Default Address Selection for Internet Protocol Version 6 (IPv6) (RFC6724)
Original Publication Date: 2012-Sep-01
Included in the Prior Art Database: 2012-Sep-11
Internet Society Requests For Comment (RFCs)
D. Thaler: AUTHOR [+5]
The IPv6 addressing architecture [RFC4291] allows multiple unicast addresses to be assigned to interfaces. These addresses might have different reachability scopes (link-local, site-local, or global). These addresses might also be "preferred" or "deprecated" [RFC4862]. Privacy considerations have introduced the concepts of "public addresses" and "temporary addresses" [RFC4941]. The mobility architecture introduces "home addresses" and "care-of addresses" [RFC6275]. In addition, multi-homing situations will result in more addresses per node. For example, a node might have multiple interfaces, some of them tunnels or virtual interfaces, or a site might have multiple ISP attachments with a global prefix per ISP.
Internet Engineering Task Force (IETF) D. Thaler, Ed. Request for Comments: 6724 Microsoft Obsoletes: 3484 R. Draves Category: Standards Track Microsoft Research ISSN: 2070-1721 A. Matsumoto NTT T. Chown University of Southampton September 2012
Default Address Selection for Internet Protocol Version 6 (IPv6)
This document describes two algorithms, one for source address selection and one for destination address selection. The algorithms specify default behavior for all Internet Protocol version 6 (IPv6) implementations. They do not override choices made by applications or upper-layer protocols, nor do they preclude the development of more advanced mechanisms for address selection. The two algorithms share a common context, including an optional mechanism for allowing administrators to provide policy that can override the default behavior. In dual-stack implementations, the destination address selection algorithm can consider both IPv4 and IPv6 addresses -- depending on the available source addresses, the algorithm might prefer IPv6 addresses over IPv4 addresses, or vice versa.
Default address selection as defined in this specification applies to all IPv6 nodes, including both hosts and routers. This document obsoletes RFC 3484.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc6724.
Thaler, et al. Standards Track [Page 1]
RFC 6724 Default Address Selection for IPv6 September 2012