Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)
ISATAP is the Intra-Site Automatic Tunnel Addressing Protocol; it is used for automatic deployment of IPv6 in IPv4 sites. ISATAP specifies an IPv6-IPv4 compatibility address format as well as a means for site border router discovery. ISATAP also specifies the operation of IPv6 over a specific link layer - that being IPv4 used as a link layer for IPv6.

As of March 2008, ISATAP has been re-published as an informational-category RFC [RFC5214] which obsoletes the previous experimental-category version [RFC4214]. A development history of RFC4214 is on the ISATAP Issue Tracker Page

As of April 2008, ISATAP is implemented in the publicly available Linux operating system kernel, beginning with linux-2.6.25. ISATAP is also implemented in other widely-deployed systems including Microsoft Windows XP, Microsoft Windows Vista, cisco IOS, 6WIND 6WINDGate, and FreeBSD/KAME.

A new architecture called Routing and Addressing in Next-Generation EnteRprises (RANGER) is now available. RANGER is an architectural framework that builds on ISATAP principles to also include IPv6 autoconfiguration, IPv6 prefix delegation, router-to-router tunneling, adaptation to diverse tunnel MTUs and IPv6 multicast. RANGER combines the functional elements specified in Virtual Enterprise Traversal (VET) and the Subnetwork Adaptation and Encapsulation Layer (SEAL).

The Internet Routing Overlay Network (IRON) reaches far beyond the basic features offered in other IPv6-in-IPv4 tunneling mechanisms with a guiding principle of supporting scalable Provider Independent (PI) addressing for end user networks. IRON also incorporates network mobility management, multihoming, multiple interfaces, traffic engineering and other important concepts such as any-within-any encapsulation and robust path MTU discovery. IRON is progressing as an RFC publication of the IRTF Routing Research Group, and is intended as a long-term solution rather than a transition mechanism. A presentation slide set is found here.


 Other I SATAP-related links:
Towards the full Deployment of IPv6 - the Experience at Swisscom Innovations
 Ericsson Roams on IPv6
 Linux ISATAP Setup
 ISATAP automatic configuration with DHCP4
 JOIN Homepage - Howto install and configure ISATAP?
 isatap.kddilabs.jp Page (in Japanese)
 Internet Protocol Version 6 (Microsoft)
Cisco IOS Software Release 12.3T New Features and Platforms
 Implementing Tunneling for IPv6 (cisco)
 Federal Agencies and the Transition to IPv6
 How to use ISATAP on KAME
 The Implementation of ISATAP Router (on Linux)
 Miredo project unleashes ISATAP server
 ISATAP - Wikipedia, the free encyclopedia


NEW: A feature-wise comparison of several popular tunneling mechanisms is here.