Lightweight 4over6: An Extension to the Dual-Stack Lite Architecture
RFC 7596
Internet Engineering Task Force (IETF) Y. Cui
Request for Comments: 7596 Tsinghua University
Category: Standards Track Q. Sun
ISSN: 2070-1721 China Telecom
M. Boucadair
France Telecom
T. Tsou
Huawei Technologies
Y. Lee
Comcast
I. Farrer
Deutsche Telekom AG
July 2015
Lightweight 4over6: An Extension to the Dual-Stack Lite Architecture
Abstract
Dual-Stack Lite (DS-Lite) (RFC 6333) describes an architecture for
transporting IPv4 packets over an IPv6 network. This document
specifies an extension to DS-Lite called "Lightweight 4over6", which
moves the Network Address and Port Translation (NAPT) function from
the centralized DS-Lite tunnel concentrator to the tunnel client
located in the Customer Premises Equipment (CPE). This removes the
requirement for a Carrier Grade NAT function in the tunnel
concentrator and reduces the amount of centralized state that must be
held to a per-subscriber level. In order to delegate the NAPT
function and make IPv4 address sharing possible, port-restricted IPv4
addresses are allocated to the CPEs.
Status of This Memo
This is an Internet Standards Track document.
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). Further information on
Internet Standards is available in 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/rfc7596.
Cui, et al. Standards Track [Page 1]
RFC 7596 Lightweight 4over6 July 2015
Copyright Notice
Copyright (c) 2015 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
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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.
Table of Contents
1. Introduction ....................................................3
2. Conventions .....................................................4
3. Terminology .....................................................5
4. Lightweight 4over6 Architecture .................................6
5. Lightweight B4 Behavior .........................................7
5.1. Lightweight B4 Provisioning with DHCPv6 ....................7
5.2. Lightweight B4 Data-Plane Behavior ........................10
5.2.1. Fragmentation Behavior .............................11
6. Lightweight AFTR Behavior ......................................12
6.1. Binding Table Maintenance .................................12
6.2. lwAFTR Data-Plane Behavior ................................13
7. Additional IPv4 Address and Port-Set Provisioning Mechanisms ...14
8. ICMP Processing ................................................14
8.1. ICMPv4 Processing by the lwAFTR ...........................15
8.2. ICMPv4 Processing by the lwB4 .............................15
9. Security Considerations ........................................15
10. References ....................................................16
10.1. Normative References .....................................16
10.2. Informative References ...................................17
Acknowledgements ..................................................19
Contributors ......................................................19
Authors' Addresses ................................................21
Cui, et al. Standards Track [Page 2]
RFC 7596 Lightweight 4over6 July 2015
1. Introduction
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