RADIUS Delegated-IPv6-Prefix Attribute
RFC 4818
Network Working Group J. Salowey
Request for Comments: 4818 R. Droms
Category: Standards Track Cisco Systems, Inc.
April 2007
RADIUS Delegated-IPv6-Prefix Attribute
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 IETF Trust (2007).
Abstract
This document defines a RADIUS (Remote Authentication Dial In User
Service) attribute that carries an IPv6 prefix that is to be
delegated to the user. This attribute is usable within either RADIUS
or Diameter.
Salowey & Droms Standards Track [Page 1]
RFC 4818 Delegated-IPv6-Prefix Attribute April 2007
1. Introduction
This document defines the Delegated-IPv6-Prefix attribute as a RADIUS
[1] attribute that carries an IPv6 prefix to be delegated to the
user, for use in the user's network. For example, the prefix in a
Delegated-IPv6-Prefix attribute can be delegated to another node
through DHCP Prefix Delegation [2].
The Delegated-IPv6-Prefix attribute can be used in DHCP Prefix
Delegation between the delegating router and a RADIUS server, as
illustrated in the following message sequence.
Requesting Router Delegating Router RADIUS Server
| | |
|-Solicit------------>| |
| |-Request------------------------>|
| |<--Accept(Delegated-IPv6-Prefix)-|
|<--Advertise(Prefix)-| |
|-Request(Prefix)---->| |
|<--Reply(Prefix)-----| |
| | |
DHCP PD RADIUS
The Framed-IPv6-Prefix attribute [4] is not designed to support
delegation of IPv6 prefixes to be used in the user's network, and
therefore Framed-IPv6-Prefix and Delegated-IPv6-Prefix attributes may
be included in the same RADIUS packet.
2. Terminology
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 RFC 2119 [3].
Salowey & Droms Standards Track [Page 2]
RFC 4818 Delegated-IPv6-Prefix Attribute April 2007
3. Attribute Format
The format of the Delegated-IPv6-Prefix is:
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Reserved | Prefix-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Prefix
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Prefix
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Prefix
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Prefix |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
123 for Delegated-IPv6-Prefix
Length
The length of the entire attribute, in bytes. At least 4 (to
hold Type/Length/Reserved/Prefix-Length for a 0-bit prefix),
and no larger than 20 (to hold Type/Length/ Reserved/Prefix-
Length for a 128-bit prefix)
Reserved
Always set to zero by sender; ignored by receiver
Prefix-Length
The length of the prefix being delegated, in bits. At least
0 and no larger than 128 bits (identifying a single IPv6
address)
Note that the prefix field is only required to be long enough to hold
the prefix bits and can be shorter than 16 bytes. Any bits in the
Show full document text