--- 1/draft-ietf-lsr-isis-srv6-extensions-06.txt 2020-03-23 08:13:47.760696256 -0700 +++ 2/draft-ietf-lsr-isis-srv6-extensions-07.txt 2020-03-23 08:13:47.808697483 -0700 @@ -1,24 +1,24 @@ Networking Working Group P. Psenak, Ed. Internet-Draft C. Filsfils Intended status: Standards Track Cisco Systems -Expires: September 4, 2020 A. Bashandy +Expires: September 24, 2020 A. Bashandy Individual B. Decraene Orange Z. Hu Huawei Technologies - March 3, 2020 + March 23, 2020 IS-IS Extension to Support Segment Routing over IPv6 Dataplane - draft-ietf-lsr-isis-srv6-extensions-06.txt + draft-ietf-lsr-isis-srv6-extensions-07.txt Abstract 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 draft describes the IS-IS extensions required to support Segment Routing over an IPv6 data plane. @@ -38,21 +38,21 @@ 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 September 4, 2020. + This Internet-Draft will expire on September 24, 2020. 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 @@ -73,36 +73,36 @@ 4.3. Maximum H.Encaps 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 . . . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . 15 - 10. Advertising Endpoint Behaviors . . . . . . . . . . . . . . . 16 - 11. Implementation Status . . . . . . . . . . . . . . . . . . . . 17 - 11.1. Cisco . . . . . . . . . . . . . . . . . . . . . . . . . 17 - 11.2. Huawei . . . . . . . . . . . . . . . . . . . . . . . . . 17 + 9. SRv6 SID Structure Sub-Sub-TLV . . . . . . . . . . . . . . . 16 + 10. Advertising Endpoint Behaviors . . . . . . . . . . . . . . . 17 + 11. Implementation Status . . . . . . . . . . . . . . . . . . . . 18 + 11.1. Cisco . . . . . . . . . . . . . . . . . . . . . . . . . 18 + 11.2. Huawei . . . . . . . . . . . . . . . . . . . . . . . . . 18 11.3. Juniper . . . . . . . . . . . . . . . . . . . . . . . . 18 11.4. Interoperability Testing. . . . . . . . . . . . . . . . 18 - 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 - 12.1. SRv6 Locator TLV . . . . . . . . . . . . . . . . . . . . 18 - 12.1.1. SRv6 End SID sub-TLV . . . . . . . . . . . . . . . . 18 + 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 + 12.1. SRv6 Locator TLV . . . . . . . . . . . . . . . . . . . . 19 + 12.1.1. SRv6 End SID sub-TLV . . . . . . . . . . . . . . . . 19 12.1.2. Revised sub-TLV table . . . . . . . . . . . . . . . 19 12.2. SRv6 Capabilities sub-TLV . . . . . . . . . . . . . . . 19 - 12.3. SRv6 End.X SID and SRv6 LAN End.X SID sub-TLVs . . . . . 19 + 12.3. SRv6 End.X SID and SRv6 LAN End.X SID sub-TLVs . . . . . 20 12.4. MSD Types . . . . . . . . . . . . . . . . . . . . . . . 20 - 12.5. Sub-Sub-TLVs for SID Sub-TLVs . . . . . . . . . . . . . 20 - 12.6. Prefix Attribute Flags Sub-TLV . . . . . . . . . . . . . 20 + 12.5. Sub-Sub-TLVs for SID Sub-TLVs . . . . . . . . . . . . . 21 + 12.6. Prefix Attribute Flags Sub-TLV . . . . . . . . . . . . . 21 13. Security Considerations . . . . . . . . . . . . . . . . . . . 21 14. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 21 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 15.1. Normative References . . . . . . . . . . . . . . . . . . 22 15.2. Informative References . . . . . . . . . . . . . . . . . 24 15.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 1. Introduction @@ -256,21 +256,21 @@ As discussed in [I-D.ietf-spring-srv6-network-programming], an SRv6 Segment Identifier (SID) is 128 bits and consists of Locator, Function and Argument parts. A node is provisioned with topology/algorithm specific locators for each of the topology/algorithm pairs supported by that node. Each locator is a covering prefix for all SIDs provisioned on that node which have the matching topology/algorithm. Locators MUST be advertised in the SRv6 Locator TLV (see - Section 6.1). Forwarding entries for the locators advertised in the + Section 7.1). Forwarding entries for the locators advertised in the SRv6 Locator TLV MUST be installed in the forwarding plane of receiving SRv6 capable routers when the associated topology/algorithm is supported by the receiving node. Locators are routable and MAY also be advertised in Prefix Reachability TLVs (236 or 237). Locators associated with Flexible Algorithms [I-D.ietf-lsr-flex-algo] SHOULD NOT be advertised in Prefix Reachability TLVs (236 or 237). @@ -429,21 +429,21 @@ Optional sub-TLVs. 7.2. SRv6 End SID sub-TLV The SRv6 End SID sub-TLV is introduced to advertise SRv6 Segment Identifiers (SID) with Endpoint behaviors which do not require a particular neighbor in order to be correctly applied [I-D.ietf-spring-srv6-network-programming]. SRv6 SIDs associated with a neighbor are advertised using the sub-TLVs defined in - Section 6. + Section 8. This new sub-TLV is advertised in the SRv6 Locator TLV defined in the previous section. SRv6 End SIDs inherit the topology/algorithm from the parent locator. The SRv6 End SID sub-TLV has the following format: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ @@ -455,34 +455,36 @@ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (cont . . .) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (cont . . .) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (cont . . .) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Sub-sub-tlv-len| sub-sub-TLVs (variable) . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Type: 5 (Suggested value to be assigned by IANA) + Type: 5 (Suggested value to be assigned by IANA). Length: variable. Flags: 1 octet. No flags are currently defined. - Endpoint Behavior: 2 octets, as defined in [I-D.ietf-spring-srv6-network-programming]. - Legal behavior values for this sub-TLV are defined in Section 9 of this document. + Endpoint Behavior: 2 octets, as defined in [I-D.ietf-spring-srv6- + network-programming]. Legal behavior values for this sub-TLV are + defined in Section 10 of this document. SID: 16 octets. This field encodes the advertised SRv6 SID. - Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub-TLVs + Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub- + TLVs. - Optional sub-sub-TLVs + Optional sub-sub-TLVs. The SRv6 End SID MUST be a subnet of the associated Locator. SRv6 End SIDs which are NOT a subnet of the associated locator MUST be ignored. Multiple SRv6 End SIDs MAY be associated with the same locator. In cases where the number of SRv6 End SID sub-TLVs exceeds the capacity of a single TLV, multiple Locator TLVs for the same locator MAY be advertised. For a given MTID/Locator the algorithm MUST be the same in all TLVs. If this restriction is not met all TLVs for that MTID/ @@ -536,63 +538,63 @@ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (cont . . .) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (cont . . .) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (cont . . .) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Sub-sub-tlv-len| Sub-sub-TLVs (variable) . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Type: 43 (Suggested value to be assigned by IANA) + Type: 43 (Suggested value to be assigned by IANA). Length: variable. Flags: 1 octet. 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |B|S|P|Reserved | +-+-+-+-+-+-+-+-+ where: - B-Flag: Backup flag. If set, the End.X SID is eligible - for protection (e.g., using IPFRR) as described in [RFC8355]. + B-Flag: Backup flag. If set, the End.X SID is eligible for + protection (e.g., using IPFRR) as described in [RFC8355]. S-Flag. Set flag. When set, the S-Flag indicates that the - End.X SID refers to a set of adjacencies (and therefore - MAY be assigned to other adjacencies as well). + End.X SID refers to a set of adjacencies (and therefore MAY be + assigned to other adjacencies as well). P-Flag. Persistent flag. When set, the P-Flag indicates that - the End.X SID is persistently allocated, i.e., the - End.X SID value remains consistent across router restart - and/or interface flap. + the End.X SID is persistently allocated, i.e., the End.X SID + value remains consistent across router restart and/or interface + flap. Other bits: MUST be zero when originated and ignored when received. - Algorithm: 1 octet. Associated algorithm. Algorithm values - are defined in the IGP Algorithm Type registry. + Algorithm: 1 octet. Associated algorithm. Algorithm values are + defined in the IGP Algorithm Type registry. - Weight: 1 octet. The value represents the weight of the - End.X SID for the purpose of load balancing. The use - of the weight is defined in [I-D.ietf-spring-segment-routing]. + Weight: 1 octet. The value represents the weight of the End.X SID + for the purpose of load balancing. The use of the weight is + defined in [I-D.ietf-spring-segment-routing]. - Endpoint Behavior: 2 octets. As defined in - [I-D.ietf-spring-srv6-network-programming] - Legal behavior values for this sub-TLV are defined in Section 9. + Endpoint Behavior: 2 octets. As defined in [I-D.ietf-spring-srv6- + network-programming] Legal behavior values for this sub-TLV are + defined in Section 10. SID: 16 octets. This field encodes the advertised SRv6 SID. Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub- - TLVs + TLVs. Note that multiple TLVs for the same neighbor may be required in order to advertise all of the SRv6 End.X SIDs associated with that neighbor. 8.2. SRv6 LAN End.X SID sub-TLV This sub-TLV is used to advertise an SRv6 SID associated with a LAN adjacency. Since the parent TLV is advertising an adjacency to the Designated Intermediate System(DIS) for the LAN, it is necessary to @@ -620,47 +622,47 @@ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (cont . . .) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (cont . . .) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID (cont . . .) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Sub-sub-tlv-len| sub-sub-TLVs (variable) . . . | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - Type: 44 (Suggested value to be assigned by IANA) + Type: 44 (Suggested value to be assigned by IANA). + Length: variable. System-ID: 6 octets of IS-IS System-ID of length "ID Length" as defined in [ISO10589]. Flags: 1 octet. 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |B|S|P|Reserved | +-+-+-+-+-+-+-+-+ - where B,S, and P flags are as described in Section 8.1. - Other bits: MUST be zero when originated and ignored when - received. + where B,S, and P flags are as described in Section 8.1. Other + bits: MUST be zero when originated and ignored when received. - Algorithm: 1 octet. Associated algorithm. Algorithm values - are defined in the IGP Algorithm Type registry. + Algorithm: 1 octet. Associated algorithm. Algorithm values are + defined in the IGP Algorithm Type registry. - Weight: 1 octet. The value represents the weight of the - End.X SID for the purpose of load balancing. The use - of the weight is defined in [I-D.ietf-spring-segment-routing]. + Weight: 1 octet. The value represents the weight of the End.X SID + for the purpose of load balancing. The use of the weight is + defined in [I-D.ietf-spring-segment-routing]. - Endpoint Behavior: 2 octets. As defined in - [I-D.ietf-spring-srv6-network-programming] - Legal behavior values for this sub-TLV are defined in Section 9. + Endpoint Behavior: 2 octets. As defined in [I-D.ietf-spring-srv6- + network-programming] Legal behavior values for this sub-TLV are + defined in Section 10. SID: 16 octets. This field encodes the advertised SRv6 SID. Sub-sub-TLV-length: 1 octet. Number of octets used by sub-sub- TLVs. 9. SRv6 SID Structure Sub-Sub-TLV SRv6 SID Structure Sub-Sub-TLV is an optional Sub-Sub-TLV of: @@ -706,23 +708,25 @@ sizes advertised in the ISIS SRv6 SID Structure Sub-Sub-TLV is larger than 128 bits, the parent Sub-TLV MUST be ignored by the receiver. 10. Advertising Endpoint Behaviors Endpoint behaviors are defined in [I-D.ietf-spring-srv6-network-programming] and [I-D.ietf-6man-spring-srv6-oam]. The codepoints for the Endpoint behaviors are defined in the "SRv6 Endpoint Behaviors" registry defined in [I-D.ietf-spring-srv6-network-programming]. This section - lists the Endpoint behaviors and their codepoints, which MAY be - advertised by IS-IS and the SID sub-TLVs in which each type MAY - appear. + lists the Endpoint behaviors which MAY be advertised by ISIS, + together with their codepoints. If this behavior is advertised it + MUST only be advertised in the TLV[s] as indicated by "Y" in the + table below, and MUST NOT be advertised in the TLV[s] as indicated by + "N" in the table below. Endpoint |Endpoint | End | End.X | Lan End.X | Behavior |Behavior Codepoint | SID | SID | SID | -----------------------|--------------------|-------|-------|-----------| End (PSP, USP, USD) | 1-4, 28-31 | Y | N | N | -----------------------|--------------------|-------|-------|-----------| End.X (PSP, USP, USD) | 5-8, 32-35 | N | Y | Y | -----------------------|--------------------|-------|-------|-----------| End.T (PSP, USP, USD) | 9-12, 36-39 | Y | N | N | -----------------------|--------------------|-------|-------|-----------| @@ -754,21 +758,22 @@ Intra/Inter area/level support: Yes Anycast SID support: Yes, including A-flag (Section 6) SID Structure Sub-Sub-TLV: Yes 11.2. Huawei Huawei's ISIS SRv6 implementation supports following functionalities: - Types of SID supported: End, End.X + Types of SID supported: End, End.X, LAN End.X + Intra/Inter area/level support: Yes Anycast SID support: Yes, no A-flag support (Section 6) SID Structure Sub-Sub-TLV: No 11.3. Juniper Juniper's ISIS SRv6 implementation supports following functionalities: @@ -969,21 +976,21 @@ [I-D.ietf-6man-spring-srv6-oam] Ali, Z., Filsfils, C., Matsushima, S., Voyer, D., and M. Chen, "Operations, Administration, and Maintenance (OAM) in Segment Routing Networks with IPv6 Data plane (SRv6)", draft-ietf-6man-spring-srv6-oam-03 (work in progress), December 2019. [I-D.ietf-spring-srv6-network-programming] Filsfils, C., Camarillo, P., Leddy, J., Voyer, D., Matsushima, S., and Z. Li, "SRv6 Network Programming", - draft-ietf-spring-srv6-network-programming-11 (work in + draft-ietf-spring-srv6-network-programming-14 (work in progress), March 2020. [ISO10589] Standardization", I. ". O. F., "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, Second Edition.", Nov 2002. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate