The Address plus Port (A+P) Approach to the IPv4 Address Shortage
RFC 6346
Document | Type |
RFC - Experimental
(August 2011; No errata)
Was draft-ymbk-aplusp (individual in ops area)
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Author | Randy Bush | ||
Last updated | 2018-12-20 | ||
Replaces | draft-boucadair-behave-ipv6-portrange | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 6346 (Experimental) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Ron Bonica | ||
Send notices to | (None) |
Internet Engineering Task Force (IETF) R. Bush, Ed. Request for Comments: 6346 Internet Initiative Japan Category: Experimental August 2011 ISSN: 2070-1721 The Address plus Port (A+P) Approach to the IPv4 Address Shortage Abstract We are facing the exhaustion of the IANA IPv4 free IP address pool. Unfortunately, IPv6 is not yet deployed widely enough to fully replace IPv4, and it is unrealistic to expect that this is going to change before the depletion of IPv4 addresses. Letting hosts seamlessly communicate in an IPv4 world without assigning a unique globally routable IPv4 address to each of them is a challenging problem. This document proposes an IPv4 address sharing scheme, treating some of the port number bits as part of an extended IPv4 address (Address plus Port, or A+P). Instead of assigning a single IPv4 address to a single customer device, we propose to extend the address field by using bits from the port number range in the TCP/UDP header as additional endpoint identifiers, thus leaving a reduced range of ports available to applications. This means assigning the same IPv4 address to multiple clients (e.g., Customer Premises Equipment (CPE), mobile phones), each with its assigned port range. In the face of IPv4 address exhaustion, the need for addresses is stronger than the need to be able to address thousands of applications on a single host. If address translation is needed, the end-user should be in control of the translation process -- not some smart boxes in the core. Bush Experimental [Page 1] RFC 6346 A+P Addressing Extension August 2011 Status of This Memo This document is not an Internet Standards Track specification; it is published for examination, experimental implementation, and evaluation. This document defines an Experimental Protocol for the Internet community. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are 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/rfc6346. Copyright Notice Copyright (c) 2011 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. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Bush Experimental [Page 2] RFC 6346 A+P Addressing Extension August 2011 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Problems with Carrier Grade NATs . . . . . . . . . . . . . 4 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Design Constraints and Functions . . . . . . . . . . . . . . . 6 3.1. Design Constraints . . . . . . . . . . . . . . . . . . . . 6 3.2. A+P Functions . . . . . . . . . . . . . . . . . . . . . . 7 3.3. Overview of the A+P Solution . . . . . . . . . . . . . . . 8 3.3.1. Signaling . . . . . . . . . . . . . . . . . . . . . . 9 3.3.2. Address Realm . . . . . . . . . . . . . . . . . . . . 11 3.3.3. Reasons for Allowing Multiple A+P Gateways . . . . . . 15 3.3.4. Overall A+P Architecture . . . . . . . . . . . . . . . 16 3.4. A+P Experiments . . . . . . . . . . . . . . . . . . . . . 17 4. Stateless A+P Mapping Function . . . . . . . . . . . . . . . . 18 4.1. Stateless A+P Mapping (SMAP) Gateway Function Description . . . . . . . . . . . . . . . . . . . . . . . 18 4.2. Implementation Mode . . . . . . . . . . . . . . . . . . . 20 4.3. Towards IPv6-Only Networks . . . . . . . . . . . . . . . . 22 4.4. PRR: On Stateless and Binding Table Modes . . . . . . . . 22 4.5. General Recommendations on SMAP . . . . . . . . . . . . . 23 5. Deployment Scenarios . . . . . . . . . . . . . . . . . . . . . 24Show full document text