowed to generate a purge with the POI TLV 🚨
heads up: skipping that upgrade order can break routing consistency across the whole domain. don't skip it!
there's more on how the POI TLV, the Dynamic hostname TLV, and the Authentication TLV interact in [RFC6233] 🫶
6. IANA Considerations 🌸
IANA has assigned code point 13 for the 'Purge Originator Identification' TLV from the IS-IS 'TLV Codepoints' registry ✨ the additional values for this TLV should be IIH:n, LSP:y, SNP:n, and Purge:y 💖
7. Acknowledgments 💜
huge thanks to Adrian Farrel and Daniel King for their comments that made this doc better and got it moving 🙌
the first version was mainly written by Lianyuan Li 🧚
thanks to everyone who discussed this on the mailing list too 💅 some improvements in this doc came straight from those conversations 🦋
8. Normative References 🌈
[ISO-10589] ISO, "Intermediate system to Intermediate system
intra-domain routeing information exchange protocol for
use in conjunction with the protocol for providing the
connectionless-mode Network Service (ISO 8473)",
ISO/IEC 10589:2002.
[ISO-TC1] ISO, "Intermediate system to Intermediate system
intra-domain routeing information exchange protocol for
use in conjunction with the protocol for providing the
connectionless-mode Network Service (ISO 8473) --
Technical Corrigendum 1", ISO/IEC 10589:1992/
Cor.1:1993.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5301] McPherson, D. and N. Shen, "Dynamic Hostname Exchange
Mechanism for IS-IS", RFC 5301, October 2008.
[RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic
Authentication", RFC 5304, October 2008.
[RFC5310] Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R.,
and M. Fanto, "IS-IS Generic Cryptographic
Authentication", RFC 5310, February 2009.
[RFC6233] Li, T. and L. Ginsberg, "IS-IS Registry Extension for
Purges", RFC 6233, May 2011.Authors' Addresses 🧚
Fang Wei
China Mobile
No. 29, Financial Street, Xicheng District
Beijing 100032
P.R. China
EMail: weifang@chinamobile.com
Yue Qin
China Mobile
No. 29, Financial Street, Xicheng District
Beijing 100032
P.R. China
EMail: qinyue@chinamobile.com
Zhenqiang Li
China Mobile
Unit2, Dacheng Plaza, No. 28 Xuanwumenxi Ave., Xuanwu District
Beijing 100053
P.R. China
EMail: lizhenqiang@chinamobile.com
Tony Li
Cisco Systems, Inc.
170 W. Tasman Dr.
San Jose, CA 95134
USA
EMail: tony.li@tony.li
Jie Dong
Huawei Technologies
KuiKe Building, No. 9 Xinxi Rd., Haidian District
Beijing 100085
P.R. China
EMail: dongjie_dj@huawei.com📦 where this page comes from
- ietf: rfc6232 2011-05
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms