idnits 2.17.1 draft-ietf-pim-join-attributes-01.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** It looks like you're using RFC 3978 boilerplate. You should update this to the boilerplate described in the IETF Trust License Policy document (see https://trustee.ietf.org/license-info), which is required now. -- Found old boilerplate from RFC 3978, Section 5.1 on line 16. -- Found old boilerplate from RFC 3978, Section 5.5 on line 318. -- Found old boilerplate from RFC 3979, Section 5, paragraph 1 on line 295. -- Found old boilerplate from RFC 3979, Section 5, paragraph 2 on line 302. -- Found old boilerplate from RFC 3979, Section 5, paragraph 3 on line 308. ** This document has an original RFC 3978 Section 5.4 Copyright Line, instead of the newer IETF Trust Copyright according to RFC 4748. ** This document has an original RFC 3978 Section 5.5 Disclaimer, instead of the newer disclaimer which includes the IETF Trust according to RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- == No 'Intended status' indicated for this document; assuming Proposed Standard Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack a both a reference to RFC 2119 and the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords. RFC 2119 keyword, line 103: '... router MUST forward the TLV upstrea...' RFC 2119 keyword, line 104: '...his bit is not set the router MUST NOT...' RFC 2119 keyword, line 179: '... processed MUST be passed upstream u...' Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date () is 739377 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: 'R1' is mentioned on line 132, but not defined == Missing Reference: 'S' is mentioned on line 135, but not defined == Missing Reference: 'R2' is mentioned on line 138, but not defined == Outdated reference: A later version (-12) exists of draft-ietf-pim-sm-v2-new-11 Summary: 4 errors (**), 0 flaws (~~), 6 warnings (==), 7 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 PIM WG A. Boers 3 Internet-Draft IJ. Wijnands 4 Expires: September 2, 2006 E. Rosen 5 Cisco Systems, Inc. 6 march 2006 8 Format for using TLVs in PIM messages 9 draft-ietf-pim-join-attributes-01 11 Status of this Memo 13 By submitting this Internet-Draft, each author represents that any 14 applicable patent or other IPR claims of which he or she is aware 15 have been or will be disclosed, and any of which he or she becomes 16 aware will be disclosed, in accordance with Section 6 of BCP 79. 18 Internet-Drafts are working documents of the Internet Engineering 19 Task Force (IETF), its areas, and its working groups. Note that 20 other groups may also distribute working documents as Internet- 21 Drafts. 23 Internet-Drafts are draft documents valid for a maximum of six months 24 and may be updated, replaced, or obsoleted by other documents at any 25 time. It is inappropriate to use Internet-Drafts as reference 26 material or to cite them other than as "work in progress." 28 The list of current Internet-Drafts can be accessed at 29 http://www.ietf.org/ietf/1id-abstracts.txt. 31 The list of Internet-Draft Shadow Directories can be accessed at 32 http://www.ietf.org/shadow.html. 34 This Internet-Draft will expire on September 2, 2006. 36 Copyright Notice 38 Copyright (C) The Internet Society (2006). 40 Abstract 42 This document describes a generic TLV attribute encoding format to be 43 added to PIM join messages. 45 Table of Contents 47 1. Conventions used in this document . . . . . . . . . . . . . . . 3 48 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 49 3. Use of the Attribute Field in Join Messages . . . . . . . . . . 3 50 3.1. Attribute join . . . . . . . . . . . . . . . . . . . . . . 3 51 3.2. Transitive attributes . . . . . . . . . . . . . . . . . . . 3 52 3.3. Attribute Hello Option . . . . . . . . . . . . . . . . . . 3 53 3.4. Conflicting attributes . . . . . . . . . . . . . . . . . . 4 54 3.5. Attribute Convergence . . . . . . . . . . . . . . . . . . . 4 55 3.6. Multiple attributes . . . . . . . . . . . . . . . . . . . . 5 56 3.7. Applicability of the attributes . . . . . . . . . . . . . . 5 57 3.8. PIM attribute packet format . . . . . . . . . . . . . . . . 5 58 3.8.1. PIM Join packet format . . . . . . . . . . . . . . . . 5 59 3.8.2. PIM Attribute Hello option . . . . . . . . . . . . . . 6 60 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 61 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 62 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 6 63 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 64 7.1. Normative References . . . . . . . . . . . . . . . . . . . 7 65 7.2. Informative References . . . . . . . . . . . . . . . . . . 7 66 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 67 Intellectual Property and Copyright Statements . . . . . . . . . . 9 69 1. Conventions used in this document 71 In this document, the key words "MUST", "MUST NOT", "REQUIRED", 72 "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", 73 and "OPTIONAL" are to be interpreted as described in RFC 2119 and 74 indicate requirement levels for compliant PIM-SM implementations. 76 2. Introduction 78 It is sometimes convenient to add additional information to PIM join 79 messages. The generic PIM encoding format is not always optimal to 80 do this. This document defines a new field in the PIM Join message 81 that allows it to use TLVs, hereby called the attribute field. The 82 content and purpose of this attribute field is outside the scope of 83 this document, only the generic encoding format is described here. 85 3. Use of the Attribute Field in Join Messages 87 3.1. Attribute join 89 Attribute fields are defined similar to the PIM source encoding type 90 as defined in [I-D.ietf-pim-sm-v2-new]. A source address without any 91 additional TLV's should be processed identically to a source address 92 in the default source encoding. 94 Multiple TLV's from the same or different type are permitted in a 95 single source address in any order. 97 3.2. Transitive attributes 99 It may be desired to have routers that understand the generic 100 attribute format, forward the attributes regardless of whether they 101 understand the TLV's encoded in the attribute not. For this the 102 first bit in the Type field is reserved. If this bit is set then the 103 router MUST forward the TLV upstream in case the router does not 104 understand that type. If this bit is not set the router MUST NOT 105 forward the TLV upstream in the case the router does not understand 106 that type. 108 3.3. Attribute Hello Option 110 A new PIM source type has been defined to include the Attribute 111 field. This source type is included in a normal PIM Join. Each 112 router on a connected network needs to be able to understand and 113 parse the Join message. Therefore we include a new PIM hello option 114 to advertise our capability to parse and process the new source type. 116 We can only send a PIM Join which includes an attribute if ALL 117 routers on the network support the new option. (Even a router which 118 is not the upstream neighbor must be able parse to the packet in 119 order to do Join suppression or overriding.) Option value TBD. 121 Having the attribute hello option does not guarantee that all 122 neighbors understand all possible individual attributes. As there's 123 no immediate way to act on a neighbor's incapability to process 124 certain attribute types, it is not desired to have a hello option for 125 each possible attribute type. 127 3.4. Conflicting attributes 129 It's possible that a router receives conflicting attribute 130 information from different downstream routers. See Figure 2. 132 ( Edge A1 ) ( Edge B1 )---- [R1] 133 / \ / 134 / \ / 135 [S] ( Core ) 136 \ / \ 137 \ / \ 138 ( Edge A2 ) ( Edge B2 )---- [R2] 140 Figure 2 142 An example join attribute in this case is an exit router. There are 143 2 receivers for the same group connected to Edge B1 and B2. Suppose 144 that edge router B1 prefers A1 as the exit point and B2 prefers A2 as 145 exit point to reach the source S. If both Edge B1 and B2 send a Join 146 including an attribute to prefer their exit router in the network and 147 they cross the same core router, the core router will get conflicting 148 attribute information for the source. If this happens we use the 149 Attribute from the PIM adjacency with the numerically smallest IP 150 address. The attributes from other sending routers may be kept 151 around in case the best attribute gets pruned or expires, we are able 152 to immediately use the second best attribute and converge quickly 153 without waiting for the next periodic update. If a TLV has its own 154 definition for conflict resolution it is preferred over the conflict 155 resolution above. 157 3.5. Attribute Convergence 159 An attribute is included in a PIM Join message together with the 160 source information. If the attribute for this source is changed, we 161 trigger a new PIM Join message to the upstream router. This causes 162 the new attribute to be propagated. This new attribute implicitly 163 removes the old attribute upstream. If processing the new attribute 164 results in a change in the distribution tree, a PIM Prune message may 165 be sent. This PIM Prune does not need to carry any attribute, the 166 sender of the prune and the source and group information is enough to 167 identify the entry. The attribute information is removed immediately 168 and possibly a new attribute is chosen from the database if 169 available. 171 3.6. Multiple attributes 173 A PIM Join can contain multiple attributes. The attributes are 174 encoded as TLVs associated with a new PIM source type in the PIM 175 message. When a PIM Join with multiple attributes is received, the 176 first attribute is processed, and the action taken depends upon the 177 attribute type. This may or may not result in the processing of the 178 next attribute. Attributes that the router understands but are not 179 processed MUST be passed upstream unchanged. 181 3.7. Applicability of the attributes 183 PIM Joins with attributes can be applied to both shared-trees rooted 184 at a Rendezvous Point (RP) and shortest-path trees as described in 185 [I-D.ietf-pim-sm-v2-new]. 187 3.8. PIM attribute packet format 189 3.8.1. PIM Join packet format 191 There is no space in the default PIM source encoding to include a 192 attribute field. Therefore we introduce a new source encoding type. 193 The attributes are formatted as TLV's. The new Encoded source 194 address looks like this: 196 0 1 2 3 197 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 1 198 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 199 | Addr Family | Encoding Type | Rsrvd |S|W|R| Mask Len | 200 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 201 | Source Address (Encoded-Source format) | 202 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 203 |F|S| Type | Length | Value 204 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+..... 205 |F|S| Type | Length | Value 206 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+..... 207 . . . 208 . . . 210 F bit, Forward Unknown TLV. If this bit is set the TLV is forwarded 211 regardless if the router understands the Type. 213 S bit, Bottom of Stack. If this bit is set then this is the last TLV 214 in the stack. 216 Type field of the TLV is 6 bits. 218 Length field of the TLV is 1 byte. 220 The other fields are the same as described in the PIM spec. 221 [I-D.ietf-pim-sm-v2-new]. 223 The source TLV encoding type: TBD. 225 3.8.2. PIM Attribute Hello option 227 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 1 228 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 229 | OptionType = TBD | OptionLength = 0 | 230 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 232 Option type: TBD. 234 4. IANA Considerations 236 This document requires a new PIM Hello Option value and a new PIM 237 Join Encoding type. 239 5. Security Considerations 241 Security of the join attribute is only guaranteed by the security of 242 the PIM packet, so the security considerations for PIM join packets 243 as described in PIM-SM [I-D.ietf-pim-sm-v2-new] apply here. 245 6. Acknowledgments 247 The authors would like to thank James Lingard, Bharat Joshi, Marshall 248 Eubanks, Stig Venaas, Pekka Savola and Tom Pusateri for their input. 250 7. References 251 7.1. Normative References 253 [I-D.ietf-pim-sm-v2-new] 254 Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas, 255 "Protocol Independent Multicast - Sparse Mode PIM-SM): 256 Protocol Specification (Revised)", 257 draft-ietf-pim-sm-v2-new-11 (work in progress), 258 October 2004. 260 7.2. Informative References 261 Authors' Addresses 263 Arjen Boers 264 Cisco Systems, Inc. 265 Avda. Diagonal, 682 266 Barcelona 08034 267 Spain 269 Email: aboers@cisco.com 271 IJsbrand Wijnands 272 Cisco Systems, Inc. 273 De kleetlaan 6a 274 Diegem 1831 275 Belgium 277 Email: ice@cisco.com 279 Eric Rosen 280 Cisco Systems, Inc. 281 1414 Massachusetts Avenue 282 Boxborough, Ma 01719 284 Email: erosen@cisco.com 286 Intellectual Property Statement 288 The IETF takes no position regarding the validity or scope of any 289 Intellectual Property Rights or other rights that might be claimed to 290 pertain to the implementation or use of the technology described in 291 this document or the extent to which any license under such rights 292 might or might not be available; nor does it represent that it has 293 made any independent effort to identify any such rights. Information 294 on the procedures with respect to rights in RFC documents can be 295 found in BCP 78 and BCP 79. 297 Copies of IPR disclosures made to the IETF Secretariat and any 298 assurances of licenses to be made available, or the result of an 299 attempt made to obtain a general license or permission for the use of 300 such proprietary rights by implementers or users of this 301 specification can be obtained from the IETF on-line IPR repository at 302 http://www.ietf.org/ipr. 304 The IETF invites any interested party to bring to its attention any 305 copyrights, patents or patent applications, or other proprietary 306 rights that may cover technology that may be required to implement 307 this standard. Please address the information to the IETF at 308 ietf-ipr@ietf.org. 310 Disclaimer of Validity 312 This document and the information contained herein are provided on an 313 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 314 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET 315 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, 316 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE 317 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 318 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 320 Copyright Statement 322 Copyright (C) The Internet Society (2006). This document is subject 323 to the rights, licenses and restrictions contained in BCP 78, and 324 except as set forth therein, the authors retain all their rights. 326 Acknowledgment 328 Funding for the RFC Editor function is currently provided by the 329 Internet Society.