idnits 2.17.1 draft-ietf-ipv6-link-scoped-mcast-02.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** Looks like you're using RFC 2026 boilerplate. This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- ** The document seems to lack a 1id_guidelines paragraph about Internet-Drafts being working documents -- however, there's a paragraph with a matching beginning. Boilerplate error? ** The document seems to lack a 1id_guidelines paragraph about 6 months document validity -- however, there's a paragraph with a matching beginning. Boilerplate error? == No 'Intended status' indicated for this document; assuming Proposed Standard == The page length should not exceed 58 lines per page, but there was 6 longer pages, the longest (page 1) being 61 lines Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) ** The document seems to lack separate sections for Informative/Normative References. All references will be assumed normative when checking for downward references. ** There are 10 instances of too long lines in the document, the longest one being 5 characters in excess of 72. == There are 1 instance of lines with non-RFC3849-compliant IPv6 addresses in the document. If these are example addresses, they should be changed. Miscellaneous warnings: ---------------------------------------------------------------------------- == The "Author's Address" (or "Authors' Addresses") section title is misspelled. -- 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 (October 2002) is 7835 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: 'RFC 2119' is mentioned on line 87, but not defined == Missing Reference: 'RFC3041' is mentioned on line 196, but not defined ** Obsolete undefined reference: RFC 3041 (Obsoleted by RFC 4941) == Unused Reference: 'RFC 2373' is defined on line 206, but no explicit reference was found in the text == Unused Reference: 'RFC 3041' is defined on line 223, but no explicit reference was found in the text ** Obsolete normative reference: RFC 2373 (Obsoleted by RFC 3513) ** Obsolete normative reference: RFC 2461 (Obsoleted by RFC 4861) ** Obsolete normative reference: RFC 2908 (Obsoleted by RFC 6308) ** Downref: Normative reference to an Historic RFC: RFC 2909 ** Obsolete normative reference: RFC 3041 (Obsoleted by RFC 4941) -- Possible downref: Non-RFC (?) normative reference: ref. 'AAP WORK' -- Possible downref: Non-RFC (?) normative reference: ref. 'ADDRARCH' -- Possible downref: Non-RFC (?) normative reference: ref. 'UNIMULTI' -- Possible downref: Non-RFC (?) normative reference: ref. 'IPV6 GID' -- Possible downref: Non-RFC (?) normative reference: ref. 'SSM ARCH' Summary: 12 errors (**), 0 flaws (~~), 8 warnings (==), 7 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 INTERNET DRAFT Jung-Soo Park 3 Expires: April 2003 Myung-Ki Shin 4 ETRI 5 October 2002 7 Link Scoped IPv6 Multicast Addresses 8 10 Status of this Memo 12 This document is an Internet-Draft and is in full conformance with 13 all provisions of Section 10 of RFC2026. 15 Internet-Drafts are working documents of the Internet Engineering 16 Task Force (IETF), its areas, and working groups. Note that other 17 groups may also distribute working documents as Internet-Drafts. 19 Internet-Drafts are draft documents valid for a maximum of six 20 months and may be updated, replaced, or made obsolete by other documents 21 at anytime. It is inappropriate to use Internet-Drafts as reference 22 material or to cite them other than as "works in progress." 24 The list of current Internet-Drafts can be accessed at 25 http://www.ietf.org/ietf/1id-abstracts.txt. 27 The list of Internet-Draft Shadow Directories can be accessed at 28 http://www.ietf.org/shadow.html. 30 Abstract 32 This document specifies an extension to the multicast addressing 33 architecture of the IPv6 protocol. The extension allows for the 34 use of interface-IDs to allocate multicast addresses. When the 35 link-local unicast address is configured at each interface of a host, 36 an interface ID is uniquely determined. By delegating multicast 37 addresses at the same time as the interface ID, each host can identify 38 their multicast addresses automatically at Layer 1 without running 39 an intra- or inter-domain allocation protocol in serverless 40 environments. 42 Table of Contents: 44 1. Introduction 45 2. Terminology 46 3. Applicability 47 4. Link scoped multicast address format 48 5. Source-specific multicast addresses 49 6. Examples 50 7. Considerations 51 8. Security considerations 52 9. References 53 10. Acknowledgements 55 1. Introduction 57 This specification defines an extension to the multicast portion of 58 the IPv6 addressing architecture [ADDRARCH]. The current 59 architecture does not contain any built-in support for dynamic 60 address allocation. The extension allows for use of interface-IDs to 61 allocate multicast addresses. When the link-local unicast address 62 is configured at each interface of a host, an interface ID is uniquely 63 determined. By delegating multicast addresses at the same time as 64 the interface ID, each host can identify its multicast addresses 65 automatically without running an intra- or inter-domain allocation 66 protocol in serveless environments. 68 The current multicast address allocation architecture [RFC 2908] is 69 based on a multi-layered, multi-protocol system. The goal of this 70 proposal is to reduce the number of protocols and servers to get 71 dynamic multicast address allocation. 73 The use of interface ID-based multicast address allocation will, at 74 a minimum, remove the need to run the Multicast Address Allocation 75 Protocol (AAP) [AAP WORK][RFC 2909] and the Multicast Address 76 Allocation servers [RFC 2908]. 78 This document specifies encoded information in the link scoped 79 multicast address to allow for dynamic allocation of IPv6 multicast 80 addresses. 82 2. Terminology 84 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 85 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in 86 this document are to be interpreted as described in [RFC 2119]. 88 3. Applicability 89 The allocation technique in this document is designed to be used in 90 any environment in which link-local scope IPv6 multicast addresses 91 are assigned or selected. Especially, this method goes well with 92 nodes supplying multicast services in a zeroconf environment. For 93 example, multicast addresses less than or equal to link-local scope 94 are themselves generated by nodes supplying multicast services. 96 Consequently, this technique is limited to use by multicast scope. 97 If you want to use multicast addresses greater than link-local, you 98 need other methods. 100 4. Link scoped multicast address format 102 Section 2.7 of [ADDRARCH] defines the following operational format 103 of IPv6 multicast addresses: 105 | 8 | 4 | 4 | 112 | 106 +--------+----+----+---------------------------------------------+ 107 |11111111|flgs|scop| group ID | 108 +--------+----+----+---------------------------------------------+ 110 Figure 1: Generic IPv6 multicast address format 112 This document introduces new formats that incorporate interface ID 113 information in the multicast address. The idea of delegating 114 multicast addresses at the same time as the interface ID, can be 115 applicable to link-local. 117 Figure 2 illustrates the new format for link-local multicast 118 addresses. 120 | 8 | 4 | 4 | 16 | 64 | 32 | 121 +--------+----+----+------------+----------------+---------------+ 122 |11111111|flgs|scop| reserved | Interface ID | group ID | 123 +--------+----+----+------------+----------------+---------------+ 125 Figure 2: link scoped multicast address format 127 +-+-+-+-+ 128 flgs is a set of 4 flags: |0|0|P|T| 129 +-+-+-+-+ 131 o P = 0 indicates a multicast address that is not assigned 132 on the basis of the interface ID. 133 o P = 1 indicates a multicast address that is assigned 134 on the basis of the interface ID. 135 o If P = 1, T MUST be set to 1, otherwise the setting of 136 the T bit is defined in Section 2.7 of RFC 2373. 138 flgs should use the same flag defined in section 3 of [UNIMULTI]. 139 That is, this document proposes the third bit of 'flgs' field to 140 indicates an Interface ID-based multicast addresses. Additionally, 141 it is necessary to distinguish between an Inteface ID-based multicast 142 address and a unicast-prefix-based multicast address. 144 scop <= 2. The scope of this multicast address MUST be independent 145 of the scope of the unicast address, which derives the interface ID 146 embedded in the multicast address. 148 The reserved field MUST be zero. 150 interface ID field is used to distinguish each host from others. 151 And this value is obtained from the IEEE EUI-64 based interface 152 identifier of the link-local unicast IPv6 address. 154 group ID is generated to indicate multicast application and is used 155 to guarantee its uniqueness only in the host. It may also be set on 156 the basis of the guidelines outlined in [IPV6 GID]. 158 The lifetime of an Interface ID-based multicast address has no 159 dependency on the Valid Lifetime field in the Prefix Information 160 option, corresponding to the unicast address being used, contained 161 in the Router Advertisement message [RFC 2461]. 163 5. Source-specific multicast addresses 165 The link scoped multicast address format supports source-specific 166 multicast addresses, as defined by [SSM ARCH]. To accomplish this, 167 a node MUST: 169 o Set P = 1. 170 o Set interface ID = 0. 172 These settings create an SSM range of FF32::/96. The source address 173 field in the IPv6 header identifies the owner of the multicast 174 address. 176 6. Examples 178 This is an example of an interface ID-based multicast address with 179 link-local scope. For example in an ethernet environment, if the 180 link-local unicast address is FE80::12:34:56:78:90:AB, 181 the mutlicast prefix of the host is FF32:0:1234:56FF:FE78:90AB::/96. 182 For SSM, multicast adrress will be FF32::/96. 184 7. Considerations 186 This draft considers only link-local multicast addresses. For 187 this purpose, P flag is used in figure 2. The [UNIMULTI] draft also 188 uses the P flag to indicate a multicast address that is assigned on 189 the basis of the network prefix. For consistency, some modifications 190 in the [UNIMULTI] draft are required. For example, by restrictng the 191 syntax to scope > 2 in [UNIMULTI]. 193 8. Security considerations 195 [RFC3041] describes the privacy extension to IPv6 stateless 196 address autoconfiguration for an interface ID. So, [RFC3041] 197 satisfied our requirements. 199 Using source-specific multicast addresses can sometimes aid in the 200 prevention of denial-of-service attacks by arbitrary sources, 201 although no guarantee is provided. A more in-depth discussion of 202 the security considerations for SSM can be found in [SSM ARCH]. 204 9. References 206 [RFC 2373] 207 R. Hinden and S. Deering, "IP Version 6 Addressing Architecture", 208 RFC 2373, October 1998. 210 [RFC 2461] 211 Narten, T., Nordmark, E., Simpson, W., "Neighbor Discovery for IP 212 Version 6 (IPv6)", RFC 2461, December 1998. 214 [RFC 2908] 215 D. Thaler, M. Handley and D. Estrin, "Th Internet Multicast Address 216 Allocation Architecture," RFC2908, September 2000. 218 [RFC 2909] 219 Radoslavov, P., Estrin, D., Govindan, R., Handley, M., Kumar, S. 220 and D. Thaler, "The Multicast Address-Set Claim (MASC) Protocol", 221 RFC 2909, September 2000. 223 [RFC 3041] 224 T. Narten and R. Draves, "Privacy Extensions for Stateless Address 225 Autoconfiguration in IPv6," RFC 3041, April 2001. 227 [AAP WORK] 228 Handley, M. and S. Hanna, "Multicast Address Allocation Protocol 229 (AAP)", Work in Progress. 231 [ADDRARCH] 232 R. Hinden and S. Deering, "IP Version 6 Addressing Architecture", 233 Work In Progress, October 2001. 235 [UNIMULTI] 236 B. Haberman and D. Thaler, "Unicast-Prefix-based IPv6 Multicast 237 Addresses," Work In Progress, December 2001. 239 [IPV6 GID] 240 B. Haberman, "Dynamic Allocation Guidelines for IPv6 Multicast 241 Addresses," Work In Progress, October 2001. 243 [SSM ARCH] 244 H. Holbrook and B. Cain, "Source-Specific Multicast for IP", 245 Work In Progress, March 2001. 247 10. Acknowledgements 249 We would like to thank Dave Thaler for his comments related to the 250 consistency between the unicast prefix-based multicast draft and 251 this one. 253 Authors Addresses 255 Jung-Soo Park 256 ETRI PEC 257 161 Kajong-Dong, Yusong-Gu, Taejon 305-600, Korea 258 Tel : +82 42 860 6514 259 Fax : +82 42 861 5404 260 E-mail : jspark@pec.etri.re.kr 262 Myung-Ki Shin 263 ETRI PEC 264 161 Kajong-Dong, Yusong-Gu, Taejon 305-600, Korea 265 Tel : +82 42 860 4847 266 Fax : +82 42 861 5404 267 E-mail : mkshin@pec.etri.re.kr