NAT Port Mapping Protocol (NAT-PMP)
RFC 6886
| Document | Type |
RFC - Informational
(April 2013; Errata)
Was draft-cheshire-nat-pmp (individual)
|
|
|---|---|---|---|
| Last updated | 2020-01-21 | ||
| Stream | ISE | ||
| Formats | plain text html pdf htmlized with errata bibtex | ||
| IETF conflict review | conflict-review-cheshire-nat-pmp | ||
| Stream | ISE state | Published RFC | |
| Consensus Boilerplate | Unknown | ||
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 6886 (Informational) | |
| Telechat date | |||
| Responsible AD | (None) | ||
| Send notices to | (None) | ||
Independent Submission S. Cheshire
Request for Comments: 6886 M. Krochmal
Category: Informational Apple Inc.
ISSN: 2070-1721 April 2013
NAT Port Mapping Protocol (NAT-PMP)
Abstract
This document describes a protocol for automating the process of
creating Network Address Translation (NAT) port mappings. Included
in the protocol is a method for retrieving the external IPv4 address
of a NAT gateway, thus allowing a client to make its external IPv4
address and port known to peers that may wish to communicate with it.
From 2005 onwards, this protocol was implemented in Apple products
including Mac OS X, Bonjour for Windows, and AirPort wireless base
stations. In 2013, NAT Port Mapping Protocol (NAT-PMP) was
superseded by the IETF Standards Track RFC "Port Control Protocol
(PCP)", which builds on NAT-PMP and uses a compatible packet format,
but adds a number of significant enhancements.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This is a contribution to the RFC Series, independently of any other
RFC stream. The RFC Editor has chosen to publish this document at
its discretion and makes no statement about its value for
implementation or deployment. Documents approved for publication by
the RFC Editor are not a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6886.
Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document.
Cheshire & Krochmal Informational [Page 1]
RFC 6886 NAT-PMP April 2013
Table of Contents
1. Introduction ....................................................3
1.1. Transition to Port Control Protocol ........................4
2. Conventions and Terminology Used in This Document ...............5
3. Protocol and Packet Format ......................................5
3.1. Requests and Responses .....................................6
3.2. Determining the External Address ...........................7
3.3. Requesting a Mapping ......................................10
3.4. Destroying a Mapping ......................................13
3.5. Result Codes ..............................................14
3.6. Seconds Since Start of Epoch ..............................16
3.7. Recreating Mappings on NAT Gateway Reboot .................16
3.8. NAT Gateways with NAT Function Disabled ...................18
3.9. All Mappings Are Bidirectional ............................19
4. UNSAF Considerations ...........................................20
4.1. Scope .....................................................20
4.2. Transition Plan ...........................................20
4.3. Failure Cases .............................................21
4.4. Long-Term Solution ........................................23
4.5. Existing Deployed NATs ....................................23
5. Security Considerations ........................................23
6. IANA Considerations ............................................24
7. Acknowledgments ................................................24
8. Deployment History .............................................25
9. Noteworthy Features of NAT Port Mapping Protocol and PCP .......26
9.1. Simplicity ................................................27
9.2. Focused Scope .............................................27
9.3. Efficiency ................................................27
9.4. Atomic Allocation Operations ..............................29
9.5. Garbage Collection ........................................29
9.6. State Change Announcements ................................30
9.7. Soft State Recovery .......................................31
9.8. On-Path NAT Discovery .....................................31
10. References ....................................................32
10.1. Normative References .....................................32
10.2. Informative References ...................................32
Cheshire & Krochmal Informational [Page 2]
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