Internet Engineering Task Force J. Hui Internet-Draft Google LLC Intended status: Standards Track 19 March 2024 Expires: 20 September 2024 Stub Router Flag in ICMPv6 Router Advertisement Messages draft-hui-6man-stub-router-ra-flag-00 Abstract This document defines a new flag, the Stub Router flag, in the Router Advertisement message that can be used to distinguish configuration information sent by stub routers from information sent by infrastructure routers. This flag is used only by stub routers and is ignored by all other devices. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. 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/. 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Hui Expires 20 September 2024 [Page 1] Internet-Draft Stub Router RA Flag March 2024 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Stub Router Flag . . . . . . . . . . . . . . . . . . . . . . 2 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 2 5. Security Considerations . . . . . . . . . . . . . . . . . . . 3 6. Normative References . . . . . . . . . . . . . . . . . . . . 3 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction A stub router is an autonomously-configuring router that provides IP connectivity between one or more stub networks and one or more infrastructure networks. A common stub router example is a device that attaches a 6LoWPAN-based network to a home network, automatically providing IPv6 forwarding between the two networks without explicit operator configuration. Stub routers are described in [I-D.ietf-snac-simple]. This document defines a new RA flag, the "stub router" flag, which stub routers use to identify RAs sent by other stub routers. 2. Terminology 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. Stub Router Flag The "Stub Router" flag is router advertisement flag bit TBD. The stub router flag is to be used by stub routers. The use of this flag is documented in [I-D.ietf-snac-simple]. Devices that do not implement [I-D.ietf-snac-simple] MUST NOT set the stub router flag, and MUST silently ignore the stub router flag. This means that the presence or absence of the flag should not change the behavior of such devices in any way (other than that it is of course permissible to log and cache the value of the flag as part of normal router advertisement processing, where applicable. 4. IANA Considerations IANA is requested to allocate a flag from the "IPv6 ND Router Advertisement flags" registry of [RFC5175], as specified below: Hui Expires 20 September 2024 [Page 2] Internet-Draft Stub Router RA Flag March 2024 +---------------+----------------------+---------------+ | RA Option Bit | Description | Reference | +---------------+----------------------+---------------+ | TBD | S - Stub Router Flag | This Document | +---------------+----------------------+---------------+ Table 1 5. Security Considerations This protocol shares the security issues of NDP that are documented in the "Security Considerations" section of [RFC4861]. 6. Normative References [I-D.ietf-snac-simple] Lemon, T. and J. Hui, "Automatically Connecting Stub Networks to Unmanaged Infrastructure", Work in Progress, Internet-Draft, draft-ietf-snac-simple-04, 4 March 2024, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, DOI 10.17487/RFC4861, September 2007, . [RFC5175] Haberman, B., Ed. and R. Hinden, "IPv6 Router Advertisement Flags Option", RFC 5175, DOI 10.17487/RFC5175, March 2008, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Author's Address Jonathan Hui Google LLC 1600 Amphitheatre Parkway Mountain View, California 940432 United States of America Hui Expires 20 September 2024 [Page 3] Internet-Draft Stub Router RA Flag March 2024 Email: jonhui@google.com Hui Expires 20 September 2024 [Page 4]