idnits 2.17.1 draft-psenak-ospf-bier-extensions-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document doesn't use any RFC 2119 keywords, yet seems to have RFC 2119 boilerplate text. -- The document date (September 27, 2014) is 3499 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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-13) exists of draft-ietf-ospf-prefix-link-attr-01 == Outdated reference: A later version (-05) exists of draft-wijnands-bier-architecture-00 == Outdated reference: A later version (-02) exists of draft-wijnands-mpls-bier-encapsulation-00 Summary: 0 errors (**), 0 flaws (~~), 5 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 OSPF P. Psenak, Ed. 3 Internet-Draft N. Kumar 4 Intended status: Standards Track IJ. Wijnands 5 Expires: March 31, 2015 Cisco 6 A. Dolganow 7 Alcatel-Lucent 8 September 27, 2014 10 OSPF Extensions For BIER 11 draft-psenak-ospf-bier-extensions-00.txt 13 Abstract 15 Bit Index Explicit Replication (BIER) is an architecture that 16 provides optimal multicast forwarding through a "BIER domain" without 17 requiring intermediate routers to maintain any multicast related per- 18 flow state. BIER also does not require any explicit tree-building 19 protocol for its operation. A multicast data packet enters a BIER 20 domain at a "Bit-Forwarding Ingress Router" (BFIR), and leaves the 21 BIER domain at one or more "Bit-Forwarding Egress Routers" (BFERs). 22 The BFIR router adds a BIER header to the packet. The BIER header 23 contains a bit-string in which each bit represents exactly one BFER 24 to forward the packet to. The set of BFERs to which the multicast 25 packet needs to be forwarded is expressed by setting the bits that 26 correspond to those routers in the BIER header. 28 This document describes the OSPF protocol extension required for BIER 29 with MPLS encapsulation. 31 Status of This Memo 33 This Internet-Draft is submitted in full conformance with the 34 provisions of BCP 78 and BCP 79. 36 Internet-Drafts are working documents of the Internet Engineering 37 Task Force (IETF). Note that other groups may also distribute 38 working documents as Internet-Drafts. The list of current Internet- 39 Drafts is at http://datatracker.ietf.org/drafts/current/. 41 Internet-Drafts are draft documents valid for a maximum of six months 42 and may be updated, replaced, or obsoleted by other documents at any 43 time. It is inappropriate to use Internet-Drafts as reference 44 material or to cite them other than as "work in progress." 46 This Internet-Draft will expire on March 31, 2015. 48 Copyright Notice 50 Copyright (c) 2014 IETF Trust and the persons identified as the 51 document authors. All rights reserved. 53 This document is subject to BCP 78 and the IETF Trust's Legal 54 Provisions Relating to IETF Documents 55 (http://trustee.ietf.org/license-info) in effect on the date of 56 publication of this document. Please review these documents 57 carefully, as they describe your rights and restrictions with respect 58 to this document. Code Components extracted from this document must 59 include Simplified BSD License text as described in Section 4.e of 60 the Trust Legal Provisions and are provided without warranty as 61 described in the Simplified BSD License. 63 Table of Contents 65 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 66 2. Flooding of the BIER Information in OSPF . . . . . . . . . . 3 67 2.1. The BIER MPLS Sub-TLV . . . . . . . . . . . . . . . . . . 3 68 3. Security Considerations . . . . . . . . . . . . . . . . . . . 5 69 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 70 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5 71 6. Normative References . . . . . . . . . . . . . . . . . . . . 5 72 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 74 1. Introduction 76 Bit Index Explicit Replication (BIER) is an architecture that 77 provides optimal multicast forwarding through a "BIER domain" without 78 requiring intermediate routers to maintain any multicast related per- 79 flow state. BIER also does not require any explicit tree-building 80 protocol for its operation. A multicast data packet enters a BIER 81 domain at a "Bit-Forwarding Ingress Router" (BFIR), and leaves the 82 BIER domain at one or more "Bit-Forwarding Egress Routers" (BFERs). 83 The BFIR router adds a BIER header to the packet. The BIER header 84 contains a bit-string in which each bit represents exactly one BFER 85 to forward the packet to. The set of BFERs to which the multicast 86 packet needs to be forwarded is expressed by setting the bits that 87 correspond to those routers in the BIER header. 89 BIER architecture requires routers participating in BIER within a 90 given BIER domain to exchange some BIER specific information among 91 themselves. BIER architecture allows link-state routing protocols to 92 perform the distribution of these information. In this document we 93 describe extensions to OSPF to distribute BIER specific information 94 for the case where BIER uses MPLS encapsulation as described in 95 [I-D.wijnands-mpls-bier-encapsulation]. 97 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 98 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 99 document are to be interpreted as described in [RFC2119]. 101 2. Flooding of the BIER Information in OSPF 103 All the BIER specific information that a BIER router needs to 104 advertise to other BIER routers are associated with the BFR-Prefix, a 105 unique (within a given BIER domain), routable IP address that is 106 assign to each BIER router as described in section 2 of 107 [I-D.wijnands-bier-architecture]. 109 Given that the BIER information is associated with the prefix, the 110 OSPF Extended Prefix Opaque LSA [I-D.ietf-ospf-prefix-link-attr] is 111 used to flood BIER related information. 113 2.1. The BIER MPLS Sub-TLV 115 A new Sub-TLV of the Extended Prefix TLV (defined in 116 [I-D.ietf-ospf-prefix-link-attr]) is defined for distributing BIER 117 information. The new Sub-TLV is called BIER MPLS Sub-TLV. Multiple 118 BIER MPLS Sub-TLVs may be included in the Extended Prefix TLV. 120 BIER MPLS Sub-TLV has the following format: 122 0 1 2 3 123 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 1 124 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 125 | Type | Length | 126 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 127 | BS Length | MT-ID | BFR-id | 128 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 129 |Lbl Range Size | Label Range Base | 130 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 132 Type: TBD 134 Length: 8 bytes 136 BS Length: A 1 octet field encoding the supported BitString length 137 associated with this BFR-prefix. The values allowed in this field 138 are specified in section 3 of 139 [I-D.wijnands-mpls-bier-encapsulation]. 141 MT-ID: Multi-Topology ID (as defined in [RFC4915]). 143 BFR-id: A 2 octet field encoding the BFR-id, as documented in 144 section 2 [I-D.wijnands-bier-architecture]. 146 Label Range Size: A 1 octet field encoding the label range size of 147 the label range. 149 Label Range Base: A 3 octet field, where the 20 rightmost bits 150 represent the first label in the label range. 152 The "label range" is the set of labels beginning with the label 153 range base and ending with (label range base)+(label range size)- 154 1. A unique label range is allocated for each BitStream length 155 and Multi-Topology ID. These labels are used for BIER forwarding 156 as described in [I-D.wijnands-bier-architecture] and 157 [I-D.wijnands-mpls-bier-encapsulation]. 159 The size of the label range is determined by the number of Set 160 Identifiers (SI) (section 2 of [I-D.wijnands-bier-architecture]) 161 that are used in the network. Each SI maps to a single label in 162 the label range. The first label is for SI=0, the second label is 163 for SI=1, etc. 165 Flooding scope of the OSPF Extended Prefix Opaque LSA 166 [I-D.ietf-ospf-prefix-link-attr] that is used for advertising BIER 167 MPLS Sub TLV is set to area. If (and only if) a single BIER domain 168 contains multiple OSPF areas, OSPF must propagate BIER information 169 between areas. The following procedure is used in order to propagate 170 BIER related information between areas: 172 When an OSPF ABR advertises a Type-3 Summary LSA from an intra- 173 area or inter-area prefix to all its connected areas, it will also 174 originate an Extended Prefix Opaque LSA, as described in 175 [I-D.ietf-ospf-prefix-link-attr]. The flooding scope of the 176 Extended Prefix Opaque LSA type will be set to area-scope. The 177 route-type in the OSPF Extended Prefix TLV is set to inter-area. 178 When determining whether a BIER MPLS Sub-TLV should be included in 179 this LSA ABR will: 181 - look at its best path to the prefix in the source area and 182 find the advertising router associated with the best path to 183 that prefix. 185 - determine if such advertising router advertised a BIER MPLS 186 Sub-TLV for the prefix. If yes, ABR will copy the information 187 from such BIER MPLS Sub-TLV when advertising BIER MPLS Sub-TLV 188 to each connected area. 190 3. Security Considerations 192 Implementations must assure that malformed TLV and Sub-TLV 193 permutations do not result in errors which cause hard OSPF failures. 195 4. IANA Considerations 197 The document requests one new allocation from the OSPF Extended 198 Prefix sub-TLV registry as defined in 199 [I-D.ietf-ospf-prefix-link-attr]. 201 BIER MPLS Sub-TLV: TBD 203 5. Acknowledgments 205 The authors would like to thank Rajiv Asati, Christian Martin, Greg 206 Shepherd and Eric Rosen for their contribution. 208 6. Normative References 210 [I-D.ietf-ospf-prefix-link-attr] 211 Psenak, P., Gredler, H., Shakir, R., Henderickx, W., 212 Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute 213 Advertisement", draft-ietf-ospf-prefix-link-attr-01 (work 214 in progress), September 2014. 216 [I-D.wijnands-bier-architecture] 217 Wijnands, I., Rosen, E., Dolganow, A., and T. Przygienda, 218 "Multicast using Bit Index Explicit Replication", draft- 219 wijnands-bier-architecture-00 (work in progress), 220 September 2014. 222 [I-D.wijnands-mpls-bier-encapsulation] 223 Wijnands, I., Rosen, E., Dolganow, A., and J. Tantsura, 224 "Encapsulation for Bit Index Explicit Replication in MPLS 225 Networks", draft-wijnands-mpls-bier-encapsulation-00 (work 226 in progress), September 2014. 228 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 229 Requirement Levels", BCP 14, RFC 2119, March 1997. 231 [RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P. 232 Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF", RFC 233 4915, June 2007. 235 Authors' Addresses 237 Peter Psenak (editor) 238 Cisco 239 Apollo Business Center 240 Mlynske nivy 43 241 Bratislava 821 09 242 Slovakia 244 Email: ppsenak@cisco.com 246 Nagendra Kumar 247 Cisco 248 7200 Kit Creek Road 249 Research Triangle Park, NC 27709 250 US 252 Email: naikumar@cisco.com 254 IJsbrand Wijnands 255 Cisco 256 De Kleetlaan 6a 257 Diegem 1831 258 Belgium 260 Email: ice@cisco.com 262 Andrew Dolganow 263 Alcatel-Lucent 264 600 March Rd. 265 Ottawa, Ontario K2K 2E6 266 Canada 268 Email: andrew.dolganow@alcatel-lucent.com