idnits 2.17.1 draft-ietf-isis-layer2-04.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 4 instances of too long lines in the document, the longest one being 8 characters in excess of 72. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == Line 2397 has weird spacing: '...d Flags sub-T...' == Line 2398 has weird spacing: '...d-VLANs sub-...' == Line 2403 has weird spacing: '...ntifier sub-T...' == Line 2415 has weird spacing: '...-Groups sub-...' == Line 2425 has weird spacing: '... Metric sub-...' == 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: The TRILL-Hello PDU has the same general structure as an IS-IS LAN PDU. An RBridge (an Intermediate System supporting TRILL) sends this PDU, with the same timing as the IS-IS LAN Hello PDU. More specifically, in a TRILL-Hello PDU the IS-IS Common Header and the fixed PDU Header are the same as a Level 1 IS-IS LAN Hello except that a new PDU Type number is used as listed in Section 5. The circuit type field, of course, is always equal to one. A TRILL-Hello PDU SHOULD not be padded and MUST NOT exceed a length limit equal to 42 bytes shorter than the reasonable lower bound for the link MTU. For example, for an 802.3 Ethernet link, the MTU SHOULD be assumed to be 1512 bytes for the purpose of determining the maximum size of TRILL-Hello PDUs on that link. Thus, for such a link, TRILL-Hellos MUST NOT exceed 1470 bytes. -- The document date (April 16, 2010) is 5121 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) == Missing Reference: 'RFC1195' is mentioned on line 132, but not defined == Missing Reference: 'TBD' is mentioned on line 2181, but not defined == Missing Reference: 'RFC5305' is mentioned on line 1886, but not defined == Missing Reference: 'RFC 5226' is mentioned on line 2434, but not defined ** Obsolete undefined reference: RFC 5226 (Obsoleted by RFC 8126) == Unused Reference: 'RFC 1195' is defined on line 2445, but no explicit reference was found in the text == Unused Reference: 'RFC 5305' is defined on line 2454, but no explicit reference was found in the text -- Possible downref: Non-RFC (?) normative reference: ref. 'IS-IS' ** Obsolete normative reference: RFC 4971 (Obsoleted by RFC 7981) ** Obsolete normative reference: RFC 5306 (Obsoleted by RFC 8706) == Outdated reference: A later version (-04) exists of draft-hasmit-otv-00 Summary: 4 errors (**), 0 flaws (~~), 14 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group A. Banerjee, Ed. 3 Internet-Draft Cisco Systems 4 Intended status: Standards Track D. Ward 5 Expires: October 18, 2010 Juniper Networks 6 R. White 7 D. Farinacci 8 Cisco Systems 9 R. Perlman 10 Intel Labs 11 D. Eastlake 12 Stellar Switches 13 P. Ashwood-Smith 14 Huawei 15 D. Fedyk 16 Alcatel-Lucent 17 April 16, 2010 19 Extensions to IS-IS for Layer-2 Systems 20 draft-ietf-isis-layer2-04 22 Abstract 24 This document specifies the IS-IS extensions necessary to support 25 multi-link IPv4 and IPv6 networks, as well as to provide true link 26 state routing to any protocols running directly over layer 2. While 27 supporting this concept involves several pieces, this document only 28 describes extensions to IS-IS. We leave it to the systems using 29 these IS-IS extensions to explain how the information carried in 30 IS-IS is used. 32 Status of this Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at http://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on October 18, 2010. 49 Copyright Notice 51 Copyright (c) 2010 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents 56 (http://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with respect 59 to this document. Code Components extracted from this document must 60 include Simplified BSD License text as described in Section 4.e of 61 the Trust Legal Provisions and are provided without warranty as 62 described in the Simplified BSD License. 64 Table of Contents 66 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 67 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 68 2. PDU, TLV and sub-TLV Enhancements to IS-IS . . . . . . . . . . 5 69 2.1. The MAC-Reachability TLV . . . . . . . . . . . . . . . . . 5 70 2.2. The Group Address TLV . . . . . . . . . . . . . . . . . . 6 71 2.2.1. The Group MAC Address sub-TLV . . . . . . . . . . . . 6 72 2.2.2. The Group IP Address sub-TLV . . . . . . . . . . . . . 8 73 2.2.3. The Group IPv6 Address sub-TLV . . . . . . . . . . . . 10 74 2.2.4. The SPBV MAC Address sub-TLV . . . . . . . . . . . . . 12 75 2.3. Multi Topology aware Port Capability TLV . . . . . . . . . 14 76 2.3.1. The Special VLANs and Flags sub-TLV . . . . . . . . . 14 77 2.3.2. Enabled VLANs sub-TLV . . . . . . . . . . . . . . . . 16 78 2.3.3. Appointed Forwarders sub-TLV . . . . . . . . . . . . . 17 79 2.3.4. Hop-by-Hop Options (HBHOPT) sub-TLV . . . . . . . . . 18 80 2.3.5. Base VLAN-Identifiers sub-TLV . . . . . . . . . . . . 19 81 2.3.6. SPB Digest sub-TLV . . . . . . . . . . . . . . . . . . 20 82 2.3.7. Site Identifier sub-TLV . . . . . . . . . . . . . . . 21 83 2.3.8. Site Group IPv4 sub-TLV . . . . . . . . . . . . . . . 22 84 2.3.9. Site Group IPv6 sub-TLV . . . . . . . . . . . . . . . 23 85 2.3.10. Adjacency Server IPv4 sub-TLV . . . . . . . . . . . . 23 86 2.3.11. Adjacency Server IPv6 sub-TLV . . . . . . . . . . . . 24 87 2.4. Sub-TLVs for the Router Capability TLV . . . . . . . . . . 25 88 2.4.1. The TRILL Version sub-TLV . . . . . . . . . . . . . . 25 89 2.4.2. The Nickname sub-TLV . . . . . . . . . . . . . . . . . 26 90 2.4.3. The Trees sub-TLV . . . . . . . . . . . . . . . . . . 27 91 2.4.4. The Tree Identifiers Sub-TLV . . . . . . . . . . . . . 28 92 2.4.5. The Trees Used Identifiers Sub-TLV . . . . . . . . . . 29 93 2.4.6. Interested VLANs and Spanning Tree Roots sub-TLV . . . 29 94 2.4.7. The VLAN Group sub-TLV . . . . . . . . . . . . . . . . 31 95 2.4.8. The Ingress-to-Egress Options (ITEOPT) sub-TLV . . . . 32 96 2.4.9. VLAN Mapping (VMAP) sub-TLV . . . . . . . . . . . . . 33 97 2.5. Multi Topology Aware Capability TLV . . . . . . . . . . . 34 98 2.5.1. SPB Instance sub-TLV . . . . . . . . . . . . . . . . . 35 99 2.5.2. SPBM Service Identifier and Unicast Address sub-TLV . 38 100 2.6. Sub-TLVs of the Extended Reachability TLV . . . . . . . . 39 101 2.6.1. SPB Link Metric sub-TLV . . . . . . . . . . . . . . . 39 102 2.6.2. MTU sub-TLV . . . . . . . . . . . . . . . . . . . . . 40 103 2.7. TRILL Neighbor TLV . . . . . . . . . . . . . . . . . . . . 41 104 2.8. The Group Membership Active Source TLV . . . . . . . . . . 42 105 2.8.1. The Group MAC Active Source sub-TLV . . . . . . . . . 43 106 2.8.2. The Group IP Active Source sub-TLV . . . . . . . . . . 44 107 2.8.3. The Group IPv6 Active Source sub-TLV . . . . . . . . . 46 108 2.9. PDU Extensions to IS-IS . . . . . . . . . . . . . . . . . 48 109 2.9.1. The Multicast Group PDU . . . . . . . . . . . . . . . 48 110 2.9.2. The Multicast Group Partial Sequence Number PDU . . . 49 111 2.9.3. The Multicast Group Complete Sequence Number PDU . . . 49 112 2.9.4. MGROUP PDU related changes to Base protocol . . . . . 49 113 2.9.4.1. Enhancements to the flooding process . . . . . . . 50 114 2.9.4.2. Enhancements to Graceful Restart . . . . . . . . . 50 115 2.9.4.3. Enhancements to the maximum sequence number 116 reached . . . . . . . . . . . . . . . . . . . . . 50 117 2.9.4.4. Enhancements to the SPF . . . . . . . . . . . . . 51 118 2.9.5. The TRILL-Hello PDU . . . . . . . . . . . . . . . . . 51 119 2.9.6. The MTU PDU . . . . . . . . . . . . . . . . . . . . . 51 120 3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 53 121 4. Security Considerations . . . . . . . . . . . . . . . . . . . 54 122 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 55 123 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 58 124 6.1. Normative References . . . . . . . . . . . . . . . . . . . 58 125 6.2. Informative References . . . . . . . . . . . . . . . . . . 58 126 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 59 128 1. Overview 130 There are a number of systems (for example, [RBRIDGES], [802.1aq], 131 [OTV]) that use layer 2 addresses carried in a link state routing 132 protocol, specifically IS-IS [IS-IS] [RFC1195], to provide true layer 133 2 routing. This document specifies a set of TLVs and sub-TLVs to be 134 added to [IS-IS] level 1 PDUs, and six new PDU types, to support 135 these proposed systems. Some of these TLVs are generic layer 2 136 additions and some are specific to [RBRIDGES] or [802.1aq] or [OTV]. 137 This draft does not propose any new forwarding mechanisms using this 138 additional information carried within IS-IS. 140 This document specifies additional TLVs and sub-TLVs, to carry 141 unicast and multicast attached address information. It also 142 specifies additional TLVs and sub-TLVs to carry information as 143 required by the IETF TRILL and IEEE 802.1aq protocols. 145 This document specifies six new IS-IS PDUs. The Multicast Group 146 (MGROUP) PDU, for carrying a list of attached or joined multicast 147 groups. The Multicast Group Complete Sequence Number (MGROUP-CSNP) 148 PDU and the Multicast Group Partial Sequence Number (MGROUP-PSNP) PDU 149 packets are also defined to be used with the new MGROUP-PDU to 150 perform database exchange on the MGROUP PDUs. The TRILL-Hello PDU 151 provides the subnet specific layer of IS-IS for TRILL links. The 152 MTU-probe and MTU-ack PDUs provide a means of testing link MTU. 154 1.1. Terminology 156 The term "Hello" or "Hello PDU" in this document, when not further 157 qualified, includes the TRILL IIH PDU, the LAN IIH PDU and the P2P 158 IIH PDU. 160 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 161 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 162 document are to be interpreted as described in RFC 2119. 164 2. PDU, TLV and sub-TLV Enhancements to IS-IS 166 In this section we specify the enhancements for the PDUs, TLVs and 167 sub-TLVs as needed by Layer-2 technologies. 169 2.1. The MAC-Reachability TLV 171 The MAC-Reachability (MAC-RI) TLV is IS-IS TLV type 141 and has the 172 following format: 174 +-+-+-+-+-+-+-+-+ 175 | Type= MAC-RI | (1 byte) 176 +-+-+-+-+-+-+-+-+ 177 | Length | (1 byte) 178 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 179 | Topology-Id/ Nickname | (2 bytes) 180 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 181 | Confidence | (1 byte) 182 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 | RESV | VLAN-ID | (2 bytes) 184 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 | MAC (1) (6 bytes) | 186 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 | ................. | 188 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 | MAC (N) (6 bytes) | 190 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 192 o Type: TLV Type, set to 141 (MAC-RI). 194 o Length: Total number of bytes contained in the value field given 195 by 5 + 6*n bytes. 197 o Topology-Id/Nickname : Depending on the technology in which it is 198 used, this carries the topology-id or nickname. When this field 199 is set to zero this implies that the MAC addresses are reachable 200 across all topologies or across all nicknames of the originating 201 IS. 203 o Confidence: This carries an 8-bit quantity indicating the 204 confidence level in the MAC addresses being transported. Whether 205 this field is used, and its semantics if used, are further defined 206 by the specific protocol using Layer-2-IS-IS. If not used, it 207 MUST be set to zero on transmission and be ignored on receipt. 209 o RESV: Must be sent as zero on transmission and is ignored on 210 receipt. 212 o VLAN-ID: This carries a 12-bit VLAN identifier that is valid for 213 all subsequent MAC addresses in this TLV, or the value zero if no 214 VLAN is specified. 216 o MAC(i): This is the 48-bit MAC address reachable from the IS that 217 is announcing this TLV. 219 The MAC-RI TLV is carried in a standard Level 1 link state PDU. It 220 MUST contain only unicast addresses. 222 2.2. The Group Address TLV 224 The Group Address (GADDR) TLV is IS-IS TLV type 142 [TBD] and has the 225 following format: 227 +-+-+-+-+-+-+-+-+ 228 | Type=GADDRTLV | (1 byte) 229 +-+-+-+-+-+-+-+-+ 230 | Length | (1 byte) 231 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 232 | sub-TLVs (variable bytes) | 233 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 235 o Type: TLV Type, set to GADDR-TLV 142 [TBD]. 237 o Length: Total number of bytes contained in the value field, which 238 includes the length of the sub-TLVs carried in this TLV. 240 o sub-TLVs: The Group Address TLV value contains sub-TLVs formatted 241 as described in [RFC5305]. The sub-TLVs for this TLV are 242 specified in the following subsections. 244 The GADDR TLV is carried only within a Multicast Group Level 1 link 245 state PDU. 247 2.2.1. The Group MAC Address sub-TLV 249 The Group MAC Address (GMAC-ADDR) sub-TLV is IS-IS sub-TLV type 1 250 within the GADDR TLV and has the following format: 252 +-+-+-+-+-+-+-+-+ 253 | Type=GMAC-ADDR| (1 byte) 254 +-+-+-+-+-+-+-+-+ 255 | Length | (1 byte) 256 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 257 | Topology-Id/ Nickname | (2 bytes) 258 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 259 | Confidence | (1 byte) 260 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 261 | RESV | VLAN-ID | (2 bytes) 262 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 263 |Num Group Recs | (1 byte) 264 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 265 | GROUP RECORDS (1) | 266 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 267 | ................. | 268 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 269 | GROUP RECORDS (N) | 270 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 272 where each group record is of the form: 274 +-+-+-+-+-+-+-+-+ 275 | RESERVED | (1 byte) 276 +-+-+-+-+-+-+-+-+ 277 | Num of Sources| (1 byte) 278 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 279 | Group Address (6 bytes) | 280 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 281 | Source 1 Address (6 bytes) | 282 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 283 | Source 2 Address (6 bytes) | 284 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 285 | Source M Address (6 bytes) | 286 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 288 o Type: sub-TLV Type, set to 1 (GMAC-ADDR) of length 1 byte. 290 o Length: Total number of bytes contained in the value field. 292 o Topology-Id/Nickname : Depending on the technology in which it is 293 used, this carries the topology-id or nickname. When this field 294 is set to zero this implies that the MAC addresses are reachable 295 across all topologies or across all nicknames of the originating 296 IS. 298 o Confidence: This carries an 8-bit quantity indicating the 299 confidence level in the MAC addresses being transported. Whether 300 this field is used, and its semantics if used, are further defined 301 by the specific protocol using Layer-2-IS-IS. If not used, it 302 MUST be set to zero on transmission and be ignored on receipt. 304 o RESERVED: Must be sent as zero on transmission and is ignored on 305 receipt. 307 o VLAN-ID: This carries a 12-bit VLAN identifier that is valid for 308 all subsequent MAC addresses in this sub-TLV, or the value zero if 309 no VLAN is specified. 311 o Number of Group Records: This is of length 1 byte and lists the 312 number of group records in this sub-TLV. 314 o Group Record: Each group record has a one byte reserved space and 315 the next byte carries the number of sources. It then has a 48-bit 316 multicast Group Address followed by 48-bit source MAC addresses. 317 An address being a group multicast address or unicast source 318 address can be checked using the multicast bit in the address. If 319 the number of sources do not fit in a single sub-TLV, it is 320 permitted to have the same group address repeated with different 321 source addresses in another sub-TLV of another instance of the 322 Group Address TLV. 324 The GMAC-ADDR sub-TLV is carried only within a GADDR TLV and MUST be 325 carried in a standard Level 1 link state MGROUP PDU. 327 2.2.2. The Group IP Address sub-TLV 329 The Group IP Address (GIP-ADDR) sub-TLV IS-IS sub-TLV type 2 within 330 the GADDR TLV and has the following format: 332 +-+-+-+-+-+-+-+-+ 333 | Type=GIP-ADDR | 334 +-+-+-+-+-+-+-+-+ 335 | Length | (1 byte) 336 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 337 | Topology-Id/ Nickname | (2 bytes) 338 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 339 | Confidence | (1 byte) 340 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 341 | RESV | VLAN-ID | (2 bytes) 342 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 343 |Num Group Recs | (1 byte) 344 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 345 | GROUP RECORDS (1) | 346 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 347 | ................. | 348 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 349 | GROUP RECORDS (N) | 350 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 352 where each group record is of the form: 354 +-+-+-+-+-+-+-+-+ 355 | RESERVED | (1 byte) 356 +-+-+-+-+-+-+-+-+ 357 | Num of Sources| (1 byte) 358 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 359 | Group Address (4 bytes) | 360 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 361 | Source 1 Address (4 bytes) | 362 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 363 | Source 2 Address (4 bytes) | 364 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 365 | Source M Address (4 bytes) | 366 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 368 o Type: sub-TLV Type, set to 2 (GIP-ADDR). 370 o Length: Total number of bytes contained in the value field of the 371 sub-TLV. 373 o Topology-Id/Nickname : Depending on the technology in which it is 374 used, this carries the topology-id or nickname. When this field 375 is set to zero this implies that the addresses are reachable 376 across all topologies or across all nicknames of the originating 377 IS. 379 o Confidence: This carries an 8-bit quantity indicating the 380 confidence level in the IP addresses being transported. Whether 381 this field is used, and its semantics if used, are further defined 382 by the specific protocol using Layer-2-IS-IS. If not used, it 383 must be set to zero on transmission and be ignored on receipt. 385 o RESERVED: Must be sent as zero on transmission and is ignored on 386 receipt. 388 o VLAN-ID: This carries a 12-bit VLAN identifier that is valid for 389 all subsequent addresses in this sub-TLV, or the value zero if no 390 VLAN is specified. 392 o Number of Group Records: This is of length 1 byte and lists the 393 number of group records in this sub-TLV. 395 o Group Record: Each group record has a one byte reserved space and 396 the next byte carries the number of sources. It is followed by a 397 32-bit IPv4 Group Address followed by 32-bit source IPv4 398 addresses. If the number of sources do not fit in a single sub- 399 TLV, it is permitted to have the same group address repeated with 400 different source addresses repeated in another sub-TLV of another 401 instance of the Group Address TLV. 403 The GIP-ADDR sub-TLV is carried only within a GADDR TLV and MUST be 404 carried in a standard Level 1 link state MGROUP PDU. 406 2.2.3. The Group IPv6 Address sub-TLV 408 The Group IPv6 Address (GIPV6-ADDR) sub-TLV is IS-IS sub-TLV type 3 409 and has the following format: 411 +-+-+-+-+-+-+-+-+ 412 |Type=GIPv6-ADDR| 413 +-+-+-+-+-+-+-+-+ 414 | Length | (1 byte) 415 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 416 | Topology-Id/ Nickname | (2 bytes) 417 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 418 | Confidence | (1 byte) 419 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 420 | RESV | VLAN-ID | (2 bytes) 421 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 422 |Num Group Recs | (1 byte) 423 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 424 | GROUP RECORDS (1) | 425 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 426 | ................. | 427 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 428 | GROUP RECORDS (N) | 429 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 431 where each group record is of the form: 433 +-+-+-+-+-+-+-+-+ 434 | RESERVED | (1 byte) 435 +-+-+-+-+-+-+-+-+ 436 | Num of Sources| (1 byte) 437 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 438 | Group Address (16 bytes) | 439 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 440 | Source 1 Address (16 bytes) | 441 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 442 | Source 2 Address (16 bytes) | 443 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 444 | Source M Address (16 bytes) | 445 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 447 o Type: sub-TLV Type, set to 3 (GIPV6-ADDR). 449 o Length: Total number of bytes contained in the value field. 451 o Confidence: This carries an 8-bit quantity indicating the 452 confidence level in the IPv6 addresses being transported. Whether 453 this field is used, and its semantics if used, are further defined 454 by the specific protocol using Layer-2-IS-IS. If not used, it 455 must be set to zero on transmission and be ignored on receipt. 457 o Topology-Id/Nickname : Depending on the technology in which it is 458 used, this carries the topology-id or nickname. When this field 459 is set to zero this implies that the addresses are reachable 460 across all topologies or across all nicknames of the originating 461 IS. 463 o RESERVED: Must be sent as zero on transmission and is ignored on 464 receipt. 466 o VLAN-ID: This carries a 12-bit VLAN identifier that is valid for 467 all subsequent addresses in this sub-TLV, or the value zero if no 468 VLAN is specified. 470 o Number of Group Records: This of length 1 byte and lists the 471 number of group records in this sub-TLV. 473 o Group Record: Each group record has a one byte reserved space and 474 the next byte carries the number of sources. It is followed by a 475 128-bit multicast IPv6 Group Address followed by 128-bit source 476 IPv6 addresses. If the number of sources do not fit in a single 477 sub-TLV, it is permitted to have the same group address repeated 478 with different source addresses repeated in another sub-TLV in 479 another instance of the Group Address TLV. 481 The GIPV6-ADDR sub-TLV is carried only within a GADDR TLV and MUST be 482 carried in a standard Level 1 link state MGROUP PDU. 484 2.2.4. The SPBV MAC Address sub-TLV 486 The SPBV MAC Address (SPBV-MAC-ADDR) sub-TLV is IS-IS sub-TLV type 4 487 and has the following format: 489 +-+-+-+-+-+-+-+-+ 490 | Type=SPBV-ADDR| (1 byte) 491 +-+-+-+-+-+-+-+-+ 492 | Length | (1 byte) 493 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 494 |R|R|S|R| SPVID | (2 bytes) 495 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 496 |T|R| Reserved | MAC 1 Address | (1+6 bytes) 497 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 498 | ... | 499 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 500 |T|R| Reserved | MAC N Address | (1+6 bytes) 501 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 503 o Type: sub-TLV Type, set to 4 (SPBV-MAC-ADDR). 505 o Length: Total number of bytes contained in the value field. The 506 number of MAC address associated with the SPVID is computed by 507 (Length - 2)/7. 509 o SR bits (2-bits) The SR bits are the service requirement parameter 510 from MMRP. The service requirement parameters have the value 0 511 (Forward all Groups) and 1 (Forward All Unregistered Groups) 512 defined. However this attribute may also be missing. So the SR 513 bits are defined as 0 not declared, 1 Forward all Groups and 2 514 Forward All Unregistered Groups. These bits have two Reserved 515 bits set before them. 517 o SPVID (12-bits) The SPVID and by association Base VID and the ECT- 518 ALGORITHM and SPT Set that the MAC addresses defined below will 519 use. If the SPVID is not allocated the SPVID Value is 0. Note 520 that if the ECT-Algorithm in use is Spanning Tree Algorithm this 521 value should be populated with the Base VID and the MAC can be 522 populated. 524 o T Bit (1-bit) This is the Transmit allowed Bit for the following 525 group MAC address. This is an indication that SPBV Group MAC 526 Address with SPVID of source should be populated (for the bridge 527 advertising this Group MAC), and installed in the FDB of transit 528 bridges, when the bridge computing the trees is on the 529 corresponding ECT-ALGORITHM shortest path between the bridge 530 advertising this MAC with the T bit set, and any receiver of this 531 Group MAC Address. A bridge that does not advertise this bit set 532 for an Group MAC Address should have no forwarding state installed 533 for traffic originating from that bridge on other transit bridges 534 in the network. 536 o R Bit (1-bit) This is the Receive allowed Bit for the following 537 Group MAC Address. This is an indication that SPBV Group MAC 538 Addresses as receiver should be populated (for bridges advertising 539 this Group MAC Address with the T bit set) and installed when the 540 bridge computing the trees lies on the corresponding shortest path 541 for this ECT-ALGORITHM between this receiver and any transmitter 542 on this Group MAC Address. An entry that does not have this bit 543 set for a Group MAC Address is prevented from receiving on this 544 Group MAC Address because transit bridges will not install 545 multicast forwarding state towards it in their FDBs or the traffic 546 is explicitly filtered. 548 o MAC Address (48-bits) The MAC is address is either a group address 549 or an individual address. Individual addresses are optional and 550 normal MAC learning can be used. When the MAC address is a group 551 address it declares this bridge as part of the multicast interest 552 for this destination MAC address. Multicast trees can be 553 efficiently constructed for destination by populating multicast 554 FDB entries for the subset of the shortest path tree that connects 555 the bridges supporting the multicast address. This replaces the 556 function of MMRP for SPTs. The T and R bits above have meaning if 557 this is a group address. Individual addresses are populated only 558 as if the R bit was not set. 560 The SPBV-MAC-ADDR sub-TLV is carried within the GADDR TLV and MUST be 561 carried only in a standard Level 1 link state MGROUP PDU. 563 2.3. Multi Topology aware Port Capability TLV 565 The Multi Topology aware Port Capability (MT-PORT-CAP) is an IS-IS 566 TLV type 143 [TBD], and has the following format: 567 0 1 2 3 568 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 1 569 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 570 |Type=MT PORTCAP| Length |O|R|R|R| Topology Identifier | 571 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 572 | sub-TLVs | 573 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 575 o Type: TLV Type, set to MT-PORT-CAP TLV 143 [TBD]. 577 o Length: Total number of bytes contained in the value field, 578 including the length of the sub-TLVs carried in this TLV. 580 o O bit: The overload bit that follows the semantics associated with 581 an overloaded intermediate system. 583 o Topology Identifier: MT ID is a 12-bit field containing the MT ID 584 of the topology being announced. This field when set to zero 585 implies that it is being used to carry base topology information. 586 In TRILL this value is set to ZERO, however, in IEEE SPB and SPBB, 587 it may be non-zero. 589 o sub-TLVs: The MT aware Port Capabilities TLV value contains sub- 590 TLVs formatted as described in [RFC5305]. They are defined in the 591 next sections. 593 The MT-PORT-CAP TLV may occur multiple times, and is carried only 594 within a Hello PDU. 596 2.3.1. The Special VLANs and Flags sub-TLV 598 The Special VLANs and Flags (VLAN and Flags) sub-TLV MUST only appear 599 in a MT-PORT-CAP TLV. It is carried exactly once in every TRILL IIH 600 PDU. It has the following format: 602 +-+-+-+-+-+-+-+-+ 603 |Type=VLAN Flags| (1 byte) 604 +-+-+-+-+-+-+-+-+ 605 | Length | (1 byte) 606 +--------------------------------+ 607 | Port ID | (2 bytes) 608 +--------------------------------+ 609 | Sender Nickname | (2 bytes) 610 +--+--+--+--+--------------------+ 611 |AF|AC|VM|BY| Outer.VLAN | (2 bytes) 612 +-----------+--------------------+ 613 |Reserved | Desig.VLAN | (2 bytes) 614 +-----------+--------------------+ 616 o Type: sub-TLV Type, set to VLAN and Flags sub-TLV 1 [TBD]. 618 o Length: 8 - Number of bytes contained in the value field. 620 o Port ID: An ID for the port on which the enclosing TRILL IIH PDU 621 is being sent. The transmitting RBridge assigns this ID such that 622 each of its ports has an ID different from all of its other ports. 624 o Sender nickname: If the sending intermediate system is holding any 625 nicknames, one MUST be included here. Otherwise, the field is set 626 to zero. This field is to support intelligent end stations that 627 determine the egress RBridge for unicast data through a directory 628 service or the like and need a nickname for their first hop to 629 insert as the ingress nickname to correctly format a TRILL 630 encapsulated data frame. 632 o The fifth and sixth bytes have a copy of the Outer VLAN ID 633 associated with the Hello frame when it was sent. The lower 4 634 bits of the fifth byte give the upper ID bits of the VLAN ID and 635 the sixth byte gives the lower VLAN ID bits. 637 o The upper 4 bits of the fifth byte are flag bits as shown. The AF 638 bit, if one, indicates that the sending Intermediate System 639 believes it is Appointed Forwarder for the VLAN and port on which 640 the Hello was sent. The AC bit, if one, indicates that the 641 sending port is configured as an access port. The VM bit, if a 642 one, indicates that the sending Intermediate System has detected 643 VLAN mapping within the link. The BY bit, if set, indicates 644 bypass psuedonode. 646 o The seventh and eighth bytes give the Designated VLAN for the 647 link. The lower 4 bits of the seventh byte give the upper ID bits 648 of the Designated VLAN and the eighth byte gives the lower VLAN ID 649 bits. The upper 4 bits of the seventh byte are reserved and MUST 650 be sent as zero and ignored on receipt. 652 The VLAN and Flags sub-TLV is carried within the MT-PORT-CAP TLV. It 653 MUST be carried exactly once in a TRILL IIH PDU. It MUST NOT be 654 carried within a LAN or a P2P IIH PDU. 656 2.3.2. Enabled VLANs sub-TLV 658 The Enabled VLAN sub-TLV specifies the VLANs enabled for end station 659 service at the port on which the Hello was sent. It has the 660 following format: 662 +-+-+-+-+-+-+-+-+ 663 |Type=EnabledVLAN| 664 +-+-+-+-+-+-+-+-+ 665 | Length | (1 byte) 666 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 667 |Resv | Start Vlan Id | (2 bytes) 668 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 669 | Vlan bit-map.... 670 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 672 o Type: sub-TLV Type, set to Enabled VLANs sub-TLV 2 [TBD]. 674 o Length: variable, depending on contents described next. 676 o The minimum size of the value is 3 bytes. The third and 677 subsequent bytes provide a bit map of enabled VLANs starting at 678 the VLAN ID indicated in the first two bytes. The lower order 679 four bits of the first byte give the upper bits of the starting 680 VLAN ID and the second byte gives the lower bits of that VLAN ID. 681 The upper four bits of the first byte are reserved and MUST be 682 sent as zero and ignored on receipt. The highest order bit of the 683 third byte indicates the VLAN equal to the starting ID while the 684 lowest order bit of the third byte indicates that ID plus 7. For 685 example, VLANs 1 and 14 being enabled for end station service 686 could be encoded in 4-bytes value 0x00 0x01 0x80 0x04 or, 687 alternatively, as 0x00 0x00 0x40 0x02. 689 This sub-TLV may occur more than once in a Hello and a VLAN is 690 enabled for end station service on the port where the Hello was sent 691 if this is indicated by any occurrence in the Hello. For example, a 692 receiver could allocate a 512-byte buffer and, with appropriate 693 shifting operations, OR in the enabled bits for each sub-TLV of this 694 type it finds in a Hello to derive the complete bit map of these 695 VLANs. 697 The Enabled VLAN sub-TLV is carried only within the MT-PORT-CAP TLV. 699 If present, it MUST be carried in TRILL IIH PDU. It MUST NOT be 700 carried within a LAN IIH or a P2P IIH PDU. 702 2.3.3. Appointed Forwarders sub-TLV 704 The Appointed Forwarder sub-TLV provides the mechanism by which the 705 Designated Intermediate System can inform other Intermediate Systems 706 on the link that they are the designated VLAN-x forwarder for that 707 link for one or more ranges of VLAN IDs. It has the following 708 format: 710 +-+-+-+-+-+-+-+-+ 711 |Type=App Frwrdr| 712 +-+-+-+-+-+-+-+-+ 713 | Length | (1 byte) 714 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 715 | Appointment Information (1) | (6 bytes) 716 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 717 | ................. | 718 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 719 | Appointment Information (N) | (6 bytes) 720 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 722 where each appointment information is of the form: 724 +---------------------------+ 725 | Appointee Nick | (2 bytes) 726 +---------------------------+ 727 | Res | Start VLAN ID | (2 bytes) 728 +---------------------------+ 729 | Res | End VLAN ID | (2 bytes) 730 +---------------------------+ 732 o Type: sub-TLV Type, set to Appointed Forwarders sub-TLV 3 [TBD]. 734 o Length: The size of the value is 6*n bytes where there are n 735 appointments. 737 o The appointed forwarder Intermediate System is specified by its 738 nickname in the first two bytes. 740 o The "Res" fields of 4 bits each are reserved and MUST be sent as 741 zero and ignored on receipt. 743 The VLAN range given is inclusive. To specify a single VLAN, that 744 VLAN ID appears as both the start and end VLAN. The Intermediate 745 System whose nickname is given is appointed forwarder for those VLANs 746 for which it has end station service enabled (see item 2 above) in 747 the inclusive range. For example, assume an Intermediate System with 748 end station service enabled on VLANs 100, 101, 199, and 200 (and 749 possibly other VLANs less than 100 or greater than 200), but not 750 enabled for VLANs 102 through 198. It could be appointed forwarder 751 for these four VLANs through either (1) a single 6-byte value 752 sequence with start and end VLAN IDs of 100 and 200, or (2) a 12-byte 753 value sequence with start and end VLAN IDs of 100 and 101 in the 754 first part and 199 and 200 in the second part. 756 An Intermediate System's nickname may occur as appointed forwarder 757 for multiple VLAN ranges within the same or different Port Capability 758 TLVs within a TRILL Hello. In the absence of appointed forwarder 759 sub-TLVs referring to a VLAN, the Designated Intermediate System acts 760 as the appointed forwarder for that VLAN if end station service is 761 enabled. 763 The Appointed Forwarder sub-TLV is carried within the MT-PORT-CAP 764 TLV. If present, it MUST be carried in a TRILL IIH PDU. This MUST 765 NOT be carried in a LAN IIH PDU or a P2P IIH PDU. 767 2.3.4. Hop-by-Hop Options (HBHOPT) sub-TLV 769 By including this sub-TLV within one or more MT aware Port Capability 770 TLVs in its Hellos, an Intermediate System can advertise the Hop-by- 771 Hop options it supports on the port through which it sends the Hello. 772 This sub-TLV may appear zero or more times within a MT aware Port 773 Capability TLV. By default, in the absence of any HBHOPT sub-TLVs, 774 no Hop-by-Hop options are supported. 776 There are two types of Hop-by-Hop option encodings within the TRILL 777 Header: bit options and TLV encoded options. 779 The bit-encoded options supported are indicated by an HBHOPT sub-TLV 780 of length 3: an initial value byte of 0x00 followed by two bytes in 781 which each bit indicates that the corresponding bit option is 782 implemented; in those two bytes the top two bits (0xC000) are 783 critical option summary bits that all RBridges MUST understand; 784 therefore support for these bits need not be advertised. Those two 785 bits are reserved in the HBHOPT sub-TLV and must be sent as zero and 786 are ignored on receipt. 788 The implementation of the type of option encoded in a TRILL Header as 789 a TLV is indicated by an HBHOPT sub-TLV whose value starts with a 790 byte equal to the first byte of the option. Such HBHOPT sub-TLVs may 791 have additional value bytes further indicating how the option is 792 supported as specified with the option's definition, for example a 793 list of supported security algorithms. 795 +-+-+-+-+-+-+-+-+ 796 | Type = HBHOPT | 797 +-+-+-+-+-+-+-+-+ 798 | Length | (1 byte) 799 +-+-+-+-+-+-+-+-+ 800 | Option | (1 byte) 801 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 802 | Option dependent variable length information | 803 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 805 o Type: sub-TLV Type, set to Hop-by-Hop sub-TLV 4 [TBD]. 807 o Length: variable, minimum 1. 809 o Value: Either 0x00 followed by implementation information for bit 810 encoded options or a non-zero option type byte followed by option 811 dependent information for that option. 813 2.3.5. Base VLAN-Identifiers sub-TLV 815 This sub-TLV is added to an IIH PDU to indicate the algorithms for 816 the VIDs and the Base VIDs and VIDs or Backbone-VIDs (B-VIDs) that 817 are in use. This information should be the same on all bridges in 818 the topology identified by MT-PORT-CAP TLV it is being carried. 819 Discrepancies between neighbours with respect to this sub-TLV are 820 temporarily allowed but the Base-VID must agree and use a spanning 821 tree algorithm. 823 +-+-+-+-+-+-+-+-+ 824 |Type = B-VID | 825 +-+-+-+-+-+-+-+-+ 826 | Length | (1 byte) 827 +-+-+-+-+-+-+-+-+-------------------------------- 828 | ECT - VID Tuple (1) (6 bytes) | 829 +-----------------------------------------------+ 830 | ......................... | 831 +-----------------------------------------------+ 832 | ECT - VID Tuples (N) (6 bytes) | 833 +-----------------------------------------------+ 835 o Type: sub-TLV Type, set to Base-VLAN-ID sub-TLV 5 [TBD]. 837 o Length: The size of the value is ECT-VID Tuples*6 bytes. Each 838 6-byte part of the ECT-VID tuple is formatted as follows: 840 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 841 | ECT - Algorithm (32 bits) | 842 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 843 | Base VID (12 bits) |U|M|RES| 844 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 846 o ECT-ALGORITHM (4 bytes) The ECT-ALGORITHM is advertised when the 847 bridge supports a given ECT-ALGORITHM (by OUI/Index) on a given 848 Base VID 850 o Base VID (12-bits) The Base-VID that is associated with the SPT 851 Set. 853 o Use-Flag (1-bit) The Use-flag is set if this bridge, or any bridge 854 that this bridge sees is currently using this ECTALGORITHM and 855 Base VID. 857 o M-Bit (1-bit) The M-bit indicates if this is SPBM or SPBV mode. 859 The Base VLAN-Identifier sub-TLV is carried within the MT-PORT-CAP 860 TLV and this is carried in a IIH PDU. 862 2.3.6. SPB Digest sub-TLV 864 This sub-TLV is added to an IIH PDU to indicate the digest for 865 Multiple spanning tree configuration Digests (MCID) and the IS-IS 866 agreement Digest. This information should be the same on all bridges 867 in the topology identified by MT-PORT-CAP TLV it is being carried. 868 These digests indicate when the configuration and the topology are 869 synchronized and are used to control the updating of forwarding 870 information. The MCID is controlled solely by configuration and is a 871 digest of the allocated VIDs to various protocols. Two MCIDs are 872 carried to allow transitions when the configuration changes are non- 873 critical. During the propagation of LSPs the agreement digest will 874 vary between neighbors until the LSPs are common. During that period 875 switches or bridges running SPB will not allow multicast forwarding 876 between neighbors that have differing digests. Discrepancies between 877 neighbors with respect to this sub-TLV are temporarily allowed but 878 the Base-VID must agree and use a spanning tree algorithm. 880 +-+-+-+-+-+-+-+-+ 881 |Type =SPBDigest| 882 +-+-+-+-+-+-+-+-+ 883 | Length | (1 byte) 884 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 885 | MCID (50 Bytes) | 886 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 887 | Aux MCID (50 Bytes) | 888 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 889 | Agreement Digest (32 Bytes) | 890 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 891 |RES | A | D| 892 +-+-+-+-+-+-+-+-+ 894 o Type: sub-TLV Type, set to SPB Digest sub-TLV 6 [TBD]. 896 o Length: The size of the value defined below. 898 o MCID (50-bytes) The complete MCID defined in IEEE 802.1Q which 899 identifies an SPT Region. 901 o Aux MCID (50-bytes) The complete MCID defined in IEEE 802.1Q which 902 identifies an SPT Region. The aux MCID allows SP Regions to be 903 migrated allocating new VLAN to FID Mappings. 905 o Agreement Digest (32-bytes) This digest is use to determine when 906 IS-IS is synchronized between neighbors. 908 o A (2 bits) The agreement number 0-3 which aligns with BPDUs 909 agreement number concept. When the Agreement Digest for this node 910 changes this number is updated and sent in the hello. 912 o D (2 bits) The discarded agreement number 0-3 which aligns with 913 BPDUs agreement number concept. When the Agreement Digest for 914 this node changes this number is updated. Once an Agreement has 915 been sent it is considered outstanding until a matching or more 916 recent Discarded Agreement Number is received. 918 The SPB Digest sub-TLV is carried within the MT-PORT-CAP TLV and this 919 is carried in a IIH PDU. 921 2.3.7. Site Identifier sub-TLV 923 The site identifier sub-TLV carries information about the site this 924 device belongs to. This is used in OTV [OTV] to aid in Authoritative 925 Edge Device election. It has the following format: 927 +-+-+-+-+-+-+-+-+ 928 |Type = SiteCap | 929 +-+-+-+-+-+-+-+-+ 930 | Length | (1 byte) 931 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 932 | System ID (6 bytes) | 933 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 934 | Cluster ID (2 bytes) | 935 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 936 |Resv (7bits) |U| (1 byte) 937 +-+-+-+-+-+-+-+-+ 939 o Type: sub-TLV Type, set to Site Identifier sub-TLV 250 [TBD]. 941 o Length: The size of the value. 943 o System Id: The system-id of the site. 945 o Cluster Id: The cluster-id within the site. 947 o Reserved: Must be sent as zero on transmission and is ignored on 948 receipt. 950 o U bit: Denotes if the site is a unicast only site. 952 The Site Capability sub-TLV is carried only within the MT-PORT-CAP 953 TLV and this is carried in a Hello PDU. There must be only one 954 occurrence of this sub-TLV in the Hello PDU. 956 2.3.8. Site Group IPv4 sub-TLV 958 The Site Group IPv4 sub-TLV carries information about the overlays 959 active on this device. This is used in OTV [OTV] to aid in 960 Authoritative Edge Device election. It has the following format: 962 +-+-+-+-+-+-+-+-+ 963 |Type=SiteGrpIP | 964 +-+-+-+-+-+-+-+-+ 965 | Length | (1 byte) 966 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 967 | IPv4 address (4 bytes) | 968 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 969 | .................. | 970 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 971 | IPv4 address (4 bytes) | 972 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 974 o Type: sub-TLV Type, set to Site Group IP sub-TLV 251 [TBD]. 976 o Length: The size of the value. 978 o Value: The list of IPv4 addresses used by the site. 980 The Site Group IPv4 sub-TLV is carried within the MT-PORT-CAP TLV and 981 this is carried in a Hello PDU. There may be more than one 982 occurrence of this sub-TLV in the Hello PDU. 984 2.3.9. Site Group IPv6 sub-TLV 986 The Site Group IPv6 sub-TLV carries information about the overlays 987 active on this device. This is used in OTV [OTV] to aid in 988 Authoritative Edge Device election. It has the following format: 990 +-+-+-+-+-+-+-+-+ 991 |Type=SiteGrpIPv6| 992 +-+-+-+-+-+-+-+-+ 993 | Length | (1 byte) 994 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 995 | IPv6 address (16 bytes) | 996 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 997 | .................. | 998 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 999 | IPv6 address (16 bytes) | 1000 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1002 o Type: sub-TLV Type, set to Site Group IPv6 sub-TLV 252 [TBD]. 1004 o Length: The size of the value. 1006 o Value: The list of IPv6 addresses used by the site. 1008 The Site Group IPv6 sub-TLV is carried within the MT-PORT-CAP TLV and 1009 this is carried in a Hello PDU. There may be more than one 1010 occurrence of this sub-TLV in the Hello PDU. 1012 2.3.10. Adjacency Server IPv4 sub-TLV 1014 The Adjacency Server IPv4 sub-TLV carries information about the 1015 capability of the sites in OTV [OTV]. It has the following format: 1017 +-+-+-+-+-+-+-+-+ 1018 |Type = ASIPv4 | 1019 +-+-+-+-+-+-+-+-+ 1020 | Length | (1 byte) 1021 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1022 | Adjacency IPv4 Information (1) | (5 bytes) 1023 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1024 | ................. | 1025 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1026 | Adjacency IPv4 Information (N) | (5 bytes) 1027 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1029 where each adjacency IPv4 information is of the form: 1031 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1032 | IPv4 address (4 bytes) | 1033 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1034 |Resv (7bits) |U| (1 byte) 1035 +-+-+-+-+-+-+-+-+ 1037 o Type: sub-TLV Type, set to Adjacency Server IP sub-TLV 253 [TBD]. 1039 o Length: The size of the value, 5*n, where there are n adjacency 1040 server information blocks. 1042 o IPv4 Address: The IPv4 addresses used by the sites. 1044 o Reserved: Must be sent as zero on transmission and is ignored on 1045 receipt. 1047 o U bit: Denotes if the site is a unicast only site. 1049 The Adjacency Server IPv4 sub-TLV is carried within the MT-PORT-CAP 1050 TLV and this is carried in a Hello PDU. 1052 2.3.11. Adjacency Server IPv6 sub-TLV 1054 The Adjacency Server IPv6 sub-TLV carries information about the 1055 capability of the sites in OTV [OTV]. It has the following format: 1057 +-+-+-+-+-+-+-+-+ 1058 |Type = ASIPv6 | 1059 +-+-+-+-+-+-+-+-+ 1060 | Length | (1 byte) 1061 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1062 | Adjacency IPv6 Information (1) | (17 bytes) 1063 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1064 | ................. | 1065 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1066 | Adjacency IPv6 Information (N) | (17 bytes) 1067 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1069 where each adjacency IPv6 information is of the form: 1071 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1072 | IPv6 address (16 bytes) | 1073 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1074 |Resv (7bits) |U| (1 byte) 1075 +-+-+-+-+-+-+-+-+ 1077 o Type: sub-TLV Type, set to Adjacency Server IPv6 sub-TLV 254 1078 [TBD]. 1080 o Length: The size of the value. 1082 o Value: The IPv6 addresses used by the sites. 1084 o Reserved: Must be sent as zero on transmission and is ignored on 1085 receipt. 1087 o U bit: Denotes if the site is a unicast only site. 1089 The Adjacency Server IPv6 sub-TLV is carried within the MT-PORT-CAP 1090 TLV and this is carried in a Hello PDU. Multiple such TLVs may be 1091 carried in a IIH PDU. 1093 2.4. Sub-TLVs for the Router Capability TLV 1095 The Router Capability TLV is an optional TLV [RFC 4971] that may be 1096 generated by the originating Intermediate System. We specify these 1097 additional sub-TLVs that can be carried in it. These sub-TLVs 1098 announce the capabilities of the Intermediate System to the entire 1099 IS-IS routing domain. 1101 2.4.1. The TRILL Version sub-TLV 1103 The TRILL Version (TRILL-VER) sub-TLV indicates support of TRILL 1104 Versions. The device announces the maximum version of TRILL, it is 1105 capable of supporting, including lower versions. In the event, this 1106 sub-TLV is missing, this implies that the node can only support the 1107 base version of the protocol. 1108 0 1 2 3 1109 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 1110 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1111 | Type | Length | Reserved | Max-version | 1112 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1114 o Type: sub-TLV Type, set to 5 (TRILL-VER). 1116 o Length: 2 - Total number of bytes contained in the value. 1118 o Reserved: Set to zero on transmission and ignored on receipt. 1120 o Max-version: Set to application dependent values. 1122 2.4.2. The Nickname sub-TLV 1124 The Nickname (NICKNAME) sub-TLV carries information about the 1125 nicknames of the advertising device, along with information about its 1126 priority to hold those nicknames. The Nickname sub-TLV MUST be 1127 carried within a Router CAPABILITY TLV in a level-1 LSP generated by 1128 the originating IS. Multiple instances of this sub-TLV are allowed 1129 to be carried. 1131 +-+-+-+-+-+-+-+-+ 1132 |Type = NICKNAME| 1133 +-+-+-+-+-+-+-+-+ 1134 | Length | (1 byte) 1135 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1136 | NICKNAME RECORDS (1) | 1137 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1138 | ................. | 1139 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1140 | NICKNAME RECORDS (N) | 1141 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1143 where each nickname record is of the form: 1145 +-+-+-+-+-+-+-+-+-+ 1146 |Nickname Priority| (1 byte) 1147 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1148 | Tree Root Priority | (2 byte) 1149 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1150 | Nickname | (2 bytes) 1151 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1152 o Type: sub-TLV Type, set to 6 (NICKNAME). 1154 o Length: 5*N, where N is the number of nickname records present. 1156 o Nickname Priority: This is an unsigned 8-bit integer that gives 1157 the priority with which this node holds this nickname. 1159 o Tree Root Priority: This is an unsigned 16-bit integer that gives 1160 the priority of this nickname to become a distribution tree root. 1162 o Nickname: This is an unsigned 16-bit integer that gives device 1163 identifier or alias. 1165 Each nickname record consists of a one-byte priority set to 1166 application dependent values, two bytes of tree root priority and two 1167 bytes of device identifier or alias (i.e., actual nickname). 1169 2.4.3. The Trees sub-TLV 1171 The Trees sub-TLV MUST occur only once and is carried within the 1172 Router CAPABILITY TLV in a level-1 non-pseudo-node LSP generated by 1173 the originating IS. Each device announces three numbers: the number 1174 of trees it dictates that all other Intermediate Systems in the 1175 campus compute if it is the highest priority tree root; the maximum 1176 number of trees it is able to compute; and the number of distribution 1177 trees it wishes to be able to use in forwarding multi-destination 1178 traffic. 1180 All nodes run the same algorithm as described in [RBRIDGES] and the 1181 elected highest priority tree root dictates the number of 1182 distribution tree roots to be used in the network domain and can 1183 additionally list those roots in the tree roots identifier sub-TLV. 1185 +-+-+-+-+-+-+-+-+ 1186 |Type = TREE | 1187 +-+-+-+-+-+-+-+-+ 1188 | Length | (1 byte) 1189 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1190 | Number of trees to compute | (2 byte) 1191 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1192 | Maximum trees able to compute | (2 byte) 1193 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1194 | Number of trees to use | (2 byte) 1195 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1197 o Type: sub-TLV Type, set to 7 (TREE). 1199 o Length: 6 : Total number of bytes contained in the value field. 1201 o Number of trees to compute: This is an unsigned 16-bit integer 1202 that gives the requested number of distribution trees for multi- 1203 destination frames that will be in use in the Layer-2 domain, if 1204 this device becomes the highest priority tree root in the domain. 1206 o Maximum number of trees able to compute: This is an unsigned 16- 1207 bit integer that give the maximum number of threes that the 1208 originating IS is able to compute for the campus. 1210 o Number of trees to use: This is an unsigned 16-bit integer that 1211 gives the number of distribution trees the originating IS wishes 1212 to use. 1214 2.4.4. The Tree Identifiers Sub-TLV 1216 The tree identifiers sub-TLV is an ordered list of nicknames. When 1217 originated by the Intermediate System which is the highest priority 1218 tree root, this list is the trees which the other Intermediate 1219 Systems are required to compute. If this information is spread 1220 across multiple sub-TLVs, the starting tree number is used to to 1221 allow the ordered lists to be correctly concatenated. It is carried 1222 within the Router CAPABILITY TLV in a level-1 non-pseudo-node LSP and 1223 is given as: 1225 +-+-+-+-+-+-+-+-+ 1226 |Type=TREE-RT-ID| 1227 +-+-+-+-+-+-+-+-+ 1228 | Length | (1 byte) 1229 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1230 |Starting Tree Number | (2 bytes) 1231 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1232 | Nickname (K-th root) | (2 bytes) 1233 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1234 | Nickname (K+1 - th root) | (2 bytes) 1235 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1236 | Nickname (...) | 1237 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1239 o Type: sub-TLV Type, set to 8 (TREE-RT-IDs). 1241 o Length: Total number of bytes contained in the value field. 1243 o Starting Tree Number: This identifies the starting tree number of 1244 the nicknames that are trees for the domain. This is set to 1 for 1245 the first sub-TLV. Subsequent sub-TLVs will have the starting 1246 number of the ordered list. In the event a tree identifier can be 1247 computed from two such sub-TLVs and are different, then it is 1248 assumed that this is a transient condition that will get cleared. 1249 During this transient time, such trees cannot be computed. 1251 o Nickname: The nickname on which this tree is based. 1253 2.4.5. The Trees Used Identifiers Sub-TLV 1255 This sub-TLV has the same structure as the Tree Identifiers sub-TLV 1256 specified in the above section. The only difference is that its sub- 1257 TLV type is set to 9 TBD (TREE-USE-IDs) and the trees listed are only 1258 those that the originating intermediate systems wishes to use. 1260 2.4.6. Interested VLANs and Spanning Tree Roots sub-TLV 1262 The value of this sub-TLV consists of a VLAN range, flags, and a 1263 variable length list of spanning tree root bridge IDs. This sub-TLV 1264 may appear zero, one, or many times. The union of the VLAN ranges in 1265 all occurrences MUST be precisely the set of VLANs for which the 1266 originating Intermediate System is appointed forwarder on at least 1267 one port and the VLAN ranges in multiple VLANs sub-TLVs for an 1268 Intermediate System MUST NOT overlap. That is, the intersection of 1269 the VLAN ranges for any pair of these sub-TLVs originated by an 1270 Intermediate System must be null. The value length is 10 + 6*n where 1271 n is the number of root bridge IDs. The TLV layout is as follows: 1273 +-+-+-+-+-+-+-+-+ 1274 |Type = INT-VLAN| 1275 +-+-+-+-+-+-+-+-+ 1276 | Length | (1 byte) 1277 +---------------+-----+ 1278 | Nickname | (2 bytes) 1279 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1280 | Interested VLANS | (8 bytes) 1281 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1282 | Root Bridges | (6*n bytes) 1283 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1285 o Type: sub-TLV Type, set to 10 (INT-VLAN). 1287 o Length: Total number of bytes contained in the value field. 1289 o Nickname: If this is set to 0, then it applies to all nicknames 1290 generated by the node. It may alternatively be set to a specific 1291 nickname, in the event a node wants to segregate traffic using 1292 multiple nicknames. 1294 o Interested VLANS: In the Interested VLANs, as shown below, the M4 1295 bit indicates that there is an IPv4 multicast router on a link for 1296 which the originating Intermediate System is appointed forwarder 1297 for every VLAN in the indicated range. The M6 bit indicates the 1298 same for an IPv6 multicast router. The R and Reserved bits MUST 1299 be sent as zero and are ignored on receipt. The VLAN start and 1300 end IDs are inclusive. A range of one VLAN ID is indicated by 1301 setting them both to that VLAN ID value. The Appointed Forwarder 1302 Status Lost Counter is also included here. It is a count of how 1303 many times a port that was appointed forwarder for the VLANs in 1304 the range given has lost the status of being an appointed 1305 forwarder. It has the following format: 1306 0 1 2 3 4 - 15 16 - 19 20 - 31 1307 +----+----+----+----+------------+----------+------------+ 1308 | M4 | M6 | R | R | VLAN start | Reserved | VLAN end | 1309 +----+----+----+----+------------+----------+------------+ 1310 | Appointed Forwarder Status Lost Counter | 1311 +----+----+----+----+------------+----------+------------+ 1313 o Root Bridges: The list of zero or more spanning tree root bridge 1314 IDs is the set of root bridge IDs seen for all ports for which the 1315 Intermediate System is appointed forwarder for the VLANs in the 1316 range. This information is learned from BPDUs heard by the 1317 Intermediate System. If MSTP is in use on a link, the root bridge 1318 referred to is the CIST (common and internal spanning tree) root 1319 bridge. (While, of course, only one spanning tree root should be 1320 seen on any particular port, there may be multiple ports in the 1321 same VLAN connected to differed bridged LANs with different 1322 spanning tree roots.) If no spanning tree roots can be seen on 1323 any of the links in any of the VLANs in the range indicated for 1324 which the Intermediate System is appointed forwarder (for example 1325 all such links are point-to-point links to other Intermediate 1326 Systems or to end stations so no BPDUs are received) then the 1327 listed set of spanning tree root IDs will be null. 1329 If there are any two VLANs in the range indicated for which the value 1330 of the M4, or M6 bits or the Appointed Forwarder Status Lost Counter 1331 are different, the sub-TLV is incorrect and must be split into 1332 multiple sub-TLVs each indicating only VLANs with the same M4, M6, 1333 and Appointed Forwarder Status Lost Counter values. If there are any 1334 two VLANs in the range indicated for which the set of root bridge IDs 1335 see on all links for which the Intermediate System is appointed 1336 forwarder for the VLAN are not the same, the sub-TLV is incorrect and 1337 must be split into multiple sub-TLVs each indicating only VLANs with 1338 the same set of DRB seen root bridge IDs. It is always safe to use 1339 sub-TLVs with a "range" of one VLAN ID but this may be too verbose. 1341 Wherever possible, an implementation SHOULD advertise the update to a 1342 interested vlan and spanning tree roots sub-TLV in the same LSP 1343 fragment as the advertisement that it replaces. Where this is not 1344 possible, the two affected LSP fragments should be flooded as an 1345 atomic action. 1347 Systems that receive an update to an existing interested vlan and 1348 spanning tree roots sub-TLV can minimize the potential disruption 1349 associated with the update by employing a holddown time prior to 1350 processing the update so as to allow for the receipt of multiple LSP 1351 fragments associated with the same update prior to beginning 1352 processing. 1354 Where a receiving system has two copies of a interested vlan and 1355 spanning tree roots sub-TLV from the same system that have different 1356 settings for a given vlan, the procedure used to choose which copy 1357 shall be used is undefined (refer to RFC 4971, Section 3). 1359 This sub-TLV is carried within the CAPABILITY TLV in a level-1 1360 multicast group PDU. 1362 2.4.7. The VLAN Group sub-TLV 1364 The VLAN Group sub-TLV consists of two or more 16-bit fields each of 1365 which has a VLAN ID in the low order 12 bits. The top 4 bits MUST be 1366 sent as zero and ignored on receipt. The first such VLAN ID is the 1367 primary, or may be zero if there is no primary. It is carried within 1368 the CAPABILITY TLV in a level-1 non-pseudo-node LSP and is structured 1369 as follows: 1371 +-+-+-+-+-+-+-+-+ 1372 |Type=VLAN-GROUP| 1373 +-+-+-+-+-+-+-+-+ 1374 | Length | (1 byte) 1375 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1376 | Primary VLAN ID (2 bytes) | 1377 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1378 | Secondary VLAN ID (2 bytes) | 1379 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1380 | more Secondary VLAN IDs ... | 1381 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1383 o Type: TLV Type, set to 11 (VLAN-GROUPs). 1385 o Length: Total number of bytes contained in the value field, 4 + 1386 2*n, where n may be 0. 1388 o Primary VLAN-ID: This identifies the primary VLAN-ID. 1390 o Secondary VLAN-ID: This identifies the secondary VLAN-ID, address 1391 learning is shared at the Intermediate System that announces this 1392 sub-TLV. 1394 This sub-TLV may appear zero, one, or multiple times. It should be 1395 noted that all VLAN ID values described above have a 4 bit reserved 1396 section followed by a 12-bit value. It is carried within the 1397 CAPABILITY TLV. 1399 2.4.8. The Ingress-to-Egress Options (ITEOPT) sub-TLV 1401 By including this sub-TLV within one or more Router Capability TLVs 1402 in its LSPs, an RBridge can advertise the Ingress-to-Egress options 1403 it supports. This sub-TLV may appear zero or more times within a 1404 Router Capability TLV. By default, in the absence of any ITEOPT sub- 1405 TLVs, no Ingress-to-Egress options are supported. 1407 There are two types of Ingress-to-Egress option encoding within the 1408 TRILL Header: bit options and TLV encoded options. 1410 The bit-encoded options supported are indicated by an ITEOPT TLV of 1411 length 3: an initial value byte of 0x00 followed by two bytes in 1412 which each bit indicates that the corresponding bit Ingress-to-Egress 1413 option is implemented. 1415 Other Ingress-to-Egress options are TLV encoded within the TRILL 1416 Header options area. The implementation of a TLV encoded option is 1417 indicated by an ITEOPT sub-TLV whose value starts with a byte equal 1418 to the first byte of the option. Such ITEOPT sub-TLVs may have 1419 additional value bytes further indicating how the option is supported 1420 as specified in the option's definition, for example a list of 1421 supported security algorithms. 1423 +-+-+-+-+-+-+-+-+ 1424 | Type = ITEOPT | 1425 +-+-+-+-+-+-+-+-+ 1426 | Length | (1 byte) 1427 +-+-+-+-+-+-+-+-+ 1428 | Option | (1 byte) 1429 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1430 | Option dependent variable length information | 1431 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1433 o Type: sub-TLV Type, set to Ingress-to-Egress option sub-TLV 12 1434 [TBD]. 1436 o Length: variable, minimum 1. 1438 o Value: Either 0x00 followed by implementation information for bit 1439 encoded options or a non-zero option type byte followed by option 1440 dependent information for that option. 1442 2.4.9. VLAN Mapping (VMAP) sub-TLV 1444 The VLAN Mapping (VMAP) sub-TLV carries information concerning VLAN 1445 mappings configured at the originating IS. VLAN mapping is used when 1446 an RBridge campus is divided into regions such that the same VLAN is 1447 represented by different VLAN IDs in different regions or there is a 1448 VLAN is one region that has no equivalent in another region. Each 1449 port on each of the border RBridges between two or more regions MUST 1450 be configured as to which region each port connects with. The 1451 numbering of regions is an arbitrary choice but all border RBridges 1452 in the campus MUST agree on the number of each region. 1454 +-+-+-+-+-+-+-+-+ 1455 | Type = VMAP | 1456 +-+-+-+-+-+-+-+-+ 1457 | Length | (1 byte) 1458 +-+-+-+-+-+-+-+-+----------...+ 1459 | Mapping 1 | (8 bytes) 1460 +-+-+-+-+-+-+-+------------... 1461 | Mapping N, etc.| 1462 +--------------------------... 1464 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1465 | Count | From VLAN ID | (2 bytes) 1466 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1467 | From Region | (2 bytes) 1468 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1469 | RESV | To VLAN ID | (2 bytes) 1470 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1471 | To Region | (2 bytes) 1472 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1474 o Type: sub-TLV Type, set to VLAN Mapping sub-TLV 13 [TBD]. 1476 o Length: variable, 8*N. 1478 o Value: Specific information on each VLAN mapping as diagrammed 1479 above and specified below: 1481 * Count: If this four bit unsigned integer is zero or 1, then the 1482 mapping of a single VLAN ID is being specified. If it is any 1483 value from 2 through 15, then a block of that many contiguous 1484 VLAN IDs starting with the From VLAN ID is mapped to a block of 1485 that many contiguous VLAN IDs starting with the To VLAN ID. 1487 * From VLAN ID: This is the VLAN ID that, when received on a port 1488 connect to the From Region on a frame being sent to the To 1489 Region, is mapped to the To VLAN ID. This must be a real VLAN 1490 ID, that is, the values 0x000 and 0xFFF are prohibited and 1491 mappings in which they occur are ignored. 1493 * From Region: This is the region number, within the campus, such 1494 that frames received on a port connected to that region and 1495 destined to a port connected to the To Region have their VLAN 1496 ID mapped as specified by the From VLAN ID and To VLAN ID 1497 fields. 1499 * RESV: MUST be sent as zero and ignored on receipt. 1501 * To VLAN ID: This is the VLAN ID to be used on frames sent out a 1502 port connected to the To Region if they were received on a port 1503 connected to the From Region with the From VLAN ID; except that 1504 if the To VLAN ID is 0x000 the frame is dropped. The value 1505 invalid VLAN ID 0xFFF is prohibited in this field and if it 1506 occurs the mapping is ignored. 1508 * To Region: This is the region number, within the campus, such 1509 that frames sent on a port connected to this region from a port 1510 connected to the From Region have their VLAN ID mapped as 1511 specified by the From VLAN ID and To VLAN ID fields. 1513 2.5. Multi Topology Aware Capability TLV 1515 This section defines a new optional Intermediate System to 1516 Intermediate System (IS-IS) TLV named MT-CAPABILITY, formed of 1517 multiple sub-TLVs, which allows a router to announce its capabilities 1518 for a particular topology within an IS-IS level or the entire routing 1519 domain. This is different from Router Capability TLV defined in RFC 1520 4971, in the sense that the capabilities announced here are topology 1521 scoped. 1523 The Multi Topology Aware Capability (MT-CAPABILITY) is an optional 1524 IS-IS TLV type 144 [TBD], that may be generated by the originating IS 1525 and has the following format: 1526 0 1 2 3 1527 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 1528 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1529 |Type=MTCAPABTLV| Length |O|R|R|R| Topology Identifier | 1530 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1531 | sub-TLVs | 1532 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1533 o Type: TLV Type, set to MT-CAPABILITY TLV 144 [TBD]. 1535 o Length: Total number of bytes contained in the value field, 1536 including the length of the sub-TLVs carried in this TLV. 1538 o O bit: The overload bit that follows the semantics associated with 1539 an overloaded intermediate system. 1541 o Reserved (3 bits): Must be sent as zero on transmission and is 1542 ignored on receipt. 1544 o Topology Identifier: MT ID is a 12-bit field containing the MT ID 1545 of the topology being announced. This field when set to zero 1546 implies that it is being used to carry base topology information. 1547 In TRILL this value is set to ZERO, however, in IEEE SPB and SPBB, 1548 it may be non-zero. 1550 o sub-TLVs: The MT aware Capabilities TLV value contains sub-TLVs 1551 formatted as described in [RFC5305]. They are defined in the next 1552 sections. 1554 The MT-CAPABILITY TLV MUST be carried only within a LSP PDU. It may 1555 occur multiple times in a LSP PDU. 1557 2.5.1. SPB Instance sub-TLV 1559 The SPB Instance sub-TLV gives the SPSourceID for this node/topology 1560 instance. This is the 20 bit value that is used in the formation of 1561 multicast DA addresses for packets originating from this node/ 1562 instance. The SPSourceID occupies the upper 20 bits of the multicast 1563 DA together with 4 other bits (see the SPB 802.1ah multicast DA 1564 address format section). 1566 This sub-TLV SHOULD be carried within the MT-Capability TLV in the 1567 fragment ZERO LSP. 1569 +-+-+-+-+-+-+-+-+ 1570 |Type = SPB-Inst| 1571 +-+-+-+-+-+-+-+-+ 1572 | Length | (1 byte) 1573 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1574 | CIST Root Identifier (4 bytes) | 1575 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1576 | CIST Root Identifier (cont) (4 bytes) | 1577 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1578 | CIST External ROOT Path Cost (4 bytes) | 1579 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1580 | Bridge Priority | (2 bytes) 1581 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1582 |R R R R| SPS Flags |V| SPSOURCEID | (4 bytes) 1583 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1584 | Num of Trees | (1 bytes) 1585 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1586 | VLAN-ID (1) Tuples (8 bytes) | 1587 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1588 | VLAN-ID (N) Tuples (8 bytes) | 1589 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1590 | ECT-Alg-Len | (1 bytes) 1591 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1592 | Opaque ECT Algorithm (32 bytes) | 1593 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1594 | Opaque ECT Information (variable ) | 1595 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1597 where VLAN-ID tuples have the format as: 1599 0 1 2 3 1600 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 1601 +-+-+-+-+-+-+-+-+ 1602 |U|M|A| Res | 1603 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1604 | ECT - Algorithm (32 bits) | 1605 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1606 | Base VID 12 bits) | SPTVID 12 bits) | 1607 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1609 o Type: sub-TLV Type, set to SPB Instance sub-TLV 1 [TBD]. 1611 o Length: Total number of bytes contained in the value field. 1613 o CIST Root Identifier (64-bits)The CIST Root Identifier is for SPB 1614 interworking with RSTO and MSTP at SPT RegionBoundaries. This is 1615 an imported value from a Spanning tree. 1617 o CIST External Root Path Cost (32-bits) The CIST External Root Path 1618 Cost is the cost from the Spanning tree algorithm to the Root. 1620 o Bridge Priority (16-bits) Bridge priority is the 16 bits that 1621 together with the low 6 bytes of the System ID form the Bridge 1622 Identifier. The Bridge Identifier is the Spanning tree compatible 1623 Bridge identifier. This is configured exactly as specified in 1624 IEEE802 [802.1D]. This allows SPB to build a compatible Spanning 1625 tree using link state by combining the Bridge Priority and the 1626 System ID to form the 8 byte Bridge Identifier. The 8 byte Bridge 1627 Identifier is also the input to the 16 pre-defined ECT tie breaker 1628 algorithms. 1630 o V bit (1-Bit) The V bit (SPBM) indicates this SPSourceID is auto 1631 allocated(27.11). If the V bit is clear the SPSourceID has been 1632 configured and must be unique. Allocation of SPSourceID is in 1633 [IEEE 802.1aq]. Bridges running SPBM will allocate an SPSourceID 1634 if they are not configured with an explicit SPSourceID. The V Bit 1635 allows neighbor bridges to determine if the auto allocation was 1636 enabled. In the rare chance of a collision of SPsourceID the 1637 bridge with the highest priority Bridge Identifier will win 1638 conflicts and the lower priority Bridge will be re-allocated or if 1639 the lower priority Bridge is configured it will not be allowed to 1640 joint the SPT Region. 1642 o The SPSOURCEID is a 20 bit value used to construct multicast DA's 1643 as described below for multicast packets originating from the 1644 origin (SPB node) of the link state packet (LSP) that contains 1645 this TLV. More details are in [IEEE 802.1aq]. 1647 o Number of Trees (8-bits) The Number of Trees is be set to the 1648 number of [ECT-ALGORITHM, Base-VID plus flags] sub TLV's that 1649 follow. Each ECT-ALGORITHM has an Base VID, an SPVID and some 1650 flags described below. This must be set to at least one ECT. 1651 These define the standard ECTs. 1653 o Each VID Tuple consists of: 1655 * U-Bit (1-bit) The Use flag is set if this bridge is currently 1656 using this ECT-ALGORITHM for I-SIDs it sources or sinks. This 1657 is a bit different than the U-bit found in the Hello, which 1658 will set the Use-Flag if it sees other nodal Use-Flags are set 1659 OR it sources or sinks itself. 1661 * M-Bit (1-bit) The M-bit indicates if this is SPBM or SPBV mode. 1663 * A bit, The A bit (SPB) when set declares this is an SPVID with 1664 auto allocation. The VID allocation logic details are in [IEEE 1665 802.1aq]. Since SPVIDs are from a small pool of resources 1666 (1000 or less) the chances of collision are high. To allow 1667 auto allocation LSPs are exchanged with the allocated bridge 1668 setting the SPVID to 0. 1670 o ECT-ALG-LEN (1 byte): This gives the length of the ECT Algorithm. 1672 o ECT-ALGORITHM (4-bytes) ECT-ALGORITHM is advertised when the 1673 bridge supports a given ECT-ALGORITHM (by OUI/Index) on a given 1674 VID. This declaration must match the declaration in the Hello PDU 1675 originating from the same bridge. The ECT-ALGORITHM, BASE-VID 1676 should match what is generated in the Hellos of the same node. 1677 The ECT-ALGORITHM, BASE-VIDs pairs can come in any order however. 1679 o Base VID (12-bits) The Base-VID that associated the SPT Set via 1680 the ECT-ALGORITHM. 1682 o SPVID (12-bits) The SPVID is the Shortest Path VID when using SPBV 1683 mode. It is not defined for SPBM Mode and should be 0 in SPBM 1684 mode. 1686 o an opaque ECT Data sub-TLV (type TBD) whose first 32 bits are the 1687 ECT-ALGORITHM which this data applies to. 1689 2.5.2. SPBM Service Identifier and Unicast Address sub-TLV 1691 The SPBM Service Identifier and Unicast Address sub-TLV is used to 1692 introduce service group membership on the originating node and/or to 1693 advertise an additional B-MAC unicast address present on, or 1694 reachable by the node. 1696 +-+-+-+-+-+-+-+-+ 1697 |Type = SPBM-SI | 1698 +-+-+-+-+-+-+-+-+ 1699 | Length | (1 byte) 1700 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1701 | B-MAC ADDRESS (6 bytes) | 1702 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1703 | Res. | Base-VID | ( 2 bytes) 1704 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1705 |T|R| Reserved | ISID #1 | (1+3 bytes) 1706 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1707 |T|R| Reserved | ISID #2 | (1+3 bytes) 1708 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1709 |T|R| Reserved | ISID #n | (1+3 bytes) 1710 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1711 o Type: sub-TLV Type, set to SPBM Service Identifier and Unicast 1712 Address sub-TLV 2 [TBD]. 1714 o Length: Total number of bytes contained in the value field. 1716 o B-MAC ADDRESS is a unicast address of this node. It may be either 1717 the single nodal address, or may address a port or any other level 1718 of granularity relative to the node. In the case where the node 1719 only has one B-MAC address this should be the same as the SYS-ID 1720 of the node. To add multiple B-MACs this TLV must be repeated per 1721 additional B-MAC. 1723 o ISID #1 .. #N are 24 bit service group membership identifiers. If 1724 two nodes have an ISID in common, intermediate nodes on the unique 1725 shortest path between them will create forwarding state for the 1726 related B-MAC addresses and will also construct multicast 1727 forwarding state using the ISID and the node's SPSOURCEID to 1728 construct a multicast DA as described in IEEE 802.1aq LSB. Each 1729 ISID has a Transmit(T) and Receive(R) bit which indicates if the 1730 membership is as a Transmitter/Receiver or both (with both bits 1731 set). In the case where the Transmit(T) and Receive(R) bits are 1732 both zero, the ISID is ignored. If more ISIDs are associated with 1733 a particular B-MAC than can fit in a single sub-TLV, this sub-TLV 1734 can be repeated with the same B-MAC but with different ISID 1735 values. 1737 2.6. Sub-TLVs of the Extended Reachability TLV 1739 This section specifies two new sub-TLVs that appear only within the 1740 Extended Reachability TLV (type 22). 1742 2.6.1. SPB Link Metric sub-TLV 1744 The SPB Link Metric sub-TLV occurs within the Extended Reachability 1745 TLV (type 22), or the Multi Topology Intermediate System TLV (type 1746 222). If this sub TLV is not present for an ISIS adjacency then that 1747 adjacency MUST NOT carry SPB traffic for the given topology instance. 1749 +-+-+-+-+-+-+-+-+ 1750 |Type=SPB-Metric| 1751 +-+-+-+-+-+-+-+-+ 1752 | Length | (1 byte) 1753 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1754 | SPB-LINK-METRIC | (3 bytes) 1755 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1756 | Num of ports | (1 byte) 1757 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1758 | Port Identifier | ( 2 bytes) 1759 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1760 | Opaque ECT Algorithm (32 bytes) | 1761 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1762 | Opaque ECT Information (variable ) | 1763 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1765 o Type: sub-TLV Type, set to SPB Link Metric sub-TLV 5 [TBD]. 1767 o Length: Total number of bytes contained in the value field. 1769 o SPB-LINK-METRIC indicates the administrative cost or weight of 1770 using this link as a 24 bit unsigned number. Smaller numbers 1771 indicate lower weights and are more likely to carry SPB traffic. 1772 Only one metric is allowed per SPB instance per link. If multiple 1773 metrics are required multiple SPB instances are required, either 1774 within IS-IS or within several independent IS-IS instances. 1776 o Num of Ports is the number of ports associated with this link. 1778 o Port Identifier is the standard IEEE port identifier used to build 1779 a spanning tree associated with this link. 1781 o an opaque ECT Data sub-TLV (type TBD) whose first 32 bits are the 1782 ECT-ALGORITHM to which this data applies. 1784 2.6.2. MTU sub-TLV 1786 The MTU sub-TLV is used to optionally announce the MTU of a link. It 1787 occurs nested as within the Extended Reachability TLV (type 22). 1789 +-+-+-+-+-+-+-+-+ 1790 | Type = MTU | 1791 +-+-+-+-+-+-+-+-+ 1792 | Length | (1 byte) 1793 +-+-+-+-+-+-+-+-+ 1794 |F| Reserved | (1 byte) 1795 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1796 | MTU | (2 bytes) 1797 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1799 o Type: sub-TLV Type, set to MTU sub-TLV 6 [TBD]. 1801 o Length: Total number of bytes contained in the value field. 1803 o F: Failed. This bit is a one if MTU testing on this link failed 1804 at the required campus-wide MTU. 1806 o MTU: This field is set to the largest successfully tested MTU size 1807 for this link or zero if it has not been tested. 1809 2.7. TRILL Neighbor TLV 1811 The TRILL Neighbor TLV is used in the TRILL-Hello PDU in place of the 1812 IS Neighbor TLV. It differs in that MTU information is provided per 1813 neighbor and provision is made for fragmentation, so that not all 1814 neighbors need be reported in each TRILL-Hello, to support the hard 1815 limit on the size of TRILL-Hellos. This TLV can occur zero, one, or 1816 multiple times in a TRILL-Hello PDU. The structure of the TRILL 1817 Neighbor TLV is as follows: 1819 +-+-+-+-+-+-+-+-+ 1820 | Type = TNeigh | 1821 +-+-+-+-+-+-+-+-+ 1822 | Length | (1 byte) 1823 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1824 |S|L| Reserved | (2 bytes) 1825 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1826 | Neighbor RECORDS (1) | 1827 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1828 | ................. | 1829 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1830 | Neighbor RECORDS (N) | 1831 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1833 The list of neighbors MUST be ordered by MAC address, considering 1834 each 6-byte MAC address to be an unsigned integer, starting with the 1835 smallest. The information present for each neighbor is as follows: 1837 +-+-------------------+ 1838 |F| Reserved | (2 bytes) 1839 +-+-------------------+ 1840 | MTU | (2 bytes) 1841 +--------------------------------------------------------+ 1842 | MAC Address | (6 bytes) 1843 +--------------------------------------------------------+ 1844 o Type: TLV Type, set to TRILL-Neighbor TLV 145 [TBD]. 1846 o Length: Total number of bytes contained in the value field, 2 + 1847 10*n, where n is the number of neighbor records. 1849 o S: smallest flag. If this bit is a one, then the list of 1850 neighbors includes the neighbor with the smallest MAC address. 1852 o L: largest flag. If this bit is a one, then the list of neighbors 1853 includes the neighbor with the largest MAC address. 1855 o Reserved: These bits are reserved for future use and MUST be set 1856 to zero on transmission and ignored on receipt. 1858 o F: failed. This bit is a one if MTU testing to their neighbor 1859 (see Section 2.9.6) failed at the required campus-wide MTU 1861 o MTU: This field is set to the largest successfully tested MTU size 1862 for this neighbor or zero if it has not been tested. 1864 o MAC Address: The MAC address of the neighbor as in the IS Neighbor 1865 RLV (#6). 1867 2.8. The Group Membership Active Source TLV 1869 The Group Active Source (GMAS) TLV is IS-IS TLV type 146 [TBD] and 1870 has the following format: 1872 +-+-+-+-+-+-+-+-+ 1873 | Type = GMAS | (1 byte) 1874 +-+-+-+-+-+-+-+-+ 1875 | Length | (1 byte) 1876 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1877 | sub-TLVs (variable bytes) | 1878 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1880 o Type: TLV Type, set to GMAS-TLV 146 [TBD]. 1882 o Length: Total number of bytes contained in the value field, which 1883 includes the length of the sub-TLVs carried in this TLV. 1885 o sub-TLVs: The Group Active Source TLV value contains sub-TLVs 1886 formatted as described in [RFC5305]. The sub-TLVs for this TLV 1887 are specified in the following subsections. 1889 The GMAS TLV is carried within Multicast Group Level 1 link state 1890 PDU. 1892 2.8.1. The Group MAC Active Source sub-TLV 1894 The Group MAC Source (GMAS-MAC) sub-TLV is IS-IS sub-TLV type 1 1895 within the GMAS TLV. It is used in OTV [OTV] to create multicast 1896 distribution trees and has the following format: 1898 +-+-+-+-+-+-+-+-+ 1899 | Type=GMAS-MAC | (1 byte) 1900 +-+-+-+-+-+-+-+-+ 1901 | Length | (1 byte) 1902 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1903 |G|S| R | Vlan ID | (2 byte) 1904 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1905 | Address family | (2 bytes) 1906 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1907 | Length | (1 byte) 1908 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1909 | Delivery group (afi scoped number of bytes) | 1910 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1911 | Delivery Source (afi scoped number of bytes) | 1912 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1913 |Num Group Recs | (1 byte) 1914 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1915 | GROUP RECORDS (1) | 1916 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1917 | ................. | 1918 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1919 | GROUP RECORDS (N) | 1920 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1922 where each group record is of the form: 1924 +-+-+-+-+-+-+-+-+ 1925 | RESERVED | (1 byte) 1926 +-+-+-+-+-+-+-+-+ 1927 | Num of Sources| (1 byte) 1928 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1929 | Group Address (6 bytes) | 1930 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1931 | Source 1 Address (6 bytes) | 1932 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1933 | Source 2 Address (6 bytes) | 1934 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1935 | Source M Address (6 bytes) | 1936 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1937 o Type: sub-TLV Type, set to 1 (GMAS-MAC) of length 1 byte. 1939 o Length: Total number of bytes contained in the value field. 1941 o G (1 bit): Delivery Group is set 1943 o S (1 bit): Delivery Source is set 1945 o RESERVED (2 bits) : Must be sent as zero on transmission and is 1946 ignored on receipt. 1948 o VLAN-ID: This carries a 12-bit VLAN identifier that is valid for 1949 all subsequent MAC addresses in this sub-TLV, or the value zero if 1950 no VLAN is specified. 1952 o Address Family: Describes the Address family of the Delivery 1953 Source/Group information. 1955 o Length: Gives the length of the Delivery Source and Delivery Group 1956 field. 1958 o Delivery Group: Describes the group used to deliver packets. 1960 o Delivery Source: Describes the source address used to deliver 1961 packets. 1963 o Number of Group Records: This is of length 1 byte and lists the 1964 number of group records in this sub-TLV. 1966 o Group Record: Each group record has a one byte reserved space and 1967 the next byte carries the number of sources. It then has a 48-bit 1968 multicast Group Address followed by 48-bit source MAC addresses. 1969 An address being a group multicast address or unicast source 1970 address can be checked using the multicast bit in the address. If 1971 the number of sources do not fit in a single sub-TLV, it is 1972 permitted to have the same group address repeated with different 1973 source addresses in another sub-TLV of another instance of the 1974 Group Active Source TLV. 1976 The GMAS-MAC sub-TLV is carried within the GMAS TLV and MUST be 1977 carried in a standard Level 1 link state MGROUP PDU. 1979 2.8.2. The Group IP Active Source sub-TLV 1981 The Group IP Address (GMAS-IP) sub-TLV is IS-IS TLV type 2. It is 1982 used in OTV [OTV] to create multicast distribution trees and has the 1983 following format: 1985 +-+-+-+-+-+-+-+-+ 1986 | Type=GMAS-IP | (1 byte) 1987 +-+-+-+-+-+-+-+-+ 1988 | Length | (1 byte) 1989 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1990 |G|S| R | Vlan ID | (2 byte) 1991 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1992 | Address family | (2 bytes) 1993 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1994 | Length | (1 byte) 1995 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1996 | Delivery group (afi scoped number of bytes) | 1997 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1998 | Delivery Source (afi scoped number of bytes) | 1999 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2000 |Num Group Recs | (1 byte) 2001 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2002 | GROUP RECORDS (1) | 2003 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2004 | ................. | 2005 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2006 | GROUP RECORDS (N) | 2007 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2009 where each group record is of the form: 2011 +-+-+-+-+-+-+-+-+ 2012 | RESERVED | (1 byte) 2013 +-+-+-+-+-+-+-+-+ 2014 | Num of Sources| (1 byte) 2015 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2016 | Group Address (4 bytes) | 2017 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2018 | Source 1 Address (4 bytes) | 2019 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2020 | Source 2 Address (4 bytes) | 2021 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2022 | Source M Address (4 bytes) | 2023 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2025 o Type: sub-TLV Type, set to 2 (GIP-ADDR). 2027 o Length: Total number of bytes contained in the value field of the 2028 sub-TLV. 2030 o G (1 bit): Delivery Group is set 2031 o S (1 bit): Delivery Source is set 2033 o RESERVED (2 bits) : Must be sent as zero on transmission and is 2034 ignored on receipt. 2036 o VLAN-ID: This carries a 12-bit VLAN identifier that is valid for 2037 all subsequent MAC addresses in this sub-TLV, or the value zero if 2038 no VLAN is specified. 2040 o Address Family: Describes the Address family of the Delivery 2041 Source/Group information. 2043 o Length: Gives the length of the Delivery Source and Delivery Group 2044 field. 2046 o Delivery Group: Describes the group used to deliver packets. 2048 o Delivery Source: Describes the source address used to deliver 2049 packets. 2051 o Number of Group Records: This is of length 1 byte and lists the 2052 number of group records in this sub-TLV. 2054 o Group Record: Each group record has a one byte reserved space and 2055 the next byte carries the number of sources. It is followed by a 2056 32-bit IPv4 Group Address followed by 32-bit source IPv4 2057 addresses. If the number of sources do not fit in a single sub- 2058 TLV, it is permitted to have the same group address repeated with 2059 different source addresses repeated in another sub-TLV of another 2060 instance of the Group Active Source TLV. 2062 The GMAS-IP TLV is carried within the GMAS TLV and MUST be carried in 2063 a standard Level 1 link state MGROUP PDU. 2065 2.8.3. The Group IPv6 Active Source sub-TLV 2067 The Group IPv6 Active Source (GMAS-IPv6) sub-TLV is IS-IS sub-TLV 2068 type 3. It is used in OTV [OTV] to create multicast distribution 2069 trees and has the following format: 2071 +-+-+-+-+-+-+-+-+ 2072 | Type=GMAS-IP | (1 byte) 2073 +-+-+-+-+-+-+-+-+ 2074 | Length | (1 byte) 2075 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2076 |G|S| R | Vlan ID | (2 byte) 2077 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2078 | Address family | (2 bytes) 2079 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2080 | Length | (1 byte) 2081 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2082 | Delivery group (afi scoped number of bytes) | 2083 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2084 | Delivery Source (afi scoped number of bytes) | 2085 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2086 |Num Group Recs | (1 byte) 2087 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2088 | GROUP RECORDS (1) | 2089 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2090 | ................. | 2091 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2092 | GROUP RECORDS (N) | 2093 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2095 where each group record is of the form: 2097 +-+-+-+-+-+-+-+-+ 2098 | RESERVED | (1 byte) 2099 +-+-+-+-+-+-+-+-+ 2100 | Num of Sources| (1 byte) 2101 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2102 | Group Address (16 bytes) | 2103 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2104 | Source 1 Address (16 bytes) | 2105 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2106 | Source 2 Address (16 bytes) | 2107 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2108 | Source M Address (16 bytes) | 2109 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2111 o Type: sub-TLV Type, set to 3 (GIPV6-ADDR). 2113 o Length: Total number of bytes contained in the value field. 2115 o G (1 bit): Delivery Group is set 2117 o S (1 bit): Delivery Source is set 2118 o RESERVED (2 bits) : Must be sent as zero on transmission and is 2119 ignored on receipt. 2121 o VLAN-ID: This carries a 12-bit VLAN identifier that is valid for 2122 all subsequent MAC addresses in this sub-TLV, or the value zero if 2123 no VLAN is specified. 2125 o Address Family: Describes the Address family of the Delivery 2126 Source/Group information. 2128 o Length: Gives the length of the Delivery Source and Delivery Group 2129 field. 2131 o Delivery Group: Describes the group used to deliver packets. 2133 o Delivery Source: Describes the source address used to deliver 2134 packets. 2136 o Number of Group Records: This of length 1 byte and lists the 2137 number of group records in this sub-TLV. 2139 o Group Record: Each group record has a one byte reserved space and 2140 the next byte carries the number of sources. It is followed by a 2141 128-bit multicast IPv6 Group Address followed by 128-bit source 2142 IPv6 addresses. If the number of sources do not fit in a single 2143 sub-TLV, it is permitted to have the same group address repeated 2144 with different source addresses repeated in another sub-TLV in 2145 another instance of the Group Address TLV. 2147 The GMAS-IPv6 sub-TLV is carried within the GMAS TLV and MUST be 2148 carried in a standard Level 1 link state MGROUP PDU. 2150 2.9. PDU Extensions to IS-IS 2152 2.9.1. The Multicast Group PDU 2154 The systems that this document is concerned with want to carry not 2155 only layer-2 unicast information in the link state protocols, but 2156 also multicast information. This section specifies three new IS-IS 2157 PDUs, the Multicast Group (MGROUP) PDU, for carrying a list of 2158 attached or joined multicast groups. The Multicast Group Complete 2159 Sequence Number (MGROUP-CSNP) PDU and the Multicast Group Partial 2160 Sequence Number (MGROUP-PSNP) PDU packets are also defined to be used 2161 with the new MGROUP-PDU to perform database exchange on the MGROUP 2162 PDU packets. 2164 In the Layer-2 environment, it is expected the join/leave frequency 2165 of the multicast members will be much higher than unicast topology 2166 changes. It is efficient to separate the updates for the group 2167 membership change information from the remainder of the information 2168 by placing this information in a separate PDU. This enables 2169 reachability information, that would trigger an SPF, to be not 2170 impacted at all. Furthermore, during SPF runs, TLVs being on 2171 different PDUs which do not affect SPF need not be inspected during 2172 processing. 2174 The choice of a different PDU also opens the LSP-space to another 256 2175 fragments to carry a large number of groups. This additional space 2176 can be used judiciously to carry only multicast information. 2178 The Multicast Group (MGROUP) PDU can be used to advertise a set of 2179 attached, or joined, multicast groups. The MGROUP PDU is formatted 2180 identical to a Level 1 Link State PDU, as described in Section 9.3 of 2181 [IS-IS]. One field, PDU Type, is changed to 19 [TBD], to signify 2182 this PDU is carrying multicast group information, rather than unicast 2183 reachability information. 2185 The Multicast Group PDU carries TLVs indicating multicast membership 2186 information. There are three sub-TLVs of the GADDR TLV defined in 2187 this document, that MAY be present in this PDU, namely, GMAC-ADDR, 2188 GIP-ADDR, and GIPV6-ADDR sub-TLVs. Furthermore, it MAY carry the 2189 interested vlan sub-TLV of the Capability TLV. 2191 One or more TLVs MAY be carried in a single MGROUP PDU. Future 2192 multicast address TLVs MAY be defined using other type codes, and be 2193 carried in an MGROUP PDU. 2195 The information carried in this PDU is processed in a similar fashion 2196 as described in [RFC 1584]. 2198 2.9.2. The Multicast Group Partial Sequence Number PDU 2200 The Multicast Group Partial Sequence Number (MGROUP-PSNP) PDU is used 2201 to reliably flood the MGROUP PDU following the base protocol 2202 specifications. 2204 2.9.3. The Multicast Group Complete Sequence Number PDU 2206 The Multicast Group Complete Sequence Number PDU (MGROUP-CSNP) PDU is 2207 used to reliably flood the MGROUP PDU following the base protocol 2208 specifications. 2210 2.9.4. MGROUP PDU related changes to Base protocol 2212 In this section, we describe the changes to the base protocol due to 2213 the introduction of the MGROUP, MGROUP-PSNP, MGROUP-CNSP PDUs. 2215 2.9.4.1. Enhancements to the flooding process 2217 This document specifies that the information contained in the MGROUP- 2218 PDU is in a parallel database and its update mechanisms mimic that of 2219 the regular database. Nodes running IS-IS in an L2 domain MUST 2220 support these additional MGROUP PDUs defined in this document. In 2221 general, the flooding of the MGROUP-PDU in tandem with the MGROUP- 2222 PSNP and MGROUP-CSNP PDUs uses the same update procedures as defined 2223 for the regular LSP, PSNP, and CSNP PDUs. 2225 For example, on P2P links CSNP is exchanged on the formation of an 2226 adjacency. In a similar fashion a MGROUP-CSNP MUST also be exchanged 2227 between the neighbors at the same time. This gets the initial 2228 MGROUP-database synchronization going. After this similar actions of 2229 the base protocol specifications for the regular database 2230 synchronization will be maintained to keep the MGROUP-database 2231 synchronized. There need not be any more correlation between the 2232 updates of the regular PDU and the MGROUP-PDU. 2234 Similarly, on LAN links the DIS is responsible for sending periodic 2235 CSNP transmissions. The DIS in the L2 IS-IS network domain will also 2236 be responsible for sending periodic MGROUP-CSNP transmissions. The 2237 update and flooding process will work in parallel for the two 2238 databases and there is no further synchronization between them. 2240 In general, the database synchronization is performed in parallel 2241 with no interactions between the messages. However, the initial 2242 triggers that start a CSNP exchange are correlated, in the sense it 2243 also triggers a MGROUP-CSNP exchange. 2245 2.9.4.2. Enhancements to Graceful Restart 2247 During graceful restart [RFC 5306], the normal hello operations as 2248 described in the RFC will be followed. The enhancements will take 2249 place such that CSNP and PSNP triggers will necessitate a parallel 2250 MGROUP-CSNP and MGROUP-PSNP exchange and update process will be 2251 triggered in parallel for the MGROUP-PDUs. After both databases 2252 containing the regular PDUs and MGROUP-PDUs have been obtained, the 2253 restart process is deemed complete. 2255 2.9.4.3. Enhancements to the maximum sequence number reached 2257 In the event, LSPs reach the maximum sequence number, ISO/IEC 10589 2258 states the rules for the process to shut down and its duration. With 2259 the introduction of the MGROUP-PDU, the same process now applies when 2260 LSPs from either database reach the maximum sequence number. 2262 2.9.4.4. Enhancements to the SPF 2264 The MGROUP-PDU advertises a set of attached, or joined, multicast 2265 groups. These groups act as leaves of the advertising nodes. As a 2266 result, there are no new requirements of running a SPF if only 2267 information within the MGROUP-PDU changes. 2269 2.9.5. The TRILL-Hello PDU 2271 A different Hello PDU is required for TRILL links because it is 2272 necessary that a single Designated RBridge (DIS) be elected on each 2273 link based just on priority and MAC address regardless of two-way 2274 connectivity. However, RBridge reachability is reported by RBridges 2275 in their LSP on the same basis as layer 3 Intermediate Systems report 2276 reachability, that is, if and only if two-way connectivity exists. 2278 The TRILL-Hello PDU has the same general structure as an IS-IS LAN 2279 PDU. An RBridge (an Intermediate System supporting TRILL) sends this 2280 PDU, with the same timing as the IS-IS LAN Hello PDU. More 2281 specifically, in a TRILL-Hello PDU the IS-IS Common Header and the 2282 fixed PDU Header are the same as a Level 1 IS-IS LAN Hello except 2283 that a new PDU Type number is used as listed in Section 5. The 2284 circuit type field, of course, is always equal to one. A TRILL-Hello 2285 PDU SHOULD not be padded and MUST NOT exceed a length limit equal to 2286 42 bytes shorter than the reasonable lower bound for the link MTU. 2287 For example, for an 802.3 Ethernet link, the MTU SHOULD be assumed to 2288 be 1512 bytes for the purpose of determining the maximum size of 2289 TRILL-Hello PDUs on that link. Thus, for such a link, TRILL-Hellos 2290 MUST NOT exceed 1470 bytes. 2292 The following MUST appear in every TRILL-Hello PDU: a Port Capability 2293 TLV (see Section 2.3) containing a Special VLANs and Flags sub-TLV. 2295 Additional TLVs/sub-TLVs MAY appear in a TRILL-Hello including the 2296 TRILL Neighbor TLV specified in Section 2.7 and the following sub- 2297 TLVs specified in Section 2.3: Enabled VLANs sub-TLV, Appointed 2298 Forwarders sub-TLV, and Hop-by-Hop Options sub-TLV. 2300 The Padding TLV (#8) SHOULD NOT appear in a TRILL-Hello. 2302 The IS-IS Neighbor TLV (#6) MUST NOT appear in a TRILL-Hello. 2303 Instead, it uses the TRILL Neighbor TLV (see Section 2.7). 2305 2.9.6. The MTU PDU 2307 The MTU-probe and MTU-ack PDUs are used to determine the MTU on a 2308 link between intermediate systems. An MTU-probe MUST be padded to 2309 the size being tested with the Padding TLV (#8). The ability to send 2310 an MTU-probe PDU is optional but an Intermediate System that supports 2311 TRILL MUST send an MTU-ack in response to an MTU-probe and that MTU- 2312 ack MUST be padded to the size of the MTU-probe. 2314 The MTU PDUs have the standard IS-IS common header with two new PDU 2315 Type numbers, one each, as listed in Section 5. They also have a 20- 2316 byte common fixed MTU PDU header as shown below. 2318 +------------+ 2319 | PDU Length | (2 bytes) 2320 +------------+-------------------------+ 2321 | Probe ID | (6 bytes) 2322 +--------------------------------------+ 2323 | Probe Source ID | (6 bytes) 2324 +--------------------------------------+ 2325 | Ack Source ID | (6 bytes) 2326 +--------------------------------------+ 2328 As with other IS-IS PDUs, the PDU length contains length of the 2329 entire IS-IS packet starting with and including the IS-IS common 2330 header. 2332 The Probe ID field is an arbitrary 48-bit quantity set by the 2333 Intermediate System issuing an MTU-probe and copied by the responding 2334 system into the corresponding MTU-ack. For example, an Intermediate 2335 System creating an MTU-probe could compose this quantity from a port 2336 identifier and probe sequence number relative to that port. 2338 The Probe Source ID is set by an Intermediate system issuing an MTU- 2339 probe to its System ID and copied by the responding system into the 2340 corresponding MTU-ack. 2342 The Ack Source ID is set to zero in MTU-probe PDUs. An Intermediate 2343 System issuing an MTU-ack set this field to its System ID. 2345 The TLV area follows the MTU PDU header area. This area MAY contain 2346 an Authentication TLV and MUST be padded to the size being tested 2347 with the Padding TLV. 2349 3. Acknowledgements 2351 The authors would like to thank Les Ginsberg and Mike Shand for their 2352 useful comments. 2354 4. Security Considerations 2356 This document adds no additional security risks to IS-IS, nor does it 2357 provide any additional security for IS-IS. 2359 5. IANA Considerations 2361 This document creates six new PDU types, namely the MGROUP PDU, 2362 MGROUP-CSNP PDU, the MGROUP-PSNP PDU, TRILL-HELLO-PDU, MTU-PROBE-PDU, 2363 and MTU-ACK-PDU. IANA SHOULD assign a new PDU type to the level-1 2364 PDUs described above and reflect it in the PDU registry. 2366 MGROUP-PDU Level-1 PDU Type: 19 2367 MGROUP-CSNP-PDU Level-1 PDU Type: 22 2368 MGROUP-PSNP-PDU Level-1 PDU Type: 29 2369 TRILL-HELLO-PDU Level-1 PDU Type: 21 2370 MTU-PROBE-PDU Level-1 PDU Type: 23 2371 MTU-ACK-PDU Level-1 PDU Type: 28 2373 This document specifies the definition of a set of new IS-IS TLVs, 2374 the MAC-Reachability TLV (type 141), the Group Address TLV (type 2375 142), the Port-Capability TLV (type 143), the MT-Capability TLV (type 2376 144), and the Trill-Neighbor TLV (type 145), and Group Member Active 2377 Source TLV (type 146) that need to be reflected in the IS-IS TLV 2378 code-point registry. 2380 This document creates a number of new sub-TLVs in the numbering space 2381 for the Group Address TLV, the MT Port Capability TLV, the Extended 2382 Reachability TLV, the MT-Capability TLV, and the Capability TLV. The 2383 TLV and sub-TLVs are given below along with technologies that use 2384 them. 2386 IIH LSP SNP MGROUP MGROUP TRILL/ 2387 LSP SNP IEEE/OTV 2388 MAC-RI TLV (141) - X - - - T/I/O 2390 GADDR-TLV (142) - - - X - T/I/O 2391 GADDR-TLV.GMAC-ADDR sub-TLV 1 - - - X - T/-/O 2392 GADDR-TLV.GMAC-IP sub-TLV 2 - - - X - T/-/O 2393 GADDR-TLV.GMAC-IPV6 sub-TLV 3 - - - X - T/-/O 2394 GADDR-TLV.SPBV-MAC-ADDR sub-TLV 4 - - - X - -/I/- 2396 MT-Port-Cap-TLV (143) X - - - - T/I/O 2397 PortCap.VLAN and Flags sub-TLV 1 X - - - - T/-/- 2398 PortCap.Enabled-VLANs sub-TLV 2 X - - - - T/-/- 2399 PortCap.AppointedFwrdrs sub-TLV 3 X - - - - T/-/- 2400 PortCap.HBHOPT sub-TLV 4 X - - - - T/-/- 2401 PortCap.BaseVLANID sub-TLV 5 X - - - - -/I/- 2402 PortCap.SPBDigest sub-TLV 6 X - - - - -/I/- 2403 PortCap.SiteIdentifier sub-TLV 250 X - - - - -/-/O 2404 PortCap.SiteGroupIP sub-TLV 251 X - - - - -/-/O 2405 PortCap.SiteGroupIPv6 sub-TLV 252 X - - - - -/-/O 2406 PortCap.AdjServerIP sub-TLV 253 X - - - - -/-/O 2407 PortCap.AdjServerIPv6 sub-TLV 254 X - - - - -/-/O 2409 CAPABILITY.Trill-Version sub-TLV 5 - X - X - T/-/- 2410 CAPABILITY.Nickname sub-TLV 6 - X - - - T/-/- 2411 CAPABILITY.Tree sub-TLV 7 - X - - - T/-/- 2412 CAPABILITY.Tree Id sub-TLV 8 - X - - - T/-/- 2413 CAPABILITY.TreeUseRootId sub-TLV 9 - X - - - T/-/- 2414 CAPABILITY.Int-VLANs sub-TLV 10 - - - X - T/-/- 2415 CAPABILITY.VLAN-Groups sub-TLV 11 - X - - - T/-/- 2416 CAPABILITY.ITEOPT sub-TLV 12 - X - - - T/-/- 2417 CAPABILITY.VMAP sub-TLV 13 - X - - - T/-/- 2419 MT-Capability-TLV (144) - X - - - -/I/- 2420 MT-Cap.SPB Instance sub-TLV 1 - X - - - -/I/- 2421 MT-Cap.Service Id. sub-TLV 2 - X - - - -/I/- 2423 TRILL-Nieghbor TLV (145) X - - - - T/-/- 2425 EXT-IS.SPB Link Metric sub-TLV 5 - X - - - -/I/- 2426 EXT-IS.MTU sub-TLV 6 - X - - - T/-/- 2427 MT-EXT-IS.SPB LinkMetric sub-TLV 5 - X - - - -/I/- 2429 Group Mem Active Source TLV (146) - - - X - -/-/O 2430 GMAS-TLV.GMAS-MAC sub-TLV 1 - - - X - -/-/O 2431 GMAS-TLV.GMAS-IP sub-TLV 2 - - - X - -/-/O 2432 GMAS-TLV.GMAS-IPV6 sub-TLV 3 - - - X - -/-/O 2433 IANA SHOULD manage the remaining space using the IETF Review method 2434 [RFC 5226]. 2436 6. References 2438 6.1. Normative References 2440 [IS-IS] ISO/IEC 10589, "Intermediate System to Intermediate System 2441 Intra-Domain Routing Exchange Protocol for use in 2442 Conjunction with the Protocol for Providing the 2443 Connectionless-mode Network Service (ISO 8473)", 2005. 2445 [RFC 1195] 2446 Callon, R., "Use of OSI IS-IS for Routing in TCP/IP and 2447 Dual Environments", 1990. 2449 [RFC 4971] 2450 Vasseur, JP. and N. Shen, "Intermediate System to 2451 Intermediate System (IS-IS) Extensions for Advertising 2452 Router Information", 2007. 2454 [RFC 5305] 2455 Li, T. and H. Smit, "IS-IS Extensions for Traffic 2456 Engineering", 2008. 2458 [RFC 5306] 2459 Shand, M. and L. Ginsberg, "Restart Signaling for 2460 Intermediate System to Intermediate System (IS-IS)", 2004. 2462 6.2. Informative References 2464 [IEEE 802.1aq] 2465 "Standard for Local and Metropolitan Area Networks / 2466 Virtual Bridged Local Area Networks / Amendment 9: 2467 Shortest Path Bridging, Draft IEEE P802.1aq/D1.5", 2008. 2469 [OTV] Grover, H., Farinacci, D., and D. Rao, "OTV: Overlay 2470 Transport Virtualization", draft-hasmit-otv-00, 2010. 2472 [RBRIDGES] 2473 Perlman, R., Eastlake, D., Dutt, D., Gai, S., and A. 2474 Ghanwani, "RBridges: Base Protocol Specification", 2010. 2476 [RFC 1584] 2477 Moy, J., "Multicast Extensions to OSPF", March 1994. 2479 Authors' Addresses 2481 Ayan Banerjee (editor) 2482 Cisco Systems 2483 170 W Tasman Drive 2484 San Jose, CA 95138 2485 US 2487 Email: ayabaner@cisco.com 2489 David Ward 2490 Juniper Networks 2491 1194 N. Mathilda Ave. 2492 Sunnyvale, CA 94089-1206 2493 USA 2495 Phone: +1-408-745-2000 2496 Email: dward@juniper.net 2498 Russ White 2499 Cisco Systems 2500 170 W Tasman Drive 2501 San Jose, CA 95138 2502 US 2504 Email: riw@cisco.com 2506 Dino Farinacci 2507 Cisco Systems 2508 170 W Tasman Drive 2509 San Jose, CA 95138 2510 US 2512 Email: dino@cisco.com 2514 Radia Perlman 2515 Intel Labs 2516 2200 Mission College Blvd. 2517 Santa Clara, CA 95054 2518 US 2520 Phone: +1-408-765-8080 2521 Email: Radia.Perlman@alum.mit.edu 2522 Donald E. Eastlake 3rd 2523 Stellar Switches 2524 155 Beaver Street 2525 Milford, MA 07157 2526 US 2528 Phone: +1-508-333-2270 2529 Email: d3e3e3@gmail.com 2531 Peter Ashwood-Smith 2532 Huawei Technologies Canada Co. Ltd. 2533 411 Legget Drive, Suite 503 2534 Kanta, Ontario K2K 3C9 2535 CANADA 2537 Email: Peter.AshwoodSmith@huawei.com 2539 Don Fedyk 2540 Alcatel-Lucent 2541 220 Hayden Road 2542 Groton, MA 01450 2543 US 2545 Email: Donald.Fedyk@alcatel-lucent.com