Native IPv6 behind IPv4-to-IPv4 NAT Customer Premises Equipment (6a44)
RFC 6751
| Document | Type |
RFC - Experimental
(October 2012; Errata)
Was draft-despres-6a44 (individual)
|
|
|---|---|---|---|
| Last updated | 2020-01-21 | ||
| Replaces | draft-despres-softwire-6a44, draft-despres-intarea-6a44 | ||
| Stream | ISE | ||
| Formats | plain text html pdf htmlized with errata bibtex | ||
| Stream | ISE state | (None) | |
| Consensus Boilerplate | Unknown | ||
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 6751 (Experimental) | |
| Telechat date | |||
| Responsible AD | Ralph Droms | ||
| IESG note | ISE Submission | ||
| Send notices to | rfc-ise@rfc-editor.org | ||
Independent Submission R. Despres, Ed.
Request for Comments: 6751 RD-IPtech
Category: Experimental B. Carpenter
ISSN: 2070-1721 Univ. of Auckland
D. Wing
Cisco
S. Jiang
Huawei Technologies Co., Ltd.
October 2012
Native IPv6 behind IPv4-to-IPv4 NAT Customer Premises Equipment (6a44)
Abstract
In customer sites having IPv4-only Customer Premises Equipment (CPE),
Teredo (RFC 4380, RFC 5991, RFC 6081) provides last-resort IPv6
connectivity. However, because it is designed to work without the
involvement of Internet Service Providers, it has significant
limitations (connectivity between IPv6 native addresses and Teredo
addresses is uncertain; connectivity between Teredo addresses fails
for some combinations of NAT types). 6a44 is a complementary
solution that, being based on ISP cooperation, avoids these
limitations. At the beginning of 6a44 IPv6 addresses, it replaces
the Teredo well-known prefix, present at the beginning of Teredo IPv6
addresses, with network-specific /48 prefixes assigned by local ISPs
(an evolution similar to that from 6to4 to 6rd (IPv6 Rapid Deployment
on IPv4 Infrastructures)). The specification is expected to be
complete enough for running code to be independently written and the
solution to be incrementally deployed and used.
Despres, et al. Experimental [Page 1]
RFC 6751 Native IPv6 behind NAT44 CPEs (6a44) October 2012
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 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/rfc6751.
Copyright Notice
Copyright (c) 2012 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.
Despres, et al. Experimental [Page 2]
RFC 6751 Native IPv6 behind NAT44 CPEs (6a44) October 2012
Table of Contents
1. Introduction ....................................................3
2. Requirements Language ...........................................5
3. Definitions .....................................................5
4. Design Goals, Requirements, and Model of Operation ..............7
4.1. Hypotheses about NAT Behavior ..............................7
4.2. Native IPv6 Connectivity for Unmanaged Hosts behind
NAT44s .....................................................7
4.3. Operational Requirements ...................................8
4.4. Model of Operation .........................................9
5. 6a44 Addresses .................................................12
6. Specification of Clients and Relays ............................14
6.1. Packet Formats ............................................14
6.2. IPv6 Packet Encapsulations ................................14
6.3. 6a44 Bubbles ..............................................14
6.4. MTU Considerations ........................................16
6.5. 6a44 Client Specification .................................16
6.5.1. Tunnel Maintenance .................................16
6.5.2. Client Transmission ................................19
6.5.3. Client Reception ...................................20
6.6. 6a44 Relay Specification ..................................23
6.6.1. Relay Reception in IPv6 ............................23
6.6.2. Relay Reception in IPv4 ............................24
6.7. Implementation of Automatic Sunset ........................26
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