Renumbering Requirements for Stateless Dynamic Host Configuration Protocol for IPv6 (DHCPv6)
RFC 4076
Network Working Group T. Chown
Request for Comments: 4076 University of Southampton
Category: Informational S. Venaas
UNINETT
A. Vijayabhaskar
Cisco Systems (India) Private Limited
May 2005
Renumbering Requirements for Stateless
Dynamic Host Configuration Protocol for IPv6 (DHCPv6)
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
IPv6 hosts using Stateless Address Autoconfiguration are able to
configure their IPv6 address and default router settings
automatically. However, further settings are not available. If
these hosts wish to configure their DNS, NTP, or other specific
settings automatically, the stateless variant of the Dynamic Host
Configuration Protocol for IPv6 (DHCPv6) could be used. This
combination of Stateless Address Autoconfiguration and stateless
DHCPv6 could be used quite commonly in IPv6 networks. However, hosts
using this combination currently have no means by which to be
informed of changes in stateless DHCPv6 option settings; e.g., the
addition of a new NTP server address, a change in DNS search paths,
or full site renumbering. This document is presented as a problem
statement from which a solution should be proposed in a subsequent
document.
Chown, et al. Informational [Page 1]
RFC 4076 Renumbering for Stateless DHCPv6 May 2005
Table of Contents
1. Introduction ...................................................2
2. Problem Statement ..............................................3
3. Renumbering Scenarios ..........................................3
3.1. Site Renumbering .........................................4
3.2. Changes to a DHCPv6-assigned Setting .....................4
4. Renumbering Requirements .......................................4
5. Considerations in Choosing a Solution ..........................4
6. Solution Space .................................................5
7. Summary ........................................................5
8. Security Considerations ........................................6
9. Acknowledgements ...............................................6
10. References .....................................................6
10.1. Normative References .....................................6
10.2. Informative References ...................................6
1. Introduction
IPv6 hosts using Stateless Address Autoconfiguration [2] are able to
configure their IPv6 address and default router settings
automatically. Although Stateless Address Autoconfiguration for IPv6
allows automatic configuration of these settings, it does not provide
a mechanism for additional non IP-address settings to be configured
automatically.
The full version of the Dynamic Host Configuration Protocol for IPv6
(DHCPv6) [3] is designed to provide both stateful address assignment
to IPv6 hosts, as well as additional (non IP-address) configuration
including DNS, NTP, and other specific settings. A full stateful
DHCPv6 server allocates the addresses and maintains the clients'
bindings to keep track of client leases.
If hosts using Stateless Address Autoconfiguration for IPv6 wish to
configure their DNS, NTP, or other specific settings automatically,
the stateless variant [4] of DHCPv6 could be used. This variant is
more lightweight. It does not do address assignment; instead, it
only provides additional configuration parameters, such as DNS
resolver addresses. It does not maintain dynamic state about the
information assigned to clients, and therefore there is no need to
maintain dynamic per-client state on the server.
This combination of Stateless Address Autoconfiguration and stateless
DHCPv6 could be used quite commonly in IPv6 networks.
Chown, et al. Informational [Page 2]
RFC 4076 Renumbering for Stateless DHCPv6 May 2005
2. Problem Statement
A problem, however, lies in the ability, or lack of ability, of
clients using this combination to be informed of (or to deduce)
changes in DHCPv6-assigned settings.
While a DHCPv6 server unicasts Reconfigure messages to individual
clients to trigger them to initiate Information-request/reply
configuration exchanges to update their configuration settings, the
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