idnits 2.17.1 draft-bonica-spring-srv6-end-dtm-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** There are 3 instances of too long lines in the document, the longest one being 12 characters in excess of 72. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The exact meaning of the all-uppercase expression 'NOT REQUIRED' is not defined in RFC 2119. If it is intended as a requirements expression, it should be rewritten using one of the combinations defined in RFC 2119; otherwise it should not be all-uppercase. -- The document date (January 8, 2021) is 1197 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) No issues found here. Summary: 1 error (**), 0 flaws (~~), 1 warning (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 SPRING Working Group S. Hegde 3 Internet-Draft K. Vairavakkalai 4 Intended status: Standards Track R. Bonica 5 Expires: July 12, 2021 Juniper Networks 6 January 8, 2021 8 The SRv6 END.DTM Segment Type 9 draft-bonica-spring-srv6-end-dtm-00 11 Abstract 13 This document describes a new SRv6 segment type, called END.DTM. The 14 END.DTM segment type supports inter-working between SRv6 and SR-MPLS. 15 Like any segment type, END.DTM contains a function and arguments. 16 The function causes the processing SRv6 node to remove an SRv6 header 17 and impose an SR-MPLS label stack. The arguments determine MPLS- 18 label stack contents. 20 Status of This Memo 22 This Internet-Draft is submitted in full conformance with the 23 provisions of BCP 78 and BCP 79. 25 Internet-Drafts are working documents of the Internet Engineering 26 Task Force (IETF). Note that other groups may also distribute 27 working documents as Internet-Drafts. The list of current Internet- 28 Drafts is at https://datatracker.ietf.org/drafts/current/. 30 Internet-Drafts are draft documents valid for a maximum of six months 31 and may be updated, replaced, or obsoleted by other documents at any 32 time. It is inappropriate to use Internet-Drafts as reference 33 material or to cite them other than as "work in progress." 35 This Internet-Draft will expire on July 12, 2021. 37 Copyright Notice 39 Copyright (c) 2021 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (https://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 2 55 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 2 56 3. Use-case . . . . . . . . . . . . . . . . . . . . . . . . . . 3 57 4. Processing . . . . . . . . . . . . . . . . . . . . . . . . . 4 58 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 59 6. Security Considerations . . . . . . . . . . . . . . . . . . . 5 60 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 61 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 62 8.1. Normative References . . . . . . . . . . . . . . . . . . 5 63 8.2. Informative References . . . . . . . . . . . . . . . . . 6 64 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 66 1. Overview 68 Segment Routing (SR) [RFC8402] allows source nodes to steer packets 69 through SR paths. It can be implemented over IPv6 [RFC8200] or MPLS 70 [RFC3031]. When SR is implemented over IPv6, it is called SRv6 71 [I-D.ietf-spring-srv6-network-programming]. When SR is implemented 72 over MPLS, it is called SR-MPLS [RFC8660]. 74 This document describes a new SRv6 segment type, called END.DTM. The 75 END.DTM segment type supports inter-working between SRv6 and SR-MPLS. 76 Like any segment type, END.DTM contains a function and arguments. 77 The function causes the processing SRv6 node to: 79 o Remove an SRv6 header (i.e., an IPv6 header and its extensions). 81 o Impose an SR-MPLS label stack. 83 The arguments determine MPLS-label stack contents and Transport Class 84 of the MPLS Tunnel. 86 2. Requirements Language 88 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 89 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 90 "OPTIONAL" in this document are to be interpreted as described in BCP 91 14 [RFC2119] [RFC8174] when, and only when, they appear in all 92 capitals, as shown here. 94 3. Use-case 96 ------ ------ ------ ------ ------ 97 |Node 1| --- |Node 2| --- |Node 3| --- |Node 4| --- |Node 5| 98 ------ ------ ------ ------ ------ 100 Seg. A Seg. B Seg. C Seg. D 102 <-----------SRv6 Part ----------><-------SR-MPLS Part------> 104 Figure 1: END.DTM Use-case 106 Figure 1 depicts an inter-working SR path. The SR path originates on 107 Node 1 and terminates on Node 5. It contains: 109 o An SRv6 part 111 o An SR-MPLS part 113 The SRv6 part includes Nodes 1, 2 and 3. These nodes MUST be 114 SRv6-capable but are NOT REQUIRED to be SR-MPLS capable. An END.DTM 115 segment is instantiated on Node 3. Therefore, Node 3 MUST be able to 116 push an SR-MPLS label stack. However, it is NOT REQUIRED to process 117 incoming MPLS labels. 119 The SRv6 part also includes: 121 o Segment A - An END segment that is instantiated on Node 2. 123 o Segment B - An END.DTM segment that is instantiated on Node 3. 125 The SR-MPLS part includes Nodes 4 and 5. These nodes MUST be SR- 126 MPLS-capable but are NOT REQUIRED to be SRv6 capable. 128 The SR-MPLS part also includes: 130 o Segment C - A prefix segment that is instantiated on Node 4. 132 o Segment D - A prefix segment that is instantiated on Node 5. 134 The following paragraphs describe how a packet traverses this inter- 135 working SR path: 137 Node 1 encapsulates the packet in an SRv6 header. The SRv6 header 138 contains the following Segment Identifiers (SID): 140 o A SID representing Segment A, encoded in the Destination Address 141 field of the IPv6 header. 143 o A SID representing Segment B, encoded in a Segment Routing Header 144 (SRH) [RFC8754]. 146 Node 1 sends the packet to Node 2. When the packet arrives at Node 147 2, The Destination Address field in the IPv6 header represents a 148 locally instantiated END SID. Node 2 processes the packet as 149 follows: 151 o Decrement the Segments Left field in the SRH 153 o Copy the next SID from the SRH to the Destination Address field of 154 the IPv6 header. 156 o Forward the packet to Node 3. 158 When the packet arrives at Node 3, The Destination Address field in 159 the IPv6 header represents a locally instantiated END.DTM SID. Node 160 3 processes the packet as follows: 162 o Remove the IPv6 header and its extension headers (including the 163 SRH). 165 o Push two SR-MPLS labels, representing Segments D and C. 167 o Forward the packet to Node 4. 169 When the packet arrives at Node 4, it is encapsulated in an SR-MPLS 170 label stack. Node 4 processes the packet as described in SR-MPLS 171 [RFC8660]. 173 4. Processing 175 The End.DTM SID MUST be the last segment in a SR Policy. A SID 176 instance is associated with: 178 o An SR-MPLS label stack. 180 o An outbound interface. 182 When Node N receives a packet destined to S and S is a locally 183 instantiated End.DTM SID, Node N executes the following procedure: 185 S01. When an IPv6 Routing Header is processed { 186 S02. If (Segments Left != 0) { 187 S03. Send an ICMP Parameter Problem to the Source Address, 188 Code 0 (Erroneous header field encountered), 189 Pointer set to the Segments Left field, 190 interrupt packet processing and discard the packet. 191 S04. } 192 S05. Proceed to process the next header in the packet 193 S06. } 195 When processing the Upper-layer header of a packet matching a FIB 196 entry locally instantiated as an End.DTM SID, N executes the following procedure: 198 S01. Remove the outer IPv6 Header with all its extension headers 199 S02. Push the SR-MPLS label stack that is associated with the END.DTM instance 200 S03. Send the packet on the out interface associated with the END.DTM instance 202 5. IANA Considerations 204 IANA is requested to add the following entry to the "SRv6 Endpoint 205 Behaviors" sub-registry of the "Segment Routing Parameters" registry: 207 +-------+-----+-------------------+-----------+ 208 | Value | Hex | Endpoint behavior | Reference | 209 +-------+-----+-------------------+-----------+ 210 | TBD | TBD | END.DTM | [This.ID] | 211 +-------+-----+-------------------+-----------+ 213 6. Security Considerations 215 Because SR inter-working requires co-operation between inter-working 216 domains, this document introduces no security consideration beyond 217 those addressed in [RFC8402], [RFC8754] and 218 [I-D.ietf-spring-srv6-network-programming]. 220 7. Acknowledgements 222 TBD 224 8. References 226 8.1. Normative References 228 [I-D.ietf-spring-srv6-network-programming] 229 Filsfils, C., Camarillo, P., Leddy, J., Voyer, D., 230 Matsushima, S., and Z. Li, "SRv6 Network Programming", 231 draft-ietf-spring-srv6-network-programming-28 (work in 232 progress), December 2020. 234 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 235 Requirement Levels", BCP 14, RFC 2119, 236 DOI 10.17487/RFC2119, March 1997, 237 . 239 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 240 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 241 May 2017, . 243 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 244 (IPv6) Specification", STD 86, RFC 8200, 245 DOI 10.17487/RFC8200, July 2017, 246 . 248 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 249 Decraene, B., Litkowski, S., and R. Shakir, "Segment 250 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 251 July 2018, . 253 [RFC8660] Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S., 254 Decraene, B., Litkowski, S., and R. Shakir, "Segment 255 Routing with the MPLS Data Plane", RFC 8660, 256 DOI 10.17487/RFC8660, December 2019, 257 . 259 [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J., 260 Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header 261 (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, 262 . 264 8.2. Informative References 266 [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol 267 Label Switching Architecture", RFC 3031, 268 DOI 10.17487/RFC3031, January 2001, 269 . 271 Authors' Addresses 272 Shraddha Hegde 273 Juniper Networks 274 Embassy Business Park 275 Bangalore, KA 560093 276 India 278 Email: shraddha@juniper.net 280 Kaliraj Vairavakkalai 281 Juniper Networks 282 1133 Innovation Way, 283 Sunnyvale, California 94089 284 USA 286 Email: kaliraj@juniper.net 288 Ron Bonica 289 Juniper Networks 290 Herndon, Virginia 20171 291 USA 293 Email: rbonica@juniper.net