idnits 2.17.1 draft-peng-lsr-flex-algo-l2bundles-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 : ---------------------------------------------------------------------------- No issues found here. 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 'MAY NOT' 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. == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'SHOULD not' in this paragraph: For example, three Flex-algo plane share the same Layer 3 parrent interface including three L2 Bundle Members each with color "RED", "GREEN", "BLUE" respectively, and each Flex-algo plane with link selection rule "Include-Any RED", "Include-Any GREEN", "Include-Any BLUE" respectively, Flex-algo SHOULD not simply select the Layer 3 parrent interface to all Flex-algo plane, but need continue to select individual L2 Bundle Member to the specific Flex-algo plane. As a reslut, the FIB entry within Flex-algo RED plane will exactly choose the L2 Bundle Members with color "RED" to forward packets, the FIB entry within Flex-algo GREEN plane will exactly choose the L2 Bundle Members with color "GREEN" to forward packets, and the FIB entry within Flex-algo BLUE plane will exactly choose the L2 Bundle Members with color "BLUE" to forward packets. == The expression 'MAY NOT', while looking like RFC 2119 requirements text, is not defined in RFC 2119, and should not be used. Consider using 'MUST NOT' instead (if that is what you mean). Found 'MAY NOT' in this paragraph: "ISIS L2 Bundle Member EAG sub-TLV" MAY NOT appear more then once in TLV-25. If it appears more then once, the first one is valid. -- The document date (December 30, 2019) is 1569 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) == Unused Reference: 'RFC4915' is defined on line 267, but no explicit reference was found in the text == Unused Reference: 'RFC5120' is defined on line 272, but no explicit reference was found in the text == Unused Reference: 'RFC5340' is defined on line 278, but no explicit reference was found in the text == Unused Reference: 'RFC8402' is defined on line 286, but no explicit reference was found in the text == Outdated reference: A later version (-26) exists of draft-ietf-lsr-flex-algo-05 == Outdated reference: A later version (-02) exists of draft-ketant-lsr-ospf-l2bundles-00 Summary: 0 errors (**), 0 flaws (~~), 9 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 L P. Shaofu 3 Internet-Draft C. Ran 4 Intended status: Standards Track ZTE Corporation 5 Expires: July 2, 2020 G. Mirsky 6 ZTE Corp. 7 December 30, 2019 9 IGP Flexible Algorithm with L2bundles 10 draft-peng-lsr-flex-algo-l2bundles-00 12 Abstract 14 IGP Flex Algorithm proposes a solution that allows IGPs themselves to 15 compute constraint based paths over the network, and it also 16 specifies a way of using Segment Routing (SR) Prefix-SIDs and SRv6 17 locators to steer packets along the constraint-based paths. This 18 document describes how to create Flex-algo plane with L2bundles 19 scenario. 21 Status of This Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at https://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on July 2, 2020. 38 Copyright Notice 40 Copyright (c) 2019 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents 45 (https://trustee.ietf.org/license-info) in effect on the date of 46 publication of this document. Please review these documents 47 carefully, as they describe your rights and restrictions with respect 48 to this document. Code Components extracted from this document must 49 include Simplified BSD License text as described in Section 4.e of 50 the Trust Legal Provisions and are provided without warranty as 51 described in the Simplified BSD License. 53 Table of Contents 55 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 56 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 57 3. Color set on L2 Bundle Member . . . . . . . . . . . . . . . . 3 58 4. Flex-algo plane with L2 link resource . . . . . . . . . . . . 3 59 4.1. Best-effort . . . . . . . . . . . . . . . . . . . . . . . 3 60 4.2. Traffic Engineering . . . . . . . . . . . . . . . . . . . 4 61 5. IGP L2 Bundle Member EAG Extensions . . . . . . . . . . . . . 4 62 5.1. ISIS L2 Bundle Member EAG Extension . . . . . . . . . . . 4 63 5.2. OSPF L2 Bundle Member EAG Extension . . . . . . . . . . . 5 64 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 65 6.1. ISIS IANA Considerations . . . . . . . . . . . . . . . . 6 66 7. Security Considerations . . . . . . . . . . . . . . . . . . . 6 67 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 68 9. Normative References . . . . . . . . . . . . . . . . . . . . 6 69 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 71 1. Introduction 73 IGP Flex Algorithm [I-D.ietf-lsr-flex-algo] proposes a solution that 74 allows IGPs themselves to compute constraint based paths over the 75 network, and it also specifies a way of using Segment Routing (SR) 76 Prefix-SIDs and SRv6 locators to steer packets along the constraint- 77 based paths. It specifies a set of extensions to ISIS, OSPFv2 and 78 OSPFv3 that enable a router to send TLVs that identify (a) 79 calculation-type, (b) specify a metric-type, and (c )describe a set 80 of constraints on the topology, that are to be used to compute the 81 best paths along the constrained topology. A given combination of 82 calculation-type, metric-type, and constraints is known as an FAD 83 (Flexible Algorithm Definition). 85 [RFC8668] and [I-D.ketant-lsr-ospf-l2bundles] introduces the ability 86 for IS-IS and OSPF respectively to advertise the link attributes of 87 Layer 2 (L2) Bundle Members. Especially, the link attribute 88 "Administrative Group" and "Extended Administrative Group" could be 89 individual to each L2 Bundle Member for purpose of Flex-algo plane 90 construction, where multiple Flex-algo planes share the same Layer 3 91 parent interface and each Flex-algo plane has dedicated L2 Bundle 92 Member. 94 This document describes how to create Flex-algo plane with L2bundles 95 scenario. 97 2. Requirements Language 99 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 100 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 101 "OPTIONAL" in this document are to be interpreted as described in BCP 102 14 [RFC2119] [RFC8174] when, and only when, they appear in all 103 capitals, as shown here. 105 3. Color set on L2 Bundle Member 107 Traffic Engineering affinity (also termed as Color) is often to be 108 set on the Layer 3 interface and be flooded by IGP-TE. However, when 109 the Layer 3 interface is a Layer 2 interface bundle, operators can 110 config individual color for each L2 Bundle Member. So that IGP link- 111 state database will contain the TE affinity attribute of L2 Bundle 112 Member, as well as Layer 3 parrent interface. 114 Note that Layer 3 interface can join to IGP instance explicitly, but 115 L2 Bundle Member not. 117 The TE affinity of the Layer 3 parrent interface can be a combined 118 value of all L2 Bundle Members. For example, if the Layer 3 parrent 119 interface contains three L2 Bundle Members, each with color "RED", 120 "GREEN", "BLUE" respectively, the Layer 3 parrent interface will have 121 color "RED|GREEN|BLUE". 123 4. Flex-algo plane with L2 link resource 125 4.1. Best-effort 127 [I-D.ietf-lsr-flex-algo] defines the color-based link resource 128 selection rules in FAD to construct the expected Flex-algo plane. 129 Each node in the Flex-algo plane will establish the SPT with self as 130 root node, to maintain the best path to other nodes and get the FIB 131 entry based on that. The root node need check the outgoing Layer 2 132 interface bundle interface, to see which L2 Bundle Member does 133 exactly belong to the Flex-algo plane. The forwarding information of 134 the FIB entry with outgoing Layer 2 interface bundle interface will 135 exactly select the L2 Bundle Member that belongs to the Flex-algo 136 plane to forward packets. 138 For example, three Flex-algo plane share the same Layer 3 parrent 139 interface including three L2 Bundle Members each with color "RED", 140 "GREEN", "BLUE" respectively, and each Flex-algo plane with link 141 selection rule "Include-Any RED", "Include-Any GREEN", "Include-Any 142 BLUE" respectively, Flex-algo SHOULD not simply select the Layer 3 143 parrent interface to all Flex-algo plane, but need continue to select 144 individual L2 Bundle Member to the specific Flex-algo plane. As a 145 reslut, the FIB entry within Flex-algo RED plane will exactly choose 146 the L2 Bundle Members with color "RED" to forward packets, the FIB 147 entry within Flex-algo GREEN plane will exactly choose the L2 Bundle 148 Members with color "GREEN" to forward packets, and the FIB entry 149 within Flex-algo BLUE plane will exactly choose the L2 Bundle Members 150 with color "BLUE" to forward packets. 152 4.2. Traffic Engineering 154 A segment list contains SIDs advertised specifically for the given 155 algorithm is possible, such as an inter-domain path contains multiple 156 Flex-algo planes, a TI-LFA backup path within the Flex-algo plane, or 157 an optimized TE path avoiding congested link within the Flex-algo 158 plane. In these cases, an Adjacency segment could be used to steer 159 the packets along the expected L2 Bundle Member that belongs to the 160 specific Flex-algo plane. 162 [RFC8668] and [I-D.ketant-lsr-ospf-l2bundles] have defined Adjacency- 163 SID for each L2 Bundle Member, that can be used to isolate flows 164 among multiple Flex-algo planes, when these Flex-algo planes share 165 the same Layer 3 parrent interface. A specific Adjacency-SID for a 166 specific L2 Bundle Member will steer the packets to that member. 168 5. IGP L2 Bundle Member EAG Extensions 170 5.1. ISIS L2 Bundle Member EAG Extension 172 [RFC8668] defined TLV-25 for ISIS to advertise the link attributes of 173 L2 Bundle Members, and mentioned that the traditional "Administrative 174 group (color) Sub-TLV" and "Extended Administrative Group Sub-TLV" 175 may appear in TLV-25 and MAY be shared by multiple L2 Bundle Members. 176 For individual EAG attributes of L2 Bundle Member purpose, this 177 document defines a new "ISIS L2 Bundle Member EAG sub-TLV". It has 178 the following format: 180 0 1 2 3 181 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 1 182 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 | Type | Length | 184 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 | Extended Admin Group of L2 Bundle Member 1 | 186 +- -+ 187 | ... | 188 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 | Extended Admin Group of L2 Bundle Member 2 | 190 +- -+ 191 | ... | 192 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 | ... ... | 194 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 195 | Extended Admin Group of L2 Bundle Member N | 196 +- -+ 197 | ... | 198 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 200 Figure 1: ISIS L2 Bundle Member EAG sub-TLV format 202 where: 204 Type: TBD1. 206 Length: 4 octets, it give the total length of EAG information of all 207 members. 209 Extended Admin Group of L2 Bundle Member: for each L2 Bundle Member 210 there is an EAG value. Note that "L2 Bundle Member Attributes sub- 211 TLV" explicitly give how many L2 Bundle Members there are and list 212 each L2 Bundle Member Identifier in order, thus in "ISIS L2 Bundle 213 Member EAG sub-TLV" there MUST be an EAG value for each L2 Bundle 214 Member in the same order. 216 "ISIS L2 Bundle Member EAG sub-TLV" MAY NOT appear more then once in 217 TLV-25. If it appears more then once, the first one is valid. 219 5.2. OSPF L2 Bundle Member EAG Extension 221 [I-D.ketant-lsr-ospf-l2bundles] defined "L2 Bundle Member Attributes 222 sub-TLV" for OSPF/OSPFv3 to advertise the link attributes of L2 223 Bundle Members, and mentioned that the traditional "Administrative 224 group (color) Sub-TLV" and "Extended Administrative Group Sub-TLV" 225 are applicable in "L2 Bundle Member Attributes sub-TLV". Because 226 there is "L2 Bundle Member Attributes sub-TLV" per L2 Bundle Member, 227 it is sufficient to construct Flex-algo plane to select L2 link 228 resource. 230 6. IANA Considerations 232 6.1. ISIS IANA Considerations 234 This document adds the following new sub-TLV to the ISIS TLV-25 235 registry. 237 Type: TBD1 239 Description: ISIS L2 Bundle Member Extended Administrative Group 241 7. Security Considerations 243 There are no new security issues introduced by the extensions in this 244 document. 246 8. Acknowledgements 248 TBD 250 9. Normative References 252 [I-D.ietf-lsr-flex-algo] 253 Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and 254 A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex- 255 algo-05 (work in progress), November 2019. 257 [I-D.ketant-lsr-ospf-l2bundles] 258 Talaulikar, K. and P. Psenak, "Advertising L2 Bundle 259 Member Link Attributes in OSPF", draft-ketant-lsr-ospf- 260 l2bundles-00 (work in progress), July 2019. 262 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 263 Requirement Levels", BCP 14, RFC 2119, 264 DOI 10.17487/RFC2119, March 1997, 265 . 267 [RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P. 268 Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF", 269 RFC 4915, DOI 10.17487/RFC4915, June 2007, 270 . 272 [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi 273 Topology (MT) Routing in Intermediate System to 274 Intermediate Systems (IS-ISs)", RFC 5120, 275 DOI 10.17487/RFC5120, February 2008, 276 . 278 [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF 279 for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008, 280 . 282 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 283 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 284 May 2017, . 286 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 287 Decraene, B., Litkowski, S., and R. Shakir, "Segment 288 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 289 July 2018, . 291 [RFC8668] Ginsberg, L., Ed., Bashandy, A., Filsfils, C., Nanduri, 292 M., and E. Aries, "Advertising Layer 2 Bundle Member Link 293 Attributes in IS-IS", RFC 8668, DOI 10.17487/RFC8668, 294 December 2019, . 296 Authors' Addresses 298 Peng Shaofu 299 ZTE Corporation 300 No.68 Zijinghua Road, Yuhuatai District 301 Nanjing 302 China 304 Email: peng.shaofu@zte.com.cn 306 Chen Ran 307 ZTE Corporation 308 No.50 Software Avenue, Yuhuatai District 309 Nanjing 310 China 312 Email: chen.ran@zte.com.cn 314 Greg Mirsky 315 ZTE Corp. 317 Email: gregimirsky@gmail.com