Building IPv6 Applications which Access IPv4 Servers

Document Type Expired Internet-Draft (individual)
Last updated 2009-10-26
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


When an application runs on a host or network that only supports IPv6 ("IPv6-only"), it is sometimes necessary that the application communicate with IPv4 peers. When that communication involves DNS, DNS64 and a 6/4 translator works well without any changes to most applications. However, when that communication does not involve DNS, it can require additional features be configured on or programmed into the IPv6 application. This document explains why this functionality is important and describes mechanisms for applications to provide such functionality.


Dan Wing (

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