A Method for Generating Link-Scoped IPv6 Multicast Addresses
RFC 4489
| Document | Type |
RFC - Proposed Standard
(April 2006; No errata)
Updates RFC 3306
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 4489 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Margaret Cullen | ||
| Send notices to | (None) | ||
Network Working Group J-S. Park
Request for Comments: 4489 M-K. Shin
Updates: 3306 H-J. Kim
Category: Standards Track ETRI
April 2006
A Method for Generating Link-Scoped IPv6 Multicast Addresses
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
This document specifies an extension to the multicast addressing
architecture of the IPv6 protocol. The extension allows the use of
Interface Identifiers (IIDs) to allocate multicast addresses. When a
link-local unicast address is configured at each interface of a node,
an IID is uniquely determined. After that, each node can generate
its unique multicast addresses automatically without conflicts. The
alternative method for creating link-local multicast addresses
proposed in this document is better than known methods like unicast-
prefix-based IPv6 multicast addresses. This memo updates RFC 3306.
Table of Contents:
1. Introduction ....................................................2
2. Applicability ...................................................2
3. Link-Scoped Multicast Address Format ............................3
4. Example .........................................................3
5. Consideration of Lifetime .......................................4
6. Security Considerations .........................................4
7. Acknowledgements ................................................4
8. References ......................................................5
Park, et al. Standards Track [Page 1]
RFC 4489 Link-Scoped IPv6 Multicast April 2006
1. Introduction
This document defines an extension to the multicast portion of the
IPv6 addressing architecture [RFC4291]. The current architecture
does not contain any built-in support for dynamic address allocation.
The extension allows for use of IIDs to allocate multicast addresses.
When a link-local unicast address is configured at each interface of
a node, an IID is uniquely determined. After that, each node can
generate its unique multicast addresses automatically without
conflicts. That is, these addresses could safely be configured at
any time after Duplicate Address Detection (DAD) has completed.
This method for the link-local scope is preferred over unicast-
prefix-based IPv6 multicast addresses [RFC3306], since by delegating
multicast addresses using the IID, each node can generate its
multicast addresses automatically without allocation servers. This
method works better than the unicast-prefix-based method with
applications in serverless environments such as ad-hoc and network
mobility. This document restricts the usage of defined fields such
as the scop, plen, and network prefix fields of [RFC3306].
Therefore, this document specifies encoded information for link-local
scope in multicast addresses.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. Applicability
The allocation technique in this document is designed to be used in
any environment in which link-local scope IPv6 multicast addresses
are assigned or selected. This method goes especially well with
nodes supplying multicast services in a zeroconf/serverless
environment. For example, multicast addresses less than or equal to
link-local scope are themselves generated by nodes supplying
multicast services without conflicts. Also, hosts that are supplied
multicast services from multicast servers then make multicast
addresses of multicast servers using ND (address resolution) and
well-known group IDs [RFC2461].
Consequently, this technique MUST only be used for link scoped
multicast addresses. If you want to use multicast addresses greater
than link-local scope, you need to use other methods as described in
[RFC3306].
Park, et al. Standards Track [Page 2]
RFC 4489 Link-Scoped IPv6 Multicast April 2006
3. Link-Scoped Multicast Address Format
This document specifies a new format that incorporates IID in the
link-local scope multicast addresses.
Figure 1 illustrates the new format for link-scoped multicast
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