RFC 3041 (rfc3041) - Page 2 of 17
Privacy Extensions for Stateless Address Autoconfiguration in IPv6
Alternative Format: Original Text Document
RFC 3041 Extensions to IPv6 Address Autoconfiguration January 2001
Table of Contents
1. Introduction............................................. 2
2. Background............................................... 3
2.1. Extended Use of the Same Identifier................. 3
2.2. Address Usage in IPv4 Today......................... 4
2.3. The Concern With IPv6 Addresses..................... 5
2.4. Possible Approaches................................. 6
3. Protocol Description..................................... 7
3.1. Assumptions......................................... 8
3.2. Generation Of Randomized Interface Identifiers...... 9
3.3. Generating Temporary Addresses...................... 10
3.4. Expiration of Temporary Addresses................... 11
3.5. Regeneration of Randomized Interface Identifiers.... 12
4. Implications of Changing Interface Identifiers........... 13
5. Defined Constants........................................ 14
6. Future Work.............................................. 14
7. Security Considerations.................................. 15
8. Acknowledgments.......................................... 15
9. References............................................... 15
10. Authors' Addresses....................................... 16
11. Full Copyright Statement................................. 17
1. Introduction
Stateless address autoconfiguration [ADDRCONF] defines how an IPv6
node generates addresses without the need for a DHCP server. Some
types of network interfaces come with an embedded IEEE Identifier
(i.e., a link-layer MAC address), and in those cases stateless
address autoconfiguration uses the IEEE identifier to generate a 64-
bit interface identifier [ADDRARCH]. By design, the interface
identifier is likely to be globally unique when generated in this
fashion. The interface identifier is in turn appended to a prefix to
form a 128-bit IPv6 address.
All nodes combine interface identifiers (whether derived from an IEEE
identifier or generated through some other technique) with the
reserved link-local prefix to generate link-local addresses for their
attached interfaces. Additional addresses, including site-local and
global-scope addresses, are then created by combining prefixes
advertised in Router Advertisements via Neighbor Discovery
[DISCOVERY] with the interface identifier.
Not all nodes and interfaces contain IEEE identifiers. In such
cases, an interface identifier is generated through some other means
(e.g., at random), and the resultant interface identifier is not
globally unique and may also change over time. The focus of this
document is on addresses derived from IEEE identifiers, as the
Narten & Draves Standards Track