An Anycast Prefix for 6to4 Relay Routers (RFC3068)
Original Publication Date: 2001-Jun-01
Included in the Prior Art Database: 2019-Feb-14
Internet Society Requests For Comment (RFCs)
This memo introduces a "6to4 anycast address" in order to simplify the configuration of 6to4 routers. It also defines how this address will be used by 6to4 relay routers, how the corresponding "6to4 anycast prefix" will be advertised in the IGP and in the EGP. The memo documents the reservation by IANA (Internet Assigned Numbers Authority) of the "6to4 relay anycast prefix." [STANDARDS-TRACK]
Network Working Group C. Huitema Request for Comments: 3068 Microsoft Category: Standards Track June 2001
An Anycast Prefix for 6to4 Relay Routers
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 (C) The Internet Society (2001). All Rights Reserved.
This memo introduces a "6to4 anycast address" in order to simplify the configuration of 6to4 routers. It also defines how this address will be used by 6to4 relay routers, how the corresponding "6to4 anycast prefix" will be advertised in the IGP and in the EGP. The memo documents the reservation by IANA (Internet Assigned Numbers Authority) of the "6to4 relay anycast prefix."
According to [RFC3056], there are two deployment options for a 6to4 routing domain, depending on whether or not the domain is using an IPv6 exterior routing protocol. If a routing protocol is used, then the 6to4 routers acquire routes to all existing IPv6 networks through the combination of EGP and IGP. If no IPv6 exterior routing protocol is used, the 6to4 routers using a given relay router each have a default IPv6 route pointing to the relay router. This second case is typically used by small networks; for these networks, finding and configuring the default route is in practice a significant hurdle. In addition, even when the managers of these networks find an available route, this route often points to a router on the other side of the Internet, leading to very poor performance.
The operation of 6to4 routers requires either that the routers participate in IPv6 inter-domain routing, or that the routers be provisioned with a default route. This memo proposes a standard method to define the default route. It introduces the IANA assigned "6to4 Relay anycast prefix" from which 6to4 packets will be
Huitema Standards Track [Page 1]
RFC 3068 An Anycast Prefix for 6to4 Relay Routers June 2001
automatically routed to the nearest available router. It allows the managers of the 6to4 relay routers to control the sources authorized to use their resource. It makes it easy to set up a large number of 6to4 relay routers, thus enabling scalability.
This memo uses the definitions introduced in [RFC3056], in particular the definition of a 6to4 router and a 6to4 Relay Router. It adds the definition of the 6to4 Relay anycast prefix, 6to4 Relay anycast address, 6to4 IPv6 relay anycast address, and Equivalent IPv4 unicast address.
2.1 6to4 router (or 6to4 border router)
An IPv6 router supporting a 6to4 pseudo-interface. It is normally the border router between an IPv6 site and a wide-area IPv4 network.
2.2 6to4 Relay Router
A 6to4 router configured to support transit routing between...