IS-IS Application-Specific Link Attributes
RFC 8919
Document | Type |
RFC - Proposed Standard
(October 2020; No errata)
Was draft-ietf-isis-te-app (lsr WG)
|
|
---|---|---|---|
Authors | Les Ginsberg , Peter Psenak , Stefano Previdi , Wim Henderickx , John Drake | ||
Last updated | 2020-10-22 | ||
Replaces | draft-ginsberg-isis-te-app | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html xml pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Acee Lindem | ||
Shepherd write-up | Show (last changed 2020-01-10) | ||
IESG | IESG state | RFC 8919 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Alvaro Retana | ||
Send notices to | Acee Lindem <acee@cisco.com>, aretana.ietf@gmail.com | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | RFC-Ed-Ack |
Internet Engineering Task Force (IETF) L. Ginsberg Request for Comments: 8919 P. Psenak Category: Standards Track Cisco Systems ISSN: 2070-1721 S. Previdi Huawei Technologies W. Henderickx Nokia J. Drake Juniper Networks October 2020 IS-IS Application-Specific Link Attributes Abstract Existing traffic-engineering-related link attribute advertisements have been defined and are used in RSVP-TE deployments. Since the original RSVP-TE use case was defined, additional applications (e.g., Segment Routing Policy and Loop-Free Alternates) that also make use of the link attribute advertisements have been defined. In cases where multiple applications wish to make use of these link attributes, the current advertisements do not support application- specific values for a given attribute, nor do they support indication of which applications are using the advertised value for a given link. This document introduces new link attribute advertisements that address both of these shortcomings. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8919. Copyright Notice Copyright (c) 2020 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 (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction 1.1. Requirements Language 2. Requirements Discussion 3. Legacy Advertisements 3.1. Legacy Sub-TLVs 3.2. Legacy SRLG Advertisements 4. Advertising Application-Specific Link Attributes 4.1. Application Identifier Bit Mask 4.2. Application-Specific Link Attributes Sub-TLV 4.2.1. Special Considerations for Maximum Link Bandwidth 4.2.2. Special Considerations for Reservable/Unreserved Bandwidth 4.2.3. Considerations for Extended TE Metrics 4.3. Application-Specific SRLG TLV 5. Attribute Advertisements and Enablement 6. Deployment Considerations 6.1. Use of Legacy Advertisements 6.2. Use of Zero-Length Application Identifier Bit Masks 6.3. Interoperability, Backwards Compatibility, and Migration Concerns 6.3.1. Multiple Applications: Common Attributes with RSVP-TE 6.3.2. Multiple Applications: All Attributes Not Shared with RSVP-TE 6.3.3. Interoperability with Legacy Routers 6.3.4. Use of Application-Specific Advertisements for RSVP-TE 7. IANA Considerations 7.1. Application-Specific Link Attributes Sub-TLV 7.2. Application-Specific SRLG TLV 7.3. Sub-sub-TLV Codepoints for Application-Specific Link Attributes Registry 7.4. Link Attribute Application Identifiers Registry 7.5. Sub-TLVs for TLV 238 Registry 8. Security Considerations 9. References 9.1. Normative References 9.2. Informative References Acknowledgements Authors' Addresses 1. Introduction Advertisement of link attributes by the Intermediate System to Intermediate System (IS-IS) protocol in support of traffic engineering (TE) was introduced by [RFC5305] and extended by [RFC5307], [RFC6119], [RFC7308], and [RFC8570]. Use of these extensions has been associated with deployments supporting Traffic Engineering over Multiprotocol Label Switching (MPLS) in the presence of the Resource Reservation Protocol (RSVP), more succinctly referred to as RSVP-TE [RFC3209]. For the purposes of this document, an application is a technologyShow full document text