IPv4-Mapped Address API Considered Harmful

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Last updated 2003-10-23
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The IPv6 Addressing Architecture [Hinden, 1998] defines the 'IPv4-mapped IPv6 address.' This representation is used in the IPv6 basic API [Gilligan, 1999] to denote IPv4 addresses using AF_INET6 sockets. The use of IPv4-mapped addresses on AF_INET6 sockets degrades portability, complicates IPv6 systems, and is likely to create security problems. This document discusses each issue in turn. Finally, it proposes to resolve these problems by recommending deprecation of this mechanism.


Christopher Metz (cmetz@vnet.ibm.com)
Jun-ichiro Itoh (itojun@iijlab.net)

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