Internet Engineering Task Force P. Savola Internet-Draft CSC/FUNET Obsoletes:
2776,2908,2909 October 16, 20062908 (if approved) August 3, 2009 Intended status: Best Current PracticeInformational Expires: April 19, 2007February 4, 2010 Overview of the Internet Multicast Addressing Architecture draft-ietf-mboned-addrarch-05.txtdraft-ietf-mboned-addrarch-06.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or sheThis Internet-Draft is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed,submitted to IETF in accordancefull conformance with Section 6the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 19, 2007.February 4, 2010. Copyright Notice Copyright (C) The Internet Society (2006).(c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract The lack of up-to-date documentation on IP multicast address allocation and assignment procedures has caused a great deal of confusion. To clarify the situation, this memo describes the allocation and assignment techniques and mechanisms currently (as of this writing) in use. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology: Allocation or Assignment . . . . . . . . . . 3 2. Multicast Address Allocation . . . . . . . . . . . . . . . . . 4 2.1. Derived Allocation . . . . . . . . . . . . . . . . . . . . 4 2.1.1. GLOP Allocation . . . . . . . . . . . . . . . . . . . 4 2.1.2. Unicast-prefix -basedUnicast-prefix-based Allocation . . . . . . . . . . . 4 2.2. Administratively Scoped Allocation . . . . . . . . . . . . 5 2.3. Static IANA Allocation . . . . . . . . . . . . . . . . . . 6 2.4. Dynamic Allocation . . . . . . . . . . . . . . . . . . . . 6 3. Multicast Address Assignment . . . . . . . . . . . . . . . . . 67 3.1. Derived Assignment . . . . . . . . . . . . . . . . . . . . 7 3.2. SSM Assignment inside the Node . . . . . . . . . . . . . . 7 3.3. Manually Configured Assignment . . . . . . . . . . . . . . 7 3.4. Static IANA Assignment . . . . . . . . . . . . . . . . . . 8 3.4.1. Global IANA Assignment . . . . . . . . . . . . . . . . 8 3.4.2. Scope-relative IANA Assignment . . . . . . . . . . . . 8 3.5. Dynamic Assignments . . . . . . . . . . . . . . . . . . . 98 4. Summary and Future Directions . . . . . . . . . . . . . . . . 109 4.1. Prefix Allocation . . . . . . . . . . . . . . . . . . . . 10 4.2. Address Assignment . . . . . . . . . . . . . . . . . . . . 11 4.3. Future Actions . . . . . . . . . . . . . . . . . . . . . . 11 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 8.1. Normative References . . . . . . . . . . . . . . . . . . . 13 8.2. Informative References . . . . . . . . . . . . . . . . . . 13 Appendix A. Changes . . . . . . . . . . . . . . . . . . . . . . . 15 A.1. Changes between -04 and-05 and -06 . . . . . . . . . . . . . . . 15 A.2. Changes between -03 and-04 and -05 . . . . . . . . . . . . . . . 1615 A.3. Changes between -02 and-03 and -04 . . . . . . . . . . . . . . . 16 A.4. Changes between -01 and-02 and -03 . . . . . . . . . . . . . . . 16 Author's AddressA.5. Changes between -01 and -02 . . . . . . . . . . . . . . . 16 Author's Address . . . . . . . . . . . . 16 Intellectual Property and Copyright Statements. . . . . . . . . . 17. . . 16 1. Introduction Good, up-to-date documentation of IP multicast is close to non- existent. Particularly, this is an issue with multicast address allocations (to networks and sites) and assignments (to hosts and applications). This problem is stressed by the fact that there exists confusing or misleading documentation on the subject [RFC2908]. The consequence is that those who wish to learn about IP multicast and how the addressing works do not get a clear view of the current situation. The aim of this document is to provide a brief overview of multicast addressing and allocation techniques. The term 'addressing architecture' refers to the set of addressing mechanisms and methods in an informal manner. It is important to note that Source-specific Multicast (SSM) [RFC4607] does not have these addressing problems because SSM group addresses have only local significance; hence, this document focuses on the Any Source Multicast (ASM) model. This memo obsoletes RFCs 2776,and re-classifies to Historic RFC 2908, and 2909re- classifies to Historic RFCs 2776 and re-classifies them Historic.2909. 1.1. Terminology: Allocation or Assignment Almost all multicast documents and many other RFCs (such as DHCPv4 [RFC2131] and DHCPv6 [RFC3315]) have used the terms address "allocation" and "assignment" interchangeably. However, the operator and address management communities use these terms for two conceptually different processes. In unicast operations, address allocations refer to leasing a large block of addresses from Internet Assigned Numbers Authority (IANA) to a Regional Internet Registry (RIR) or from RIR to a Local Internet Registry (LIR) possibly through a National Internet Registry (NIR). Address assignments, on the other hand, are the leases of smaller address blocks or even single addresses to the end-user sites or end- users themselves. Therefore, in this memo, we will separate the two different functions: "allocation" describes how larger blocks of addresses are obtained by the network operators, and "assignment" describes how applications, nodes or sets of nodes obtain a multicast address for their use. 2. Multicast Address Allocation Multicast address allocation, i.e., how a network operator might be able to obtain a larger block of addresses, can be handled in a number of ways as described below. Note that these are all only pertinent to ASM -- SSM requires no address block allocation because the group address has only local significance (however, we discuss the address assignment inside the node in Section 3.2). 2.1. Derived Allocation Derived allocations take the unicast prefix or some other properties of the network (e.g., an autonomous system (AS) number) to determine unique multicast address allocations. 2.1.1. GLOP Allocation GLOP address allocation [RFC3180] inserts the 16-bit public AS number in the middle of the IPv4 multicast prefix 220.127.116.11/8, so that each AS number can get a /24 worth of multicast addresses. While this is sufficient for multicast testing or small scale use, it might not be sufficient in all cases for extensive multicast use. A minor operational debugging issue with GLOP addresses is that the connection between the AS and the prefix is not apparent from the prefix when the AS number is greater than 255, but has to be calculated (e.g., from [RFC3180], AS 5662 maps to 18.104.22.168/24). A usage issue is that GLOP addresses are not tied to any prefix but to routing domains, so they cannot be used or calculated automatically. GLOP mapping is not available with 4-byte AS numbers [RFC4893]. Unicast-prefix-based Allocation or an IANA allocation from "AD-HOC Block III" (the previous so-called "eGLOP" block) could be used instead as needed. The GLOP allocation algorithm has not been defined for IPv6 multicast because the unicast-prefix -basedunicast-prefix-based allocation (described below) addresses the same need in a simpler fashion. GLOP hasn't been (and likely never will be) specified for 4-byte AS numbers [I-D.ietf-idr-as4bytes].2.1.2. Unicast-prefix -basedUnicast-prefix-based Allocation RFC 3306 [RFC3306] describes a mechanism which embeds up to 64 high- order bits of an IPv6 unicast address in the prefix part of the IPv6 multicast address, leaving at least 32 bits of group-id space available after the prefix mapping. A similar mapping has been proposed forIPv4 mapping is described in [I-D.ietf-mboned-ipv4-uni-based-mcast], but it provides a rather low amountlimited number of addresses (e.g., 1 per an IPv4 /24 block). Although large networks without an AS number do exist, this technique has not been seen to add value compared to GLOP addressing.The IPv6 unicast-prefix-based allocations are an extremely useful way to allow each network operator, even each subnet, to obtain multicast addresses easily, through an easy computation. Further, as the IPv6 multicast header also includes the scope value [RFC3513],[RFC4291], multicast groups of smaller scope can also be used with the same mapping. The IPv6 Embedded RP technique [RFC3956], used with Protocol Independent Multicast - Sparse Mode (PIM-SM), further leverages the unicast prefix basedunicast-prefix-based allocations, by embedding the unicast prefix and interface identifier of the PIM-SM Rendezvous Point (RP) in the prefix. This provides all the necessary information needed to the routing systems to run the group in either inter- or intra-domain operation. A difference from RFC 3306 is, however, that the hosts cannot calculate their "multicast prefix" automatically, as the prefix depends on the decisions of the operator setting up the RP, but instead requires an assignment method. All the IPv6 unicast-prefix-based allocation techniques provide sufficient amount of multicast address space for thenetwork operators. 2.2. Administratively Scoped Allocation Administratively scoped multicast address allocation [RFC2365] is provided by two different means: under 22.214.171.124/8 in IPv4 or by 4-bit encoding in the IPv6 multicast address prefix [RFC3513].[RFC4291]. Since IPv6 administratively scoped allocations can be handled with unicast-prefix-based multicast addressing as described in Section 2.1.2, we'll justonly discuss IPv4 in this section. The IPv4 administratively scoped prefix 126.96.36.199/8 is further divided tointo Local Scope (188.8.131.52/16) and Organization Local Scope (184.108.40.206/14); other parts of the administrative scopes are either reserved for expansion or undefined [RFC2365]. However, RFC 2365 is ambiguous as to whether the enterprises or the IETF are allowed to expand the space. Topologies which act under a single administration can easily use the scoped multicast addresses for their internal groups. Groups which need to be shared between multiple routing domains (even if not propagated through the Internet) are more problematic and typically need an assignment of a global multicast address because their scope is undefined. There is a large number of multicast applications (such as "Norton Ghost") which are restricted either to a link or a site, and it is extremely undesirable to propagate them further (beyond the link or the site). Typically many such applications have been given or have hijacked a static IANA address assignment. TheGiven the fact that assignments to typically locally used applications come from the same range as global applications, implementing proper propagation limiting is challenging. Filtering would be easier if such applicationsa separate, identifiable range would in futurebe assigned specific administratively scoped addresses instead. Thisused for such assignments in the future; this is an area of further future work. There has also been work on a protocol to automatically discover multicast scope zones [RFC2776], but it has never been widely implemented or deployed. 2.3. Static IANA Allocation In some rare cases, someorganizations may have been able to obtain static multicast address allocations (of up to 256 addresses) directly from IANA. Typically these have been meant as a block of static assignments to multicast applications, as described in Section 3.4.1. In principle, IANA should not and does not allocate multicast address blocks to the operators but GLOP or Unicast-prefix- based allocations should be used instead.If another means of obtaining addresses is available that approach is preferable. Especially for those operators that only have a 32-bit AS number and need IPv4 addresses, an IANA allocation from "AD-HOC Block III" (the previous so-called "eGLOP" block) is an option [I-D.ietf-mboned-rfc3171bis]. 2.4. Dynamic Allocation RFC 2908 [RFC2908] proposed three different layers of multicast address allocation and assignment, where layers 3 (inter-domain allocation) and layer 2 (intra-domain allocation) could be applicable here. Multicast Address-Set Claim Protocol (MASC) [RFC2909] is an example of the former, and Multicast Address Allocation Protocol (AAP) [I-D.ietf-malloc-aap] (abandoned in 2000 due lack of interest and technical problems) is an example of the latter. Both of the proposed allocation protocols were quite complex, and have never been deployed or seriously implemented. It can be concluded that dynamic multicast address allocation protocols provide no benefit beyond GLOP/unicast-prefix-based mechanisms and have been abandoned. 3. Multicast Address Assignment There are a number of possible ways for an application, node or set of nodes to learn a multicast address as described below. Any IPv6 address assignment method should be aware of the guidelines for the assignment of thegroup-IDs for IPv6 multicast addresses [RFC3307]. 3.1. Derived Assignment There are significantly fewer options for derived address assignment compared to derived allocation. Derived multicast assignment has only been specified for IPv6 link-scoped multicast [RFC4489], where the EUI64 is embedded in the multicast address, providing a node with unique multicast addresses for link-local ASM communications. 3.2. SSM Assignment inside the Node While theSSM multicast addresses have only local (to the node) significance, there is still a minor issue on how to assign the addresses between the applications running on the same IP address. This assignment is not considered to be a problem because typically the addresses for thethese applications are selected manually or statically, but if done using an Application Programming Interface (API), the API could check that the addresses do not conflict prior to assigning one. 3.3. Manually Configured Assignment With manually configured assignment, thea network operator who has a multicast address prefix assigns the multicast group addresses to the requesting nodes using a manual process. TypicallyTypically, the user or administrator whichthat wants to use a multicast address for a particular application requests an address from the network operator using phone, email, or similar means, and the network operator provides the user with a multicast address. Then the user/administrator of the node or application manually configures the application to use the assigned multicast address. This is a relatively simple process; it has been sufficient for certain applications which require manual configuration in any case, or which cannot or do not want to justify a static IANA assignment. The manual assignment works when the number of participants in a group is small, as each participant has to be manually configured. This is the most commonly used technique when the multicast application does not have a static IANA assignment. 3.4. Static IANA Assignment In contrast to manually configured assignment, as described above, static IANA assignment refers to getting an assignment for the particular application directly from IANA. There are two main forms of IANA assignment: global and scope-relative. Guidelines for IANA are described in [RFC3171][I-D.ietf-mboned-rfc3171bis].[I-D.ietf-mboned-rfc3171bis]. 3.4.1. Global IANA Assignment Globally unique address assignment is seen as lucrative because it's the simplest approach for application developers since they can then hard-code the multicast address. Hard-coding requires no lease of the usable multicast address, and likewise the client applications do not need to perform any kind of service discovery (but depending on hard-coded addresses). However, there is an architectural scaling problem with this approach, as it encourages a "land-grab" of the limited multicast address space. [RFC3138] describes how to handle those GLOP assignments (called "eGLOP") which use the private-use AS number space (220.127.116.11/14). It was envisioned that IANA would delegate the responsibility of these to RIRs, which would assign or allocate addresses as best seemed fit. However, this was never carried out as IANA did not make these allocations to RIRs due to procedural reasons. In summary, there are applications which have obtained a global static IANA assignment and while some of the assignments were really needed, others probably should not have been granted. Conversely, there are some applications that have not obtained a static IANA assignment, yet should have requested an assignment and been granted one.3.4.2. Scope-relative IANA Assignment IANA also assigns numbers as an integer offset from the highest address in each IPv4 administrative scope as described in [RFC2365]. For example, the SLPv2 discovery scope-relative offset is "2", so SLPv2 discovery address within IPv4 Local-Scope (18.104.22.168/16) is "22.214.171.124", within the IPv4 Organization Local-Scope (126.96.36.199/14) it is "188.8.131.52", and so on. Similar scope-relative assignments also exist with IPv6 [RFC2375]. As IPv6 multicast addresses have much more flexible scoping, scope- relative assignments are also applicable to global scopes. The assignment policies are described in [RFC3307]. 3.5. Dynamic Assignments The layer 1 of RFC 2908 [RFC2908] described dynamic assignment from Multicast Address Allocation Servers (MAAS) to applications and nodes, with Multicast Address Dynamic Client Allocation Protocol (MADCAP) [RFC2730] as an example. Since then, there hasother mechanisms have also been a proposal forproposed (e.g., DHCPv6 assignment [I-D.jdurand-assign-addr-ipv6-multicast-dhcpv6].[I-D.jdurand-assign-addr-ipv6-multicast-dhcpv6]) but these have not gained traction. It would be rather straightforward to deploy a dynamic assignment protocol which would lease group addresses based on a multicast prefix to theapplications wishing to use multicast. However, only few have implemented MADCAP, and it hasn't been significantly deployed. So, it is not clear if the lack of deployment is due to a currently missing need. Moreover, it is not clear how widely for example the APIs for communication between the multicast application and the MADCAP client operating at the host have been implemented [RFC2771]. An entirely different approach is Session Announcement Protocol (SAP) [RFC2974]. In addition to advertising global multicast sessions, the protocol also has associated ranges of addresses for both IPv4 and IPv6 which can be used by SAP-aware applications to create new groups and new group addresses. Creating a session (and obtaining an address) is a rather tedious process which is why it isn't done all that often. (NoteIt is also worth noting that the IPv6 SAP address is unroutable in the inter-domain multicast.)multicast. A conclusion about dynamic assignment protocols is that: 1. multicast is not significantly attractive in the first place, 2. most applications have a static IANA assignment and thus require no dynamic or manual assignment, 3. those that cannot be easily satisfied with IANA or manual assignment (i.e., where dynamic assignment would be desirable) are rather marginal, or 4. that there are other gaps why dynamic assignments are not seen as a useful approach (for example, issues related to service discovery/rendezvous). In consequence, more work on rendezvous/service discovery would be needed to make dynamic assignments more useful. 4. Summary and Future Directions This section summarizes the mechanisms and analysis discussed in this memo, and presents some potential future directions. 4.1. Prefix Allocation SummaryA summary of prefix allocation methods for ASM is shown in Figure 1. +-------+--------------------------------+--------+--------+ | Sect. | Prefix allocation method | IPv4 | IPv6 | +-------+--------------------------------+--------+--------+ | 2.1.1 | Derived: GLOP | Yes | NoNeed*| | 2.1.2 | Derived: Unicast-prefix-based | No | Yes | | 2.2 | Administratively scoped | Yes | NoNeed*| | 2.3 | Static IANA allocation | NoYes** | No | | 2.4 | Dynamic allocation protocols | No | No | +-------+--------------------------------+--------+--------+ * = the need satisfied by IPv6 unicast-prefix-based allocation. ** = mainly using the AD-HOC block III (former "eGLOP") Figure 1 o Only ASM is affected by the assignment/allocation issues (however, both ASM and SSM have roughly the same address discovery issues).issues. o With IPv4, GLOP allocations seem toprovide a sufficient IPv4 multicast allocation mechanism for now, but could be extendedthose that have 16-bit AS number. IPv4 unicast-prefix based allocation offers some addresses. IANA is also allocating from the AD-HOC block III (former "eGLOP") with especially 32-bit AS number holders in future.mind. Administratively scoped allocations provide the opportunity for internal IPv4 allocations. o Unicast-prefix-basedWith IPv6, unicast-prefix-based addresses and the derivatives provide a good allocation strategy with IPv6,and this also works for scoped multicast addresses. o Dynamic allocations are atoo complex and unnecessary a mechanism. o Static IANA allocations are generally an architecturally unacceptable approach.4.2. Address Assignment SummaryA summary of address assignment methods is shown in Figure 2. +--------+--------------------------------+----------+----------+ | Sect. | Address assignment method | IPv4 | IPv6 | +--------+--------------------------------+----------+----------+ | 3.1 | Derived: link-scope addresses | No | Yes | | 3.2 | SSM (inside the node) | Yes | Yes | | 3.3 | Manual assignment | Yes | Yes | | 3.4.1 | Global IANA/RIR assignment |LastResort|LastResort| | 3.4.2 | Scope-relative IANA assignment | Yes | Yes | | 3.5 | Dynamic assignment protocols | Yes | Yes | +--------+--------------------------------+----------+----------+ Figure 2 o Manually configured assignment is what's typically donetypical today, and works to a sufficient degree in smaller scale. o Global IANA assignment has been done extensively in the past, but it needs to be tightened down to prevent problems caused by "land- grabbing".past. Scope-relative IANA assignment is acceptable but the size of the pool is not very high. Inter-domain routing of IPv6 IANA-assigned prefixes is likely going to be challenging.challenging and as a result that approach is not very appealing. o Dynamic assignment, e.g., MADCAP has been implemented, but there is no wide deployment. So,Therefore, either there are other gaps in the multicast architecture or there is no sufficient demand for it in the first place when manual and static IANA assignments are available. Assignments using SAP also exist but are not common; global SAP assignment is unfeasible with IPv6. o Derived assignments are only applicable in a fringe case of link- scoped multicast. 4.3. Future Actions o Multicast address discovery/"rendezvous" needs to be analyzed at more length, and an adequate solution provided; the result also needs to be written down to be shown to the IANA static assignment requestors.provided. See [I-D.ietf-mboned-addrdisc-problems] and [I-D.ietf-mboned-session-announcement-req] for more. o IPv6 multicast DAD and/or multicast prefix communication mechanisms should be analyzed (e.g., [I-D.jdurand-ipv6-multicast-ra]): whether there is demand or not, and specify if yes. o The IETFThe IETF should consider whether to specify more ranges of the IPv4 administratively scoped address space for static allocation for applications which should not be routed over the Internet (such as backup software, etc. -- so that these wouldn't need to use global addresses which should never leak in any case). o The IETF should seriouslyconsider its static IANA allocations policy, e.g., "locking it down" to a stricter policy (like "IETF Consensus") and looking at developing the discovery/rendezvous functions, if necessary. 5. Acknowledgements Tutoring a couple of multicast-related papers, the latest by Kaarle Ritvanen [RITVANEN] convinced the author that updated multicast address assignment/allocation documentation is needed. Multicast address allocations/assignments were discussed at the MBONED WG session at IETF59 [MBONED-IETF59]. Dave Thaler, James Lingard, and Beau Williamson provided useful feedback for the preliminary version of this memo. Myung-Ki Shin, Jerome Durand, John Kristoff, Dave Price, andSpencer DawkinsDawkins, and Alfred Hoenes also suggested improvements. 6. IANA Considerations This memo includes no request to IANA, but as the allocation and assignment of multicast addresses are related to IANA functions, it wouldn't hurt if the IANA reviewed this entire memo.IANA. IANA considerations in sections 4.1.1 and 4.1.2 of obsoleted and now Historic [RFC2908] still apply to the administratively scoped prefixes.were never implemented in IANA registry. No update is necessary. (RFC-editor: This section may be interested in reviewing the accuracy ofremoved prior to publication; alternatively, the statement on eGLOP address assignments in Section 3.4.1. (RFC-editor: please remove this section at publication.)second paragraph may be left intact.) 7. Security Considerations This memo only describes different approaches to allocating and assigning multicast addresses, and this has no security considerations; the security analysis of the mentioned protocols is out of scope of this memo. Obviously, especially the dynamic assignment protocols are inherently vulnerable to resource exhaustion attacks, as discussed e.g., in [RFC2730]. 8. References 8.1. Normative References [I-D.ietf-mboned-ipv4-uni-based-mcast] Thaler, D., "Unicast-Prefix-based IPv4 Multicast Addresses", draft-ietf-mboned-ipv4-uni-based-mcast-06 (work in progress), March 2009. [I-D.ietf-mboned-rfc3171bis] Cotton, M., Vegoda, L., and D. Meyer, "IANA Guidelines for IPv4 Multicast Address Assignments", draft-ietf-mboned-rfc3171bis-07 (work in progress), April 2009. [RFC2365] Meyer, D., "Administratively Scoped IP Multicast", BCP 23, RFC 2365, July 1998. [RFC3171] Albanna, Z., Almeroth, K., Meyer, D., and M. Schipper, "IANA Guidelines for IPv4 Multicast Address Assignments", BCP 51, RFC 3171, August 2001.[RFC3180] Meyer, D. and P. Lothberg, "GLOP Addressing in 233/8", BCP 53, RFC 3180, September 2001. [RFC3306] Haberman, B. and D. Thaler, "Unicast-Prefix-based IPv6 Multicast Addresses", RFC 3306, August 2002. [RFC3307] Haberman, B., "Allocation Guidelines for IPv6 Multicast Addresses", RFC 3307, August 2002. [RFC3513] Hinden, R. and S. Deering, "Internet Protocol Version 6 (IPv6) Addressing Architecture", RFC 3513, April 2003.[RFC3956] Savola, P. and B. Haberman, "Embedding the Rendezvous Point (RP) Address in an IPv6 Multicast Address", RFC 3956, November 2004. [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, February 2006. [RFC4489] Park, J-S., Shin, M-K., and H-J. Kim, "A Method for Generating Link-Scoped IPv6 Multicast Addresses", RFC 4489, April 2006. [RFC4607] Holbrook, H. and B. Cain, "Source-Specific Multicast for IP", RFC 4607, August 2006. 8.2. Informative References [I-D.ietf-idr-as4bytes] Vohra, Q. and E. Chen, "BGP Support for Four-octet AS Number Space", draft-ietf-idr-as4bytes-12 (work in progress), November 2005.[I-D.ietf-malloc-aap] Handley, M. and S. Hanna, "Multicast Address Allocation Protocol (AAP)", June 2000. [I-D.ietf-mboned-addrdisc-problems] Savola, P., "Lightweight Multicast Address Discovery Problem Space", draft-ietf-mboned-addrdisc-problems-02 (work in progress), March 2006. [I-D.ietf-mboned-ipv4-uni-based-mcast] Thaler, D., "Unicast-Prefix-based IPv4 Multicast Addresses", draft-ietf-mboned-ipv4-uni-based-mcast-02 (work in progress), October 2004. [I-D.ietf-mboned-rfc3171bis] Albanna, Z., Almeroth, K., Cotton, M.,[I-D.ietf-mboned-session-announcement-req] Asaeda, H. and D. Meyer, "IANA GuidelinesV. Roca, "Requirements for IPv4IP Multicast Address Assignments", draft-ietf-mboned-rfc3171bis-02Session Announcement in the Internet", draft-ietf-mboned-session-announcement-req-01 (work in progress), March 2004.2009. [I-D.jdurand-assign-addr-ipv6-multicast-dhcpv6] Durand, J., "IPv6 multicast address assignment with DHCPv6", draft-jdurand-assign-addr-ipv6-multicast-dhcpv6-01 (work in progress), February 2005. [I-D.jdurand-ipv6-multicast-ra] Durand, J. and P. Savola, "Route Advertisement Option for IPv6 Multicast Prefixes", draft-jdurand-ipv6-multicast-ra-00 (work in progress), February 2005.[MBONED-IETF59] "MBONED WG session at IETF59", <http://www.ietf.org/proceedings/04mar/172.htm>. [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [RFC2375] Hinden, R. and S. Deering, "IPv6 Multicast Address Assignments", RFC 2375, July 1998. [RFC2608] Guttman, E., Perkins, C., Veizades, J., and M. Day, "Service Location Protocol, Version 2", RFC 2608, June 1999.[RFC2730] Hanna, S., Patel, B., and M. Shah, "Multicast Address Dynamic Client Allocation Protocol (MADCAP)", RFC 2730, December 1999. [RFC2771] Finlayson, R., "An Abstract API for Multicast Address Allocation", RFC 2771, February 2000. [RFC2776] Handley, M., Thaler, D., and R. Kermode, "Multicast-Scope Zone Announcement Protocol (MZAP)", RFC 2776, February 2000. [RFC2908] Thaler, D., Handley, M., and D. Estrin, "The Internet Multicast Address Allocation Architecture", RFC 2908, September 2000. [RFC2909] Radoslavov, P., Estrin, D., Govindan, R., Handley, M., Kumar, S., and D. Thaler, "The Multicast Address-Set Claim (MASC) Protocol", RFC 2909, September 2000. [RFC2974] Handley, M., Perkins, C., and E. Whelan, "Session Announcement Protocol", RFC 2974, October 2000. [RFC3138] Meyer, D., "Extended Assignments in 233/8", RFC 3138, June 2001.[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [RFC4893] Vohra, Q. and E. Chen, "BGP Support for Four-octet AS Number Space", RFC 4893, May 2007. [RITVANEN] Ritvanen, K., "Multicast Routing and Addressing", HUT Report, Seminar on Internetworking, May 2004, <http://www.tml.hut.fi/Studies/T-110.551/2004/papers/>. Appendix A. Changes (To be removed prior to publication as an RFC.) A.1. Changes between -05 and -06 o Editorial updates. o Obsolete only RFC2908; the rest only move to Historic. o Category is Informational instead of BCP (in line with the routing architecture. o Move 3171bis and v4-uni-based to Normative references in order to make sure we don't go forward until they're resolved. o Resolve pending issues per IETF75 discussion, in particular major changes to eGLOP and IANA policy discussions. A.2. Changes between -04 and -05 o Editorial updates. These and the following are from Spencer Dawkins. o New text explictlyexplicitly stating that GLOP for v6 is not needed and GLOP for 4byte ASNs isn't (and likely won't be) defined. o Expand reasons for filtering difficulties with global IANA assignments for local apps, and that it would be easier if these were done from the local pool. o Explicitly mention dynamic allocations protocols' lack of benefit and abandonment. A.2.A.3. Changes between -03 and -04 o S/scope-relative/administratively scoped/ and expand Static IANA Assignment section to two subsections; mainly from Dave Price. o Mention the routing challenges of IPv6 IANA assigned prefixes in section 4.2 A.3.A.4. Changes between -02 and -03 o Reword architectural implications of Static IANA and editorial improvements; mainly from John Kristoff. A.4.A.5. Changes between -01 and -02 o Mention the mechanisms which haven't been so succesful:successful: eGLOP and MZAP. o Remove the appendices on multicast address discovery (a separate draft now) and IPv4 unicast-prefix-based multicast addressing. o Add a note on administratively scoped address space and the expansion ambiguity. o Remove the references to draft-ietf-mboned-ipv6-issues-xx.txt o Minor editorial cleanups. Author's Address Pekka Savola CSC - Scientific Computing Ltd. Espoo Finland Email: firstname.lastname@example.org Full Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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