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IAB Considerations for UNilateral Self-Address Fixing (UNSAF) Across Network Address Translation

The information below is for an old version of the document that is already published as an RFC.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 3424.
Authors IAB , Leslie Daigle
Last updated 2020-01-21 (Latest revision 2002-07-02)
RFC stream Internet Architecture Board (IAB)
Intended RFC status Informational
Stream IAB state (None)
Consensus boilerplate Unknown
IAB shepherd (None)
A new Request for Comments is now available in online RFC libraries.

        RFC 3424
        Title:      IAB Considerations for UNilateral Self-Address
                    Fixing (UNSAF) Across Network Address Translation
        Author(s):  L. Daigle, Ed., IAB
        Status:     Informational
        Date:       November 2002
        Pages:      9
        Characters: 18165
        Updates/Obsoletes/SeeAlso:   None
        I-D Tag:    draft-iab-unsaf-considerations-02.txt


As a result of the nature of Network Address Translation (NAT)
Middleboxes, communicating endpoints that are separated by one or more
NATs do not know how to refer to themselves using addresses that are
valid in the addressing realms of their (current and future) peers.
Various proposals have been made for "UNilateral Self-Address Fixing
(UNSAF)" processes.  These are processes whereby some originating
endpoint attempts to determine or fix the address (and port) by
which it is known to another endpoint - e.g. to be able to use
address data in the protocol exchange, or to advertise a public
address from which it will receive connections.

This document outlines the reasons for which these proposals can be
considered at best as short term fixes to specific problems and the
specific issues to be carefully evaluated before creating an UNSAF

This document is a product of the Internet Architecture Board.

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