IPv4 Residual Deployment across IPv6-Service networks (4rd) ISP-NAT's made optional

Document Type Expired Internet-Draft (individual)
Last updated 2011-03-14
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document specifies an automatic tunneling mechanism for providing IPv4 connectivity service to end users over a service provider's IPv6 network. During the long transition period from IPv4 to IPv6-only, a service provider's network will have to support IPv6, but will also have to maintain some IPv4 connectivity for a number of customers, for both outgoing and incoming connections, and for both exclusive and shared IPv4 addresses. The 4rd solution (IPv4 Residual Deployment) is designed as a lightweight solution for this. In some scenarios, 4rd can dispense ISPs from supporting any NAT in their networks. In some others it can be used in parallel with NAT- based solutions such as DS-lite and/or NAT64/DNS4.


Remi Despres (remi.despres@free.fr)
Satoru Matsushima (satoru.matsushima@tm.softbank.co.jp)
Tetsuya Murakami (tetsuya@ipinfusion.com)
Ole Trøan (ot@cisco.com)

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)