IPv6 Maintenance J. Iurman Internet-Draft ULiege Intended status: Standards Track 6 August 2022 Expires: 7 February 2023 Carrying a Generic Identifier in IPv6 packets draft-iurman-6man-generic-id-00 Abstract Some recent use cases seem to have a need for carrying IDs within packets. Two examples are _I-D.draft-ietf-6man-enhanced-vpn-vtn-id_ and _I-D.draft-li-6man-topology-id_. While they might perfectly make sense on their own, each document requires IANA to allocate a new code point for a new option, which could quickly exhaust the allocation space if similar designs are proposed in the future. As an example, one might need an 8-bit ID, while another one might need a 24-bit, 32-bit, or 64-bit ID. Or, even worse, one might need a 32-bit ID in a specific context, while someone else might also need a 32-bit ID in another context. Therefore, allocating a new code point for each similar option is probably not the way to go. About This Document This note is to be removed before publishing as an RFC. The latest revision of this draft can be found at https://IurmanJ.github.io/draft-iurman-6man-generic-id/draft-iurman- 6man-generic-id.html. Status information for this document may be found at https://datatracker.ietf.org/doc/draft-iurman-6man-generic- id/. Discussion of this document takes place on the IPv6 Maintenance Working Group mailing list (mailto:ipv6@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/ipv6/. Subscribe at https://www.ietf.org/mailman/listinfo/ipv6/. Source for this draft and an issue tracker can be found at https://github.com/IurmanJ/draft-iurman-6man-generic-id. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Iurman Expires 7 February 2023 [Page 1] Internet-Draft Generic Identifier August 2022 Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 7 February 2023. Copyright Notice Copyright (c) 2022 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3 3. New IPv6 Destination and Hop-by-Hop Options . . . . . . . . . 3 3.1. Generic ID Option . . . . . . . . . . . . . . . . . . . . 3 3.2. Generic Context-ID Option . . . . . . . . . . . . . . . . 4 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 4.1. Context-Type . . . . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 6.1. Normative References . . . . . . . . . . . . . . . . . . 6 6.2. Informative References . . . . . . . . . . . . . . . . . 6 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7 Iurman Expires 7 February 2023 [Page 2] Internet-Draft Generic Identifier August 2022 1. Introduction Some recent use cases seem to have a need for carrying IDs within packets. Two examples are [I-D.draft-ietf-6man-enhanced-vpn-vtn-id] and [I-D.draft-li-6man-topology-id]. While they might perfectly make sense on their own, each document requires IANA to allocate a new code point for a new option, which could quickly exhaust the allocation space if similar designs are proposed in the future. As an example, one might need an 8-bit ID, while another one might need a 24-bit, 32-bit, or 64-bit ID. Or, even worse, one might need a 32-bit ID in a specific context, while someone else might also need a 32-bit ID in another context. Therefore, allocating a new code point for each similar option is probably not the way to go. This document proposes a solution to carry IDs generically to avoid the problem mentioned previously. Two new Hop-by-Hop and Destination options are defined, called "Generic ID Option" and "Generic Context- ID Option". Both are defined and explained in this document. 2. Conventions and Definitions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 3. New IPv6 Destination and Hop-by-Hop Options 3.1. Generic ID Option For simple use cases where an ID is carried without extra fields and without any specific context, a new option type "Generic ID" is defined to carry such ID generically in IPv6 packets, as defined below: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Type | Opt Data Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Generic ID (variable length) ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1. Generic ID Option Iurman Expires 7 February 2023 [Page 3] Internet-Draft Generic Identifier August 2022 where: * Option Type: 8-bit option type identifier as defined in Section 4. * Opt Data Len: 8-bit unsigned integer. Length of the Generic ID field, in octets. * Generic ID: variable length field. Note: as an example, both [I-D.draft-ietf-6man-enhanced-vpn-vtn-id-00] and [I-D.draft-li-6man-topology-id] should use this option to carry IDs they define respectively. 3.2. Generic Context-ID Option For other use cases where an ID is carried with extra fields or when a context is required, a new option type "Generic Context-ID" is defined to carry such ID generically in IPv6 packets, as defined below: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Type | Opt Data Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Context-Type | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Context Data (variable length) ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2. Generic Context-ID Option where: * Option Type: 8-bit option type identifier as defined in Section 4. * Opt Data Len: 8-bit unsigned integer. Length of this option, in octets, not including the first 2 octets. * Context-Type: 16-bit field as defined in Section 4.1. * Reserved: 16-bit field MUST be set to zero upon transmission and ignored upon reception. * Context Data: variable length field. Context-Type-specific data. Iurman Expires 7 February 2023 [Page 4] Internet-Draft Generic Identifier August 2022 Note: as an example, [I-D.draft-ietf-6man-enhanced-vpn-vtn-id] should use this option to carry the 16-bit ID and flags it defines. 4. IANA Considerations This document requests the following IPv6 Option Type assignments from the Destination Options and Hop-by-Hop Options sub-registry of Internet Protocol Version 6 (IPv6) Parameters. http://www.iana.org/assignments/ipv6-parameters/ ipv6-parameters.xhtml#ipv6-parameters-2 Binary Value Description Reference act chg rest -------------------------------------------------------------- 00 0 TBD Generic ID Option [This document] 00 0 TBD Generic Context-ID Option [This document] This document also requests IANA to define a registry group named "Generic Context-ID". This group includes the following registries: * Context-Type The subsequent subsections detail the registries therein contained. 4.1. Context-Type This registry defines 65535 code points for the Context-Type field to identify the type of context. The following code points are defined in this document: * 0: Reserved * 1: VTN [I-D.draft-ietf-6man-enhanced-vpn-vtn-id] Other code points are available for assignment via the "IETF Review" process, as per [RFC8126]. New registration requests MUST use the following template: * Name: name of the newly registered Context-Type. * Code point: desired value of the requested code point. * Reference: reference to the document that defines the new Context- Type. Iurman Expires 7 February 2023 [Page 5] Internet-Draft Generic Identifier August 2022 5. Security Considerations As this document describes new options for IPv6, these are similar to the security considerations of [RFC8200] and the weakness documented in [RFC8250]. This document does not define the data contents of custom Generic Context-ID options. These custom options will have security considerations corresponding to their defined data contents that need to be described where those formats are defined. 6. References 6.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 6.2. Informative References [I-D.draft-ietf-6man-enhanced-vpn-vtn-id] Dong, J., Li, Z., Xie, C., Ma, C., and G. Mishra, "Carrying Virtual Transport Network (VTN) Information in IPv6 Extension Header", Work in Progress, Internet-Draft, draft-ietf-6man-enhanced-vpn-vtn-id-01, 11 July 2022, . [I-D.draft-ietf-6man-enhanced-vpn-vtn-id-00] Dong, J., Li, Z., Xie, C., Ma, C., and G. S. Mishra, "Carrying Virtual Transport Network (VTN) Identifier in IPv6 Extension Header", Work in Progress, Internet-Draft, draft-ietf-6man-enhanced-vpn-vtn-id-00, 5 March 2022, . [I-D.draft-li-6man-topology-id] Li, Z., Hu, Z., and J. Dong, "Topology Identifier in IPv6 Extension Header", Work in Progress, Internet-Draft, draft-li-6man-topology-id-00, 20 March 2022, . Iurman Expires 7 February 2023 [Page 6] Internet-Draft Generic Identifier August 2022 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, July 2017, . [RFC8250] Elkins, N., Hamilton, R., and M. Ackermann, "IPv6 Performance and Diagnostic Metrics (PDM) Destination Option", RFC 8250, DOI 10.17487/RFC8250, September 2017, . Acknowledgments Author's Address Justin Iurman ULiege Institut Montefiore B28 Allée de la Découverte 10 4000 Liège Belgium Email: justin.iurman@uliege.be Iurman Expires 7 February 2023 [Page 7]