--- 1/draft-ietf-lsr-isis-srv6-extensions-13.txt 2021-04-22 05:13:47.423036399 -0700 +++ 2/draft-ietf-lsr-isis-srv6-extensions-14.txt 2021-04-22 05:13:47.475037694 -0700 @@ -1,24 +1,24 @@ Networking Working Group P. Psenak, Ed. Internet-Draft C. Filsfils Updates: 7370 (if approved) Cisco Systems Intended status: Standards Track A. Bashandy -Expires: October 14, 2021 Individual +Expires: October 24, 2021 Individual B. Decraene Orange Z. Hu Huawei Technologies - April 12, 2021 + April 22, 2021 IS-IS Extension to Support Segment Routing over IPv6 Dataplane - draft-ietf-lsr-isis-srv6-extensions-13 + draft-ietf-lsr-isis-srv6-extensions-14 Abstract The Segment Routing (SR) allows for a flexible definition of end-to- end paths by encoding paths as sequences of topological sub-paths, called "segments". Segment routing architecture can be implemented over an MPLS data plane as well as an IPv6 data plane. This document describes the IS-IS extensions required to support Segment Routing over an IPv6 data plane. @@ -39,72 +39,77 @@ 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 October 14, 2021. + This Internet-Draft will expire on October 24, 2021. Copyright Notice Copyright (c) 2021 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 . . . . . . . . . . . . . . . . . . . . . . . . 3 - 2. SRv6 Capabilities sub-TLV . . . . . . . . . . . . . . . . . . 3 + 2. SRv6 Capabilities sub-TLV . . . . . . . . . . . . . . . . . . 4 3. Advertising Supported Algorithms . . . . . . . . . . . . . . 4 4. Advertising Maximum SRv6 SID Depths . . . . . . . . . . . . . 4 4.1. Maximum Segments Left MSD Type . . . . . . . . . . . . . 5 4.2. Maximum End Pop MSD Type . . . . . . . . . . . . . . . . 5 4.3. Maximum H.Encaps MSD Type . . . . . . . . . . . . . . . . 5 - 4.4. Maximum End D MSD Type . . . . . . . . . . . . . . . . . 5 + 4.4. Maximum End D MSD Type . . . . . . . . . . . . . . . . . 6 5. SRv6 SIDs and Reachability . . . . . . . . . . . . . . . . . 6 6. Advertising Anycast Property . . . . . . . . . . . . . . . . 7 7. Advertising Locators and End SIDs . . . . . . . . . . . . . . 8 - 7.1. SRv6 Locator TLV Format . . . . . . . . . . . . . . . . . 8 + 7.1. SRv6 Locator TLV Format . . . . . . . . . . . . . . . . . 9 7.2. SRv6 End SID sub-TLV . . . . . . . . . . . . . . . . . . 10 8. Advertising SRv6 Adjacency SIDs . . . . . . . . . . . . . . . 12 8.1. SRv6 End.X SID sub-TLV . . . . . . . . . . . . . . . . . 12 8.2. SRv6 LAN End.X SID sub-TLV . . . . . . . . . . . . . . . 14 9. SRv6 SID Structure Sub-Sub-TLV . . . . . . . . . . . . . . . 16 10. Advertising Endpoint Behaviors . . . . . . . . . . . . . . . 17 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 11.1. SRv6 Locator TLV . . . . . . . . . . . . . . . . . . . . 17 11.1.1. SRv6 End SID sub-TLV . . . . . . . . . . . . . . . . 18 11.1.2. Revised sub-TLV table . . . . . . . . . . . . . . . 18 11.2. SRv6 Capabilities sub-TLV . . . . . . . . . . . . . . . 19 11.3. SRv6 End.X SID and SRv6 LAN End.X SID sub-TLVs . . . . . 19 11.4. MSD Types . . . . . . . . . . . . . . . . . . . . . . . 20 11.5. Sub-Sub-TLVs for SID Sub-TLVs . . . . . . . . . . . . . 20 11.6. Prefix Attribute Flags Sub-TLV . . . . . . . . . . . . . 21 - 12. Security Considerations . . . . . . . . . . . . . . . . . . . 21 - 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 21 - 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 - 14.1. Normative References . . . . . . . . . . . . . . . . . . 22 - 14.2. Informative References . . . . . . . . . . . . . . . . . 25 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 + 11.7. ISIS SRv6 Capabilities sub-TLV Flags Registry . . . . . 21 + 11.8. ISIS SRv6 Locator TLV Flags Registry . . . . . . . . . . 21 + 11.9. ISIS SRv6 End SID sub-TLV Flags Registry . . . . . . . . 22 + 11.10. ISIS SRv6 End.X SID and LAN End.X SID sub-TLVs Flags + Registry . . . . . . . . . . . . . . . . . . . . . . . . 22 + 12. Security Considerations . . . . . . . . . . . . . . . . . . . 23 + 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 23 + 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 24 + 14.1. Normative References . . . . . . . . . . . . . . . . . . 24 + 14.2. Informative References . . . . . . . . . . . . . . . . . 27 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27 1. Introduction With Segment Routing (SR) [RFC8402], a node steers a packet through an ordered list of instructions, called segments. Segments are identified through Segment Identifiers (SIDs). Segment Routing can be directly instantiated on the IPv6 data plane through the use of the Segment Routing Header defined in [RFC8754]. @@ -409,29 +414,28 @@ Flags: 1 octet. The following flags are defined 0 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |D| Reserved | +-+-+-+-+-+-+-+-+ where: - D bit: Same as described in section 4.1. of [RFC5305]. + D-flag: Same as described in section 4.1. of [RFC5305]. The remaining bits are reserved for future use. They MUST be set to zero on transmission and MUST be ignored on receipt. Algorithm: 1 octet. As defined in [RFC8665]. Loc-Size: 1 octet. Number of bits in the SRv6 Locator field. - MUST be from the range (1 - 128). The TLV MUST be ignored if the Loc-Size is outside of this range. Locator: 1-16 octets. This field encodes the advertised SRv6 Locator. The Locator is encoded in the minimal number of octets for the given number of bits. Trailing bits MUST be set to zero and ignored when received. Sub-TLV-length: 1 octet. Number of octets used by sub-TLVs @@ -896,20 +900,93 @@ This document adds a new bit in the "Bit Values for Prefix Attribute Flags Sub-TLV" registry: Bit #: 4 Description: Anycast Flag (A-flag) Reference: This document (Section 6). +11.7. ISIS SRv6 Capabilities sub-TLV Flags Registry + + This document requests a new IANA registry be created under the IS-IS + TLV Codepoints Registry to control the assignment of bits in the + Flags field of the ISIS SRv6 Capabilities sub-TLV specified in this + document (Section 2). The suggested name of the new registry is + "ISIS SRv6 Capabilities sub-TLV Flags". The registration procedure + is "Expert Review" as defined in [RFC8126]. Guidance for the + Designated Experts is provided in [RFC7370]. The following + assignments are made by this document: + + Bit #: 1 + + Description: O-flag + + Reference: This document (Section 2). + +11.8. ISIS SRv6 Locator TLV Flags Registry + + This document requests a new IANA registry be created under the IS-IS + TLV Codepoints Registry to control the assignment of bits in the + Flags field of the ISIS SRv6 SRv6 Locator TLV specified in this + document (Section 7.1). The suggested name of the new registry is + "ISIS SRv6 Locator TLV Flags". The registration procedure is "Expert + Review" as defined in [RFC8126]. Guidance for the Designated Experts + is provided in [RFC7370]. The following assignments are made by this + document: + + Bit #: 0 + + Description: D-flag + + Reference: This document (Section 7.1). + +11.9. ISIS SRv6 End SID sub-TLV Flags Registry + + This document requests a new IANA registry be created under the IS-IS + TLV Codepoints Registry to control the assignment of bits in the + Flags field of the ISIS SRv6 End SID sub-TLV specified in this + document (Section 7.2). The suggested name of the new registry is + "ISIS SRv6 End SID sub-TLV Flags". The registration procedure is + "Expert Review" as defined in [RFC8126]. Guidance for the Designated + Experts is provided in [RFC7370]. No assignments are made by this + document. + +11.10. ISIS SRv6 End.X SID and LAN End.X SID sub-TLVs Flags Registry + + This document requests a new IANA registry be created under the IS-IS + TLV Codepoints Registry to control the assignment of bits in the + Flags field of the ISIS SRv6 End.X SID and LAN End.X SID sub-TLVs + (Section 8.1 and Section 8.2). The suggested name of the new + registry is "ISIS SRv6 End.X SID and LAN End.X SID sub-TLVs Flags". + The registration procedure is "Expert Review" as defined in + [RFC8126]. Guidance for the Designated Experts is provided in + [RFC7370]. The following assignments are made by this document: + + Bit #: 0 + + Description: B-flag + + Reference: This document (Section 8.1). + + Bit #: 1 + + Description: S-flag + + Reference: This document (Section 8.1). + + Bit #: 2 + + Description: P-flag + Reference: This document (Section 8.1). + 12. Security Considerations Security concerns for IS-IS are addressed in [ISO10589], [RFC5304], and [RFC5310]. While IS-IS is deployed under a single administrative domain, there can be deployments where potential attackers have access to one or more networks in the IS-IS routing domain. In these deployments, the stronger authentication mechanisms defined in the aforementioned documents SHOULD be used. This document describes the IS-IS extensions required to support