draft-ietf-v6ops-464xlat-10.txt   rfc6877.txt 
Internet Engineering Task Force M. Mawatari Internet Engineering Task Force (IETF) M. Mawatari
Internet-Draft Japan Internet Exchange Co.,Ltd. Request for Comments: 6877 Japan Internet Exchange
Intended status: Informational M. Kawashima Category: Informational M. Kawashima
Expires: August 27, 2013 NEC AccessTechnica, Ltd. ISSN: 2070-1721 NEC AccessTechnica, Ltd.
C. Byrne C. Byrne
T-Mobile USA T-Mobile USA
February 23, 2013 April 2013
464XLAT: Combination of Stateful and Stateless Translation 464XLAT: Combination of Stateful and Stateless Translation
draft-ietf-v6ops-464xlat-10
Abstract Abstract
This document describes an architecture (464XLAT) for providing This document describes an architecture (464XLAT) for providing
limited IPv4 connectivity across an IPv6-only network by combining limited IPv4 connectivity across an IPv6-only network by combining
existing and well-known stateful protocol translation RFC 6146 in the existing and well-known stateful protocol translation (as described
core and stateless protocol translation RFC 6145 at the edge. 464XLAT in RFC 6146) in the core and stateless protocol translation (as
is a simple and scalable technique to quickly deploy limited IPv4 described in RFC 6145) at the edge. 464XLAT is a simple and scalable
access service to IPv6-only edge networks without encapsulation. technique to quickly deploy limited IPv4 access service to IPv6-only
edge networks without encapsulation.
Status of this Memo
This Internet-Draft is submitted in full conformance with the Status of This Memo
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering This document is not an Internet Standards Track specification; it is
Task Force (IETF). Note that other groups may also distribute published for informational purposes.
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." 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.
This Internet-Draft will expire on August 27, 2013. 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/rfc6877.
Copyright Notice Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 26 skipping to change at page 2, line 37
4.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 5 4.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 5
5. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 6 5. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Wireline Network Applicability . . . . . . . . . . . . . . 6 5.1. Wireline Network Applicability . . . . . . . . . . . . . . 6
5.2. Wireless 3GPP Network Applicability . . . . . . . . . . . 7 5.2. Wireless 3GPP Network Applicability . . . . . . . . . . . 7
6. Implementation Considerations . . . . . . . . . . . . . . . . 7 6. Implementation Considerations . . . . . . . . . . . . . . . . 7
6.1. IPv6 Address Format . . . . . . . . . . . . . . . . . . . 7 6.1. IPv6 Address Format . . . . . . . . . . . . . . . . . . . 7
6.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 7 6.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 7
6.3. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 9 6.3. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 9
6.4. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 9 6.4. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 9
6.5. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 9 6.5. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 9
6.6. CLAT to CLAT communications . . . . . . . . . . . . . . . 9 6.6. CLAT-to-CLAT Communications . . . . . . . . . . . . . . . 10
7. Deployment Considerations . . . . . . . . . . . . . . . . . . 10 7. Deployment Considerations . . . . . . . . . . . . . . . . . . 10
7.1. Traffic Engineering . . . . . . . . . . . . . . . . . . . 10 7.1. Traffic Engineering . . . . . . . . . . . . . . . . . . . 10
7.2. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 10 7.2. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 10
8. Security Considerations . . . . . . . . . . . . . . . . . . . 11 8. Security Considerations . . . . . . . . . . . . . . . . . . . 11
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 10.1. Normative References . . . . . . . . . . . . . . . . . . . 11
11.1. Normative References . . . . . . . . . . . . . . . . . . . 11 10.2. Informative References . . . . . . . . . . . . . . . . . . 12
11.2. Informative References . . . . . . . . . . . . . . . . . . 12
Appendix A. Examples of IPv4/IPv6 Address Translation . . . . . . 13 Appendix A. Examples of IPv4/IPv6 Address Translation . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
With the exhaustion of the unallocated IPv4 address pools, it will be With the exhaustion of the unallocated IPv4 address pools, it will be
difficult for many networks to assign IPv4 addresses to end users. difficult for many networks to assign IPv4 addresses to end users.
This document describes an IPv4 over IPv6 solution as one of the This document describes an IPv4-over-IPv6 solution as one of the
techniques for IPv4 service extension and encouragement of IPv6 techniques for IPv4 service extension and encouragement of IPv6
deployment. 464XLAT is not a one-for-one replacement of full IPv4 deployment. 464XLAT is not a one-for-one replacement of full IPv4
functionality. The 464XLAT architecture only supports IPv4 in the functionality. The 464XLAT architecture only supports IPv4 in the
client server model, where the server has a global IPv4 address. client-server model, where the server has a global IPv4 address.
This means it is not fit for IPv4 peer-to-peer communication or This means it is not fit for IPv4 peer-to-peer communication or
inbound IPv4 connections. 464XLAT builds on IPv6 transport and inbound IPv4 connections. 464XLAT builds on IPv6 transport and
includes full any-to-any IPv6 communication. includes full any-to-any IPv6 communication.
The 464XLAT architecture described in this document uses IPv4/IPv6 The 464XLAT architecture described in this document uses IPv4/IPv6
translation standardized in [RFC6145] and [RFC6146]. It does not translation standardized in [RFC6145] and [RFC6146]. It does not
require DNS64 [RFC6147] since an IPv4 host may simply send IPv4 require DNS64 [RFC6147] since an IPv4 host may simply send IPv4
packets, including packets to an IPv4 DNS server, which will be packets, including packets to an IPv4 DNS server, that will be
translated on the customer side translator (CLAT) to IPv6 and back to translated to IPv6 on the customer-side translator (CLAT) and back to
IPv4 on the provider side translator (PLAT). 464XLAT networks may use IPv4 on the provider-side translator (PLAT). 464XLAT networks may
DNS64 [RFC6147] to enable single stateful translation [RFC6146] use DNS64 [RFC6147] to enable single stateful translation [RFC6146]
instead of 464XLAT double translation where possible. The 464XLAT instead of 464XLAT double translation where possible. The 464XLAT
architecture encourages the IPv6 transition by making IPv4 services architecture encourages the IPv6 transition by making IPv4 services
reachable across IPv6-only networks and providing IPv6 and IPv4 reachable across IPv6-only networks and providing IPv6 and IPv4
connectivity to single-stack IPv4 or IPv6 servers and peers. connectivity to single-stack IPv4 or IPv6 servers and peers.
2. Terminology 2. Terminology
PLAT: PLAT is Provider side translator(XLAT) that complies with PLAT: PLAT is provider-side translator (XLAT) that complies with
[RFC6146]. It translates N:1 global IPv6 addresses to global [RFC6146]. It translates N:1 global IPv6 addresses to global
IPv4 addresses, and vice versa. IPv4 addresses, and vice versa.
CLAT: CLAT is Customer side translator(XLAT) that complies with CLAT: CLAT is customer-side translator (XLAT) that complies with
[RFC6145]. It algorithmically translates 1:1 private IPv4 [RFC6145]. It algorithmically translates 1:1 private IPv4
addresses to global IPv6 addresses, and vice versa. The CLAT addresses to global IPv6 addresses, and vice versa. The CLAT
function is applicable to a router or an end-node such as a function is applicable to a router or an end-node such as a
mobile phone. The CLAT should perform IP routing and mobile phone. The CLAT should perform IP routing and
forwarding to facilitate packets forwarding through the forwarding to facilitate packets forwarding through the
stateless translation even if it is an end-node. The CLAT as stateless translation even if it is an end-node. The CLAT as
a common home router or wireless Third Generation Partnership a common home router or wireless Third Generation Partnership
Project (3GPP) router is expected to perform gateway Project (3GPP) router is expected to perform gateway
functions such as DHCP server and DNS proxy for local functions such as being a DHCP server and DNS proxy for local
clients. The CLAT uses different IPv6 prefixes for CLAT-side clients. The CLAT uses different IPv6 prefixes for CLAT-side
and PLAT-side IPv4 addresses and therefore does not comply and PLAT-side IPv4 addresses and therefore does not comply
with the sentence "Both IPv4-translatable IPv6 addresses and with the sentence "Both IPv4-translatable IPv6 addresses and
IPv4-converted IPv6 addresses should use the same prefix." in IPv4-converted IPv6 addresses SHOULD use the same prefix." in
Section 3.3 of [RFC6052]. The CLAT does not facilitate Section 3.3 of [RFC6052]. The CLAT does not facilitate
communications between a local IPv4-only node and an IPv6- communications between a local IPv4-only node and an IPv6-
only node on the Internet. only node on the Internet.
3. Motivation and Uniqueness of 464XLAT 3. Motivation and Uniqueness of 464XLAT
1. Minimal IPv4 resource requirements, maximum IPv4 efficiency The list below describes the motivation for 464XLAT and its unique
through statistical multiplexing. characteristics.
2. No new protocols required, quick deployment. o 464XLAT has minimal IPv4 resource requirements and maximum IPv4
efficiency through statistical multiplexing.
3. IPv6-only networks are simpler and therefore less expensive to o No new protocols are required; there is quick deployment.
operate than dual-stack networks.
4. Consistent native IP based monitoring, traffic engineering, and o IPv6-only networks are simpler and therefore less expensive to
capacity planning techniques can be applied without the operate than dual-stack networks.
indirection or obfuscation of a tunnel.
o 464XLAT has consistent native IP-based monitoring and traffic
engineering. Capacity-planning techniques can be applied without
the indirection or obfuscation of a tunnel.
4. Network Architecture 4. Network Architecture
Examples of 464XLAT architectures are shown in the figures in the Examples of 464XLAT architectures are shown in the figures in the
following sections. following sections.
Wireline Network Architecture can fit in the situations where there Wireline Network Architecture can be used in situations where there
are clients behind the CLAT in the same way regardless of the type of are clients behind the CLAT, regardless of the type of access service
access service, for example FTTH, DOCSIS, or WiFi. -- for example, fiber to the home (FTTH), Data Over Cable Service
Interface Specification (DOCSIS), or WiFi.
Wireless 3GPP Network Architecture fits in the situations where a Wireless 3GPP Network Architecture can be used in situations where a
client terminates the wireless access network and may act as a router client terminates the wireless access network and possibly acts as a
with tethered clients. router with tethered clients.
4.1. Wireline Network Architecture 4.1. Wireline Network Architecture
The private IPv4 host on this diagram can reach global IPv4 hosts via The private IPv4 host in this diagram can reach global IPv4 hosts via
translation on both CLAT and PLAT. On the other hand, the IPv6 host translation on both the CLAT and PLAT. On the other hand, the IPv6
can reach other IPv6 hosts on the Internet directly without host can reach other IPv6 hosts on the Internet directly without
translation. This means that the CPE/CLAT can not only have the translation. This means that the Customer Premises Equipment (CPE) /
function of a CLAT but also the function of an IPv6 native router for CLAT can not only have the function of a CLAT but also the function
native IPv6 traffic. The v4p host behind the CLAT on this diagram of an IPv6 native router for native IPv6 traffic. In this diagram,
has [RFC1918] addresses. the v4p host behind the CLAT has [RFC1918] addresses.
+------+ +------+
| v6 | | v6 |
| host | | host |
+--+---+ +--+---+
| |
.---+---. .---+---.
/ \ / \
/ IPv6 \ / IPv6 \
| Internet | | Internet |
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v6 : Global IPv6 v6 : Global IPv6
v4p : Private IPv4 v4p : Private IPv4
v4g : Global IPv4 v4g : Global IPv4
Figure 1: Wireline Network Topology Figure 1: Wireline Network Topology
4.2. Wireless 3GPP Network Architecture 4.2. Wireless 3GPP Network Architecture
The CLAT function on the User Equipment (UE) provides an [RFC1918] The CLAT function on the User Equipment (UE) provides an [RFC1918]
address and IPv4 default route to the local node network stack. The address and IPv4 default route to the local node's network stack.
applications on the UE can use the private IPv4 address for reaching The applications on the UE can use the private IPv4 address for
global IPv4 hosts via translation on both the CLAT and the PLAT. On reaching global IPv4 hosts via translation on both the CLAT and the
the other hand, reaching IPv6 hosts (including host presented via PLAT. On the other hand, reaching IPv6 hosts (including hosts
DNS64 [RFC6147]) does not require the CLAT function on the UE. presented via DNS64 [RFC6147]) does not require the CLAT function on
the UE.
Presenting a private IPv4 network for tethering via NAT44 and Presenting a private IPv4 network for tethering via NAT44 and
stateless translation on the UE is also an application of the CLAT. stateless translation on the UE is also an application of the CLAT.
+------+ +------+
| v6 | | v6 |
| host | | host |
+--+---+ +--+---+
| |
.---+---. .---+---.
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growth is no longer tightly coupled to the availability of scarce growth is no longer tightly coupled to the availability of scarce
IPv4 addresses. IPv4 addresses.
If another ISP operates the PLAT, the edge ISP is only required to If another ISP operates the PLAT, the edge ISP is only required to
deploy an IPv6 access network. All ISPs do not need IPv4 access deploy an IPv6 access network. All ISPs do not need IPv4 access
networks. They can migrate their access network to a simple and networks. They can migrate their access network to a simple and
highly scalable IPv6-only environment. highly scalable IPv6-only environment.
5.2. Wireless 3GPP Network Applicability 5.2. Wireless 3GPP Network Applicability
At the time of writing, in February 2013, the vast majority of mobile At the time of writing, in April 2013, the vast majority of mobile
networks are compliant to Pre-Release 9 3GPP standards. In Pre- networks are compliant to Pre-Release 9 3GPP standards. In Pre-
Release 9 3GPP networks, Global System for Mobile Communications Release 9 3GPP networks, Global System for Mobile Communications
(GSM) and Universal Mobile Telecommunications System (UMTS) networks (GSM) and Universal Mobile Telecommunications System (UMTS) networks
must signal and support both IPv4 and IPv6 Packet Data Protocol (PDP) must signal and support both IPv4 and IPv6 Packet Data Protocol (PDP)
attachments to access IPv4 and IPv6 network destinations [RFC6459]. attachments to access IPv4 and IPv6 network destinations [RFC6459].
Since there are two PDPs required to support two address families, Since there are two PDPs required to support two address families,
this is double the number of PDPs required to support the status quo this is double the number of PDPs required to support the status quo
of one address family, which is IPv4. of one address family, which is IPv4.
For the cases of connecting to an IPv4 literal or IPv4 socket that For the cases of connecting to an IPv4 literal or IPv4 socket that
require IPv4 connectivity, the CLAT function on the UE provides a require IPv4 connectivity, the CLAT function on the UE provides a
private IPv4 address and IPv4 default route on the host for the private IPv4 address and IPv4 default route on the host for the
applications to reference and bind to. Connections sourced from the applications to reference and bind to. Connections sourced from the
IPv4 interface are immediately routed to the CLAT function and passed IPv4 interface are immediately routed to the CLAT function and passed
to the IPv6-only mobile network, destined for the PLAT. In summary, to the IPv6-only mobile network, destined for the PLAT. In summary,
the UE has the CLAT function that does a stateless translation the UE performs the CLAT function that does a stateless translation
[RFC6145], but only when required by an IPv4-only scenario such as [RFC6145], but only when required by an IPv4-only scenario such as
IPv4 literals or IPv4-only sockets. The mobile network has a PLAT IPv4 literals or IPv4-only sockets. The mobile network has a PLAT
that does stateful translation [RFC6146]. that does stateful translation [RFC6146].
464XLAT works with today's existing systems as much as possible. 464XLAT works with today's existing systems as much as possible.
464XLAT is compatible with existing network based deep packet 464XLAT is compatible with existing solutions for network-based deep
inspection solutions like 3GPP standardized Policy and Charging packet inspection like 3GPP standardized Policy and Charging Control
Control (PCC) [TS.23203]. (PCC) [TS.23203].
6. Implementation Considerations 6. Implementation Considerations
6.1. IPv6 Address Format 6.1. IPv6 Address Format
The IPv6 address format in 464XLAT is defined in Section 2.2 of The IPv6 address format in 464XLAT is defined in Section 2.2 of
[RFC6052]. [RFC6052].
6.2. IPv4/IPv6 Address Translation Chart 6.2. IPv4/IPv6 Address Translation Chart
This chart offers an explanation about address translation This chart offers an explanation about address translation
architecture using a combination of stateful translation at the PLAT architecture using a combination of stateful translation at the PLAT
and stateless translation at the CLAT. The client on this chart is and stateless translation at the CLAT. The client on this chart is
delegated an IPv6 prefix from a prefix delegation mechanism such as delegated an IPv6 prefix from a prefix delegation mechanism such as
DHCPv6-PD [RFC3633], therefore it has a dedicated IPv6 prefix for DHCPv6 Prefix Delegation (DHCPv6-PD) [RFC3633]; therefore, it has a
translation. dedicated IPv6 prefix for translation.
Destination IPv4 address Destination IPv4 address
+----------------------------+ +----------------------------+
| Global IPv4 address | | Global IPv4 address |
| assigned to IPv4 server | | assigned to IPv4 server |
+--------+ +----------------------------+ +--------+ +----------------------------+
| IPv4 | Source IPv4 address | IPv4 | Source IPv4 address
| server | +----------------------------+ | server | +----------------------------+
+--------+ | Global IPv4 address | +--------+ | Global IPv4 address |
^ | assigned to IPv4 PLAT pool | ^ | assigned to IPv4 PLAT pool |
| +----------------------------+ | +----------------------------+
+--------+ +--------+
| PLAT | Stateful XLATE(IPv4:IPv6=1:n) | PLAT | Stateful XLATE(IPv4:IPv6=1:n)
+--------+ +--------+
^ ^
| |
(IPv6 cloud) (IPv6 cloud)
Destination IPv6 address Destination IPv6 address
+--------------------------------------------------------------+ +--------------------------------------------------------------+
| IPv4-Embedded IPv6 address | | IPv4-embedded IPv6 address |
| defined in Section 2.2 of RFC6052 | | defined in Section 2.2 of RFC 6052 |
+--------------------------------------------------------------+ +--------------------------------------------------------------+
Source IPv6 address Source IPv6 address
+--------------------------------------------------------------+ +--------------------------------------------------------------+
| IPv4-Embedded IPv6 address | | IPv4-embedded IPv6 address |
| defined in Section 2.2 of RFC6052 | | defined in Section 2.2 of RFC 6052 |
+--------------------------------------------------------------+ +--------------------------------------------------------------+
(IPv6 cloud) (IPv6 cloud)
^ ^
| |
+--------+ +--------+
| CLAT | Stateless XLATE(IPv4:IPv6=1:1) | CLAT | Stateless XLATE(IPv4:IPv6=1:1)
+--------+ +--------+
^ Destination IPv4 address ^ Destination IPv4 address
| +----------------------------+ | +----------------------------+
+--------+ | Global IPv4 address | +--------+ | Global IPv4 address |
| IPv4 | | assigned to IPv4 server | | IPv4 | | assigned to IPv4 server |
| client | +----------------------------+ | client | +----------------------------+
+--------+ Source IPv4 address +--------+ Source IPv4 address
+----------------------------+ +----------------------------+
| Private IPv4 address | | Private IPv4 address |
| assigned to IPv4 client | | assigned to IPv4 client |
+----------------------------+ +----------------------------+
Case of enabling only stateless XLATE on CLAT Figure 3: Case of Enabling Only Stateless XLATE on CLAT
6.3. IPv6 Prefix Handling 6.3. IPv6 Prefix Handling
There are two relevant IPv6 prefixes that the CLAT must be aware of. There are two relevant IPv6 prefixes that the CLAT must be aware of.
First, CLAT must know its own IPv6 prefixes. The CLAT should acquire First, CLAT must know its own IPv6 prefixes. The CLAT should acquire
a /64 for the uplink interface, a /64 for all downlink interfaces, a /64 for the uplink interface, a /64 for all downlink interfaces,
and a dedicated /64 prefix for the purpose of sending and receiving and a dedicated /64 prefix for the purpose of sending and receiving
statelessly translated packets. When a dedicated /64 prefix is not statelessly translated packets. When a dedicated /64 prefix is not
available for translation from DHCPv6-PD [RFC3633], the CLAT may available for translation from DHCPv6-PD [RFC3633], the CLAT may
perform NAT44 for all IPv4 LAN packets so that all the LAN originated perform NAT44 for all IPv4 LAN packets so that all the LAN-originated
IPv4 packets appear from a single IPv4 address and are then IPv4 packets appear from a single IPv4 address and are then
statelessly translated to one interface IPv6 address that is claimed statelessly translated to one interface IPv6 address that is claimed
by the CLAT via NDP and defended with DAD. by the CLAT via the Neighbor Discovery Protocol (NDP) and defended
with Duplicate Address Detection (DAD).
Second, the CLAT must discover the PLAT-side translation IPv6 prefix Second, the CLAT must discover the PLAT-side translation IPv6 prefix
used as a destination of the PLAT. The CLAT will use this prefix as used as a destination of the PLAT. The CLAT will use this prefix as
the destination of all translation packets that require stateful the destination of all translation packets that require stateful
translation to the IPv4 Internet. It may discover the PLAT-side translation to the IPv4 Internet. It may discover the PLAT-side
translation prefix using [I-D.ietf-behave-nat64-discovery-heuristic]. translation prefix using [Discovery-Heuristic]. In the future, some
In the future some other mechanisms, such as a new DHCPv6 option, other mechanisms, such as a new DHCPv6 option, will possibly be
will possibly be defined to communicate the PLAT-side translation defined to communicate the PLAT-side translation prefix.
prefix.
6.4. DNS Proxy Implementation 6.4. DNS Proxy Implementation
The CLAT should implement a DNS proxy as defined in [RFC5625]. The The CLAT should implement a DNS proxy as defined in [RFC5625]. The
case of an IPv4-only node behind the CLAT querying an IPv4 DNS server case of an IPv4-only node behind the CLAT querying an IPv4 DNS server
is undesirable since it requires both stateful and stateless is undesirable since it requires both stateful and stateless
translation for each DNS lookup. The CLAT should set itself as the translation for each DNS lookup. The CLAT should set itself as the
DNS server via DHCP or other means and proxy DNS queries for IPv4 and DNS server via DHCP or other means and should proxy DNS queries for
IPv6 LAN clients. Using the CLAT enabled home router or UE as a DNS IPv4 and IPv6 LAN clients. Using the CLAT-enabled home router or UE
proxy is a normal consumer gateway function and simplifies the as a DNS proxy is a normal consumer gateway function and simplifies
traffic flow so that only IPv6 native queries are made across the the traffic flow so that only IPv6 native queries are made across the
access network. DNS queries from the client that are not sent to the access network. DNS queries from the client that are not sent to the
DNS proxy on the CLAT must be allowed and are translated and DNS proxy on the CLAT must be allowed and are translated and
forwarded just like any other IP traffic. forwarded just like any other IP traffic.
6.5. CLAT in a Gateway 6.5. CLAT in a Gateway
The CLAT feature can be implemented in a common home router or mobile The CLAT feature can be implemented in a common home router or mobile
phone that has a tethering feature. Routers with a CLAT feature phone that has a tethering feature. Routers with a CLAT feature
should also provide common router services such as DHCP of [RFC1918] should also provide common router services such as DHCP of [RFC1918]
addresses, DHCPv6, NDP with RA, and DNS service. addresses, DHCPv6, NDP with Router Advertisement, and DNS service.
6.6. CLAT to CLAT communications 6.6. CLAT-to-CLAT Communications
464XLAT is a hub and spoke architecture focused on enabling IPv4-only 464XLAT is a hub and spoke architecture focused on enabling IPv4-only
services over IPv6-only networks. ICE [RFC5245] may be used to services over IPv6-only networks. Interactive Connectivity
support peer-to-peer communication within a 464XLAT network. Establishment (ICE) [RFC5245] may be used to support peer-to-peer
communication within a 464XLAT network.
7. Deployment Considerations 7. Deployment Considerations
7.1. Traffic Engineering 7.1. Traffic Engineering
Even if the ISP for end users is different from the PLAT provider Even if the ISP for end users is different from the PLAT provider
(e.g. another ISP), it can implement traffic engineering (e.g., another ISP), it can implement traffic engineering
independently from the PLAT provider. Detailed reasons are below: independently from the PLAT provider. Detailed reasons are below:
1. The ISP for end users can figure out IPv4 destination address 1. The ISP for end users can figure out the IPv4 destination address
from translated IPv6 packet header, so it can implement traffic from the translated IPv6 packet header, so it can implement
engineering based on IPv4 destination address (e.g. traffic traffic engineering based on the IPv4 destination address (e.g.,
monitoring for each IPv4 destination address, packet filtering traffic monitoring for each IPv4 destination address, packet
for each IPv4 destination address, etc.). The tunneling methods filtering for each IPv4 destination address, etc.). The
do not have such an advantage, without any deep packet inspection tunneling methods do not have such an advantage, without any deep
for processing the inner IPv4 packet of the tunnel packet. packet inspection for processing the inner IPv4 packet of the
tunnel packet.
2. If the ISP for end users can assign an IPv6 prefix greater than 2. If the ISP for end users can assign an IPv6 prefix greater than
/64 to each subscriber, this 464XLAT architecture can separate /64 to each subscriber, this 464XLAT architecture can separate
IPv6 prefix for native IPv6 packets and the XLAT prefixes for the IPv6 prefix for native IPv6 packets and the XLAT prefixes for
IPv4/IPv6 translation packets. Accordingly, it can identify the IPv4/IPv6 translation packets. Accordingly, it can identify the
type of packets ("native IPv6 packets" and "IPv4/IPv6 translation type of packets ("native IPv6 packets" and "IPv4/IPv6 translation
packets"), and implement traffic engineering based on the IPv6 packets") and implement traffic engineering based on the IPv6
prefix. prefix.
7.2. Traffic Treatment Scenarios 7.2. Traffic Treatment Scenarios
The below table outlines how different permutations of connectivity The below table outlines how different permutations of connectivity
are treated in the 464XLAT architecture. are treated in the 464XLAT architecture.
NOTE: 464XLAT double translation treatment will be stateless when a Note: 464XLAT double translation treatment will be stateless when a
dedicated /64 is available for translation on the CLAT. Otherwise, dedicated /64 is available for translation on the CLAT. Otherwise,
the CLAT will have both stateful and stateless since it requires the CLAT will have both stateful and stateless since it requires
NAT44 from the LAN to a single IPv4 address and then stateless NAT44 from the LAN to a single IPv4 address and then stateless
translation to a single IPv6 address. translation to a single IPv6 address.
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| Server | Application | Traffic Treatment | Location of | | Server | Application | Traffic Treatment | Location of |
| | and Host | | Translation | | | and Host | | Translation |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| IPv6 | IPv6 | End-to-end IPv6 | None | | IPv6 | IPv6 | End-to-End IPv6 | None |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| IPv4 | IPv6 | Stateful Translation | PLAT | | IPv4 | IPv6 | Stateful Translation | PLAT |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| IPv4 | IPv4 | 464XLAT | PLAT/CLAT | | IPv4 | IPv4 | 464XLAT | PLAT/CLAT |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
Traffic Treatment Scenarios Traffic Treatment Scenarios
8. Security Considerations 8. Security Considerations
To implement a PLAT, see security considerations presented in Section To implement a PLAT, see the security considerations presented in
5 of [RFC6146]. Section 5 of [RFC6146].
To implement a CLAT, see security considerations presented in Section
7 of [RFC6145]. The CLAT may comply with [RFC6092].
9. IANA Considerations
This document has no actions for IANA. To implement a CLAT, see the security considerations presented in
Section 7 of [RFC6145]. The CLAT may comply with [RFC6092].
10. Acknowledgements 9. Acknowledgements
The authors would like to thank JPIX NOC members, JPIX 464XLAT trial The authors would like to thank JPIX NOC members, JPIX 464XLAT trial
service members, Seiichi Kawamura, Dan Drown, Brian Carpenter, Rajiv service members, Seiichi Kawamura, Dan Drown, Brian Carpenter, Rajiv
Asati, Washam Fan, Behcet Sarikaya, Jan Zorz, Tatsuya Oishi, Lorenzo Asati, Washam Fan, Behcet Sarikaya, Jan Zorz, Tatsuya Oishi, Lorenzo
Colitti, Erik Kline, Ole Troan, Maoke Chen, Gang Chen, Tom Petch, Colitti, Erik Kline, Ole Troan, Maoke Chen, Gang Chen, Tom Petch,
Jouni Korhonen, Bjoern A. Zeeb, Hemant Singh, Vizdal Ales, Mark ZZZ Jouni Korhonen, Bjoern A. Zeeb, Hemant Singh, Vizdal Ales, Mark ZZZ
Smith, Mikael Abrahamsson, Tore Anderson, Teemu Savolainen, Alexandru Smith, Mikael Abrahamsson, Tore Anderson, Teemu Savolainen, Alexandru
Petrescu, Gert Doering, Victor Kuarsingh, Ray Hunter, James Woodyatt, Petrescu, Gert Doering, Victor Kuarsingh, Ray Hunter, James Woodyatt,
Tom Taylor, and Remi Despres for their helpful comments. We also Tom Taylor, and Remi Despres for their helpful comments. We also
would like to thank Fred Baker and Joel Jaeggli for their support. would like to thank Fred Baker and Joel Jaeggli for their support.
11. References 10. References
11.1. Normative References 10.1. Normative References
[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X. [RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X.
Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052, Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052,
October 2010. October 2010.
[RFC6144] Baker, F., Li, X., Bao, C., and K. Yin, "Framework for
IPv4/IPv6 Translation", RFC 6144, April 2011.
[RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation [RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation
Algorithm", RFC 6145, April 2011. Algorithm", RFC 6145, April 2011.
[RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful [RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful
NAT64: Network Address and Protocol Translation from IPv6 NAT64: Network Address and Protocol Translation from IPv6
Clients to IPv4 Servers", RFC 6146, April 2011. Clients to IPv4 Servers", RFC 6146, April 2011.
11.2. Informative References 10.2. Informative References
[I-D.ietf-behave-nat64-discovery-heuristic] [Discovery-Heuristic]
Savolainen, T., Korhonen, J., and D. Wing, "Discovery of Savolainen, T., Korhonen, J., and D. Wing, "Discovery of
the IPv6 Prefix Used for IPv6 Address Synthesis", the IPv6 Prefix Used for IPv6 Address Synthesis", Work
draft-ietf-behave-nat64-discovery-heuristic-13 (work in in Progress, March 2013.
progress), November 2012.
[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and [RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and
E. Lear, "Address Allocation for Private Internets", E. Lear, "Address Allocation for Private Internets",
BCP 5, RFC 1918, February 1996. BCP 5, RFC 1918, February 1996.
[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
Host Configuration Protocol (DHCP) version 6", RFC 3633, Host Configuration Protocol (DHCP) version 6", RFC 3633,
December 2003. December 2003.
[RFC5245] Rosenberg, J., "Interactive Connectivity Establishment [RFC5245] Rosenberg, J., "Interactive Connectivity Establishment
skipping to change at page 13, line 10 skipping to change at page 13, line 7
[RFC6459] Korhonen, J., Soininen, J., Patil, B., Savolainen, T., [RFC6459] Korhonen, J., Soininen, J., Patil, B., Savolainen, T.,
Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation
Partnership Project (3GPP) Evolved Packet System (EPS)", Partnership Project (3GPP) Evolved Packet System (EPS)",
RFC 6459, January 2012. RFC 6459, January 2012.
[TS.23203] 3GPP, "Policy and charging control architecture", 3GPP [TS.23203] 3GPP, "Policy and charging control architecture", 3GPP
TS 23.203 10.7.0, June 2012. TS 23.203 10.7.0, June 2012.
Appendix A. Examples of IPv4/IPv6 Address Translation Appendix A. Examples of IPv4/IPv6 Address Translation
The following is a example of IPv4/IPv6 Address Translation on the The following is an example of IPv4/IPv6 address translation on the
464XLAT architecture. 464XLAT architecture.
In the case that an IPv6 prefix greater than /64 is assigned to an In the case that an IPv6 prefix greater than /64 is assigned to an
end user by such as DHCPv6-PD [RFC3633], the CLAT can use a dedicated end user by such as DHCPv6-PD [RFC3633], the CLAT can use a dedicated
/64 from the assigned IPv6 prefix. /64 from the assigned IPv6 prefix.
Host & configuration value Host & configuration value
+------------------------------+ +------------------------------+
| IPv4 server | | IPv4 server |
| [198.51.100.1] | IP packet header | [198.51.100.1] | IP packet header
skipping to change at page 15, line 8 skipping to change at page 14, line 8
| | [192.168.1.2] | | | [192.168.1.2] |
+------------------------------+ +--------------------------------+ +------------------------------+ +--------------------------------+
| IPv4 client | | IPv4 client |
| [192.168.1.2/24] | | [192.168.1.2/24] |
+------------------------------+ +------------------------------+
Delegated IPv6 prefix for client: 2001:db8:aaaa::/56 Delegated IPv6 prefix for client: 2001:db8:aaaa::/56
Authors' Addresses Authors' Addresses
Masataka Mawatari Masataka Mawatari
Japan Internet Exchange Co.,Ltd. Japan Internet Exchange Co., Ltd.
KDDI Otemachi Building 19F, 1-8-1 Otemachi, KDDI Otemachi Building 19F, 1-8-1 Otemachi,
Chiyoda-ku, Tokyo 100-0004 Chiyoda-ku, Tokyo 100-0004
JAPAN JAPAN
Phone: +81 3 3243 9579 Phone: +81 3 3243 9579
Email: mawatari@jpix.ad.jp EMail: mawatari@jpix.ad.jp
Masanobu Kawashima Masanobu Kawashima
NEC AccessTechnica, Ltd. NEC AccessTechnica, Ltd.
800, Shimomata 800, Shimomata
Kakegawa-shi, Shizuoka 436-8501 Kakegawa-shi, Shizuoka 436-8501
JAPAN JAPAN
Phone: +81 537 22 8274 Phone: +81 537 22 8274
Email: kawashimam@vx.jp.nec.com EMail: kawashimam@vx.jp.nec.com
Cameron Byrne Cameron Byrne
T-Mobile USA T-Mobile USA
Bellevue, Washington 98006 Bellevue, Washington 98006
USA USA
Email: cameron.byrne@t-mobile.com EMail: cameron.byrne@t-mobile.com
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