draft-ietf-v6ops-464xlat-03.txt   draft-ietf-v6ops-464xlat-04.txt 
Internet Engineering Task Force M. Mawatari Internet Engineering Task Force M. Mawatari
Internet-Draft Japan Internet Exchange Co.,Ltd. Internet-Draft Japan Internet Exchange Co.,Ltd.
Intended status: BCP M. Kawashima Intended status: BCP M. Kawashima
Expires: November 9, 2012 NEC AccessTechnica, Ltd. Expires: December 27, 2012 NEC AccessTechnica, Ltd.
C. Byrne C. Byrne
T-Mobile USA T-Mobile USA
May 8, 2012 June 25, 2012
464XLAT: Combination of Stateful and Stateless Translation 464XLAT: Combination of Stateful and Stateless Translation
draft-ietf-v6ops-464xlat-03 draft-ietf-v6ops-464xlat-04
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 RFC 6146 in the
core and stateless protocol translation RFC 6145 at the edge. 464XLAT core and stateless protocol translation RFC 6145 at the edge. 464XLAT
is a simple and scalable technique to quickly deploy limited IPv4 is a simple and scalable technique to quickly deploy limited IPv4
access service to mobile and wireline IPv6-only edge networks without access service to IPv6-only edge networks without encapsulation.
encapsulation.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on November 9, 2012. This Internet-Draft will expire on December 27, 2012.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Motivation and Uniqueness of 464XLAT . . . . . . . . . . . . . 4 4. Motivation and Uniqueness of 464XLAT . . . . . . . . . . . . . 4
5. Network Architecture . . . . . . . . . . . . . . . . . . . . . 5 5. Network Architecture . . . . . . . . . . . . . . . . . . . . . 4
5.1. Wireline Network Architecture . . . . . . . . . . . . . . 6 5.1. Wireline Network Architecture . . . . . . . . . . . . . . 4
5.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 7 5.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 5
6. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 7 6. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Wireline Network Applicability . . . . . . . . . . . . . . 7 6.1. Wireline Network Applicability . . . . . . . . . . . . . . 6
6.2. Wireless 3GPP Network Applicability . . . . . . . . . . . 8 6.2. Wireless 3GPP Network Applicability . . . . . . . . . . . 7
7. Implementation Considerations . . . . . . . . . . . . . . . . 9 7. Implementation Considerations . . . . . . . . . . . . . . . . 7
7.1. IPv6 Address Format . . . . . . . . . . . . . . . . . . . 9 7.1. IPv6 Address Format . . . . . . . . . . . . . . . . . . . 7
7.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 9 7.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 7
7.3. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 10 7.2.1. Case of enabling only stateless XLATE on CLAT . . . . 7
7.4. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 11 7.2.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 9
7.5. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 11 7.3. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 11
7.6. Relationship between CLAT and NAT44 . . . . . . . . . . . 11 7.3.1. Case of enabling only stateless XLATE on CLAT . . . . 11
7.7. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 11 7.3.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 11
7.8. CLAT to CLAT communications . . . . . . . . . . . . . . . 12 7.4. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 12
8. Deployment Considerations . . . . . . . . . . . . . . . . . . 12 7.5. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 12
9. Security Considerations . . . . . . . . . . . . . . . . . . . 12 7.6. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 12
7.7. CLAT to CLAT communications . . . . . . . . . . . . . . . 12
8. Deployment Considerations . . . . . . . . . . . . . . . . . . 13
9. Security Considerations . . . . . . . . . . . . . . . . . . . 13
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
12.1. Normative References . . . . . . . . . . . . . . . . . . . 13 12.1. Normative References . . . . . . . . . . . . . . . . . . . 14
12.2. Informative References . . . . . . . . . . . . . . . . . . 13 12.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 Appendix A. Examples of IPv4/IPv6 Address Translation . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction 1. Introduction
The IANA unallocated IPv4 address pool was exhausted on February 3, The IANA unallocated IPv4 address pool was exhausted on February 3,
2011. Each RIR's unallocated IPv4 address pool will exhaust in the 2011. Each RIR's unallocated IPv4 address pool will exhaust in the
near future. It will be difficult for many networks to assign IPv4 near future. It will be difficult for many networks to assign IPv4
addresses to end users, despite substantial IP connectivity growth addresses to end users, despite substantial IP connectivity growth
required for mobile devices, smart-grid, and cloud nodes. required for fast growing edge networks.
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 IPv4 service is limited to application functionality. The 464XLAT architecture only supports IPv4 in the
that function in a client server model and is not fit for IPv4 peer- client server model, where the server has global IPv4 address. This
to-peer communication or inbound IPv4 connections. means it is not fit for IPv4 peer-to-peer communication or inbound
IPv4 connections. 464XLAT builds on IPv6 transport and 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 a host may simply send IPv4 packets, require DNS64 [RFC6147] since an IPv4 host may simply send IPv4
including packets to an IPv4 DNS server, which will be translated on packets, including packets to an IPv4 DNS server, which will be
the CLAT to IPv6 and back to IPv4 on the PLAT. 464XLAT networks may translated on the CLAT to IPv6 and back to IPv4 on the PLAT. 464XLAT
use DNS64 to enable single stateful translation [RFC6146] instead of networks may use DNS64 [RFC6147] to enable single stateful
464XLAT double translation where possible. It is also possible to translation [RFC6146] instead of 464XLAT double translation where
provide single IPv4/IPv6 translation service, which will be needed in possible. The 464XLAT architecture encourages IPv6 transition by
the future case of IPv6-only servers and peers to be reached from making IPv4 services reachable across IPv6-only networks and
legacy IPv4-only hosts. The 464XLAT architecture encourages IPv6 providing IPv6 and IPv4 connectivity to single-stack IPv4 or IPv6
transition by making IPv4 services reachable across IPv6-only servers and peers.
networks and providing IPv6 and IPv4 connectivity to single-stack
IPv4 or IPv6 servers and peers.
Running a single-stack IPv6-only network has several operational By combining 464XLAT with BIH [RFC6535], it is also possible to
benefits in terms of increasing scalability and decreasing provide single IPv4 to IPv6 translation service, which will be needed
operational complexity. Unfortunately, there are important cases in the future case of IPv6-only servers and peers to be reached from
where IPv6-only networks fail to meet subscriber expectations, as legacy IPv4-only hosts across IPv6-only networks.
described in [RFC6586]. The 464XLAT overcomes the issues described
in [RFC6586] to provide subscribers the full IPv6 and limited IPv4
functionality while providing the network operator the benefits of a
simple yet highly scalable single-stack IPv6 network.
2. Requirements Language 2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
3. Terminology 3. 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 packets to global [RFC6146]. It translates N:1 global IPv6 packets to global
IPv4 packets, and vice versa. IPv4 packets, 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
packets to global IPv6 packets, and vice versa. The CLAT packets to global IPv6 packets, 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. CLAT SHOULD perform router function to mobile phone. CLAT SHOULD perform router function to
facilitate packets forwarding through the stateless facilitate packets forwarding through the stateless
skipping to change at page 4, line 17 skipping to change at page 4, line 14
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 packets to global [RFC6146]. It translates N:1 global IPv6 packets to global
IPv4 packets, and vice versa. IPv4 packets, 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
packets to global IPv6 packets, and vice versa. The CLAT packets to global IPv6 packets, 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. CLAT SHOULD perform router function to mobile phone. CLAT SHOULD perform router function to
facilitate packets forwarding through the stateless facilitate packets forwarding through the stateless
translation even if it is an end-node. In addition to translation even if it is an end-node. In the case where the
stateless translation, the CLAT as a common home router or 3G access network does not allow for a dedicated IPv6 prefix for
router is expected to perform gateway functions such as DHCP translation, a NAT44 SHOULD be used between the router
server and DNS proxy for local clients. function and the stateless translator function. The CLAT as
a common home router or 3G router is expected to perform
UE: The 3GPP term for user equipment. The most common type of UE gateway functions such as DHCP server and DNS proxy for local
is a mobile phone. clients. The CLAT does not comply with the sentence "Both
IPv4-translatable IPv6 addresses and IPv4-converted IPv6
PDP: A Packet Data Protocol (PDP) Context is the equivalent of a addresses SHOULD use the same prefix." that is described on
virtual connection between the host and a gateway. Section 3.3 in [RFC6052] due to using different IPv6 prefixes
for CLAT-side and PLAT-side IPv4 addresses.
4. Motivation and Uniqueness of 464XLAT 4. Motivation and Uniqueness of 464XLAT
1. Minimal IPv4 resource requirements, maximum IPv4 efficiency 1. Minimal IPv4 resource requirements, maximum IPv4 efficiency
through statistical multiplexing
464XLAT has low barriers to entry since only a small amount of
IPv4 addresses are needed to support the stateful translation
[RFC6146] function in the PLAT. With port-overloading, one IPv4
address can support millions of simultaneous translations.
Given that network operators are deploying IPv6-only access
networks because IPv4 resources are scarce, solutions that
require dual-stack (no IPv4 multiplexing) or stateless address
sharing (bounded static address multiplexing) are simply not
IPv4-efficient enough to solve the two-pronged challenge of
increasing IPv4 address scarcity and continued exponential
network edge growth for network operators.
2. No new protocols required, quick deployment 2. No new protocols required, quick deployment
464XLAT can be deployed today, it uses existing RFCs ([RFC6145] 3. IPv6-only networks are simpler and therefore less expensive to
and [RFC6146]), and there exists implementations for both operate
wireline networks (CLAT in the home router) and wireless 3GPP
networks (CLAT in the UE). The ability to quickly deploy 464XLAT
is a critical feature given the urgency of IPv4 exhaustion and
brisk pace of internet growth.
3. Cost-effective transition to IPv6
When combined with DNS64 [RFC6147], the 464XLAT architecture only
requires double translation in the case of IPv4-referrals or
IPv4-only socket calls. Consequently, the network traffic in the
ISP backbone network is predominately IPv6 end-to-end or single
translation. This is especially cost-effective in wireless 3GPP
GSM and UMTS networks that would otherwise require two separate
PDP connections to support IPv4 and IPv6.
While translation on the CLAT is not always used, the CLAT
function is crucial for enabling the IPv4-only applications. All
IPv6-native flows pass end-to-end without any translation. This
is a beneficial solution for end-users, content providers, and
network operators that scale best with end-to-end IPv6
communication.
In summary, the 464XLAT architecture works today for service
providers that require large-scale strategic IPv6 deployments to
overcome the challenges of IPv4 address scarcity. Since 464XLAT is
stateful, there is no tight coupling or IPv4 address coordination
between the PLAT and the CLAT. Unlike other transition architectures
associated with tunneling or
[I-D.mdt-softwire-mapping-address-and-port], 464XLAT assumes that
IPv4 is scarce and IPv6 must work with today's existing systems as
much as possible. In the case of tunneling, the tunneling solutions
like Dual-Stack Lite [RFC6333] are known to break existing network
based deep packet inspection solutions like 3GPP standardized Policy
and Charging Control (PCC). 464XLAT does not require much IPv4
address space to enable the stateful translation [RFC6146] function
in the PLAT while providing global IPv4 and IPv6 reachability to
IPv6-only wireline and wireless subscribers.
5. Network Architecture 5. Network Architecture
464XLAT architecture is shown in the following figure. 464XLAT architecture is shown in the following figure.
5.1. Wireline Network Architecture 5.1. Wireline Network Architecture
The private IPv4 host on this diagram can reach global IPv4 hosts via
translation on both CLAT and PLAT. On the other hand, the IPv6 host
can reach other IPv6 hosts on the Internet directly without
translation. This means that the CPE can not only have the function
of CLAT but also the function of IPv6 native router for IPv6 native
traffic.
---- ----
| v6 | | v6 |
---- ----
| |
---- | .---+---. .------. ---- | .---+---. .------.
| v6 |-----+ / \ / \ | v6 |-----+ / \ / \
---- | ------ / IPv6 \ ------ / IPv4 \ ---- | ------ / IPv6 \ ------ / IPv4 \
+---| CLAT |---+ Internet +---| PLAT |---+ Internet | +---| CLAT |---+ Internet +---| PLAT |---+ Internet |
------- | ------ \ / ------ \ / ------- | ------ \ / ------ \ /
|v4p/v6 |--+ `---------' `----+----' |v4p/v6 |--+ `---------' `----+----'
skipping to change at page 7, line 7 skipping to change at page 5, line 30
<- v4p -> XLAT <--------- v6 --------> XLAT <- v4g -> <- v4p -> XLAT <--------- v6 --------> XLAT <- v4g ->
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
5.2. Wireless 3GPP Network Architecture 5.2. Wireless 3GPP Network Architecture
The CLAT function on the UE provides an [RFC1918] address and IPv4
default route. The applications on the UE can use the private IPv4
address for reaching global IPv4 hosts via translation on both CLAT
and PLAT. On the other hand, reaching IPv6 hosts (including host
presented via DNS64 [RFC6147]) does not require the CLAT function on
the UE.
---- ----
| v6 | | v6 |
---- ----
| |
.---+---. .---+---.
/ \ / \
/ IPv6 \ / IPv6 \
| Internet | | Internet |
\ / \ /
UE / Mobile Phone `---------' UE / Mobile Phone `---------'
+----------------------+ | +----------------------+ |
| ---- | | .---+---. .------. | ---- | | .---+---. .------.
| | v6 |----+ | / \ / \ | | v6 |----+ | / \ / \
| ---- | ------| / IPv6 PDP \ ------ / IPv4 \ | ---- | ------| / IPv6 PDP \ ------ / IPv4 \
| +---| CLAT |---+ Mobile Core +---| PLAT |--+ Internet | | +---| CLAT |---+ Mobile Core +---| PLAT |--+ Internet |
| | ------| \ GGSN / ------ \ / | | ------| \ GGSN / ------ \ /
| | | \ ' `----+---' | | | \ ' `----+---'
| ------ | | `-------' | | ------ | | `-------' |
| | v4p |---+ | ----- | | v4p |---+ | -----
| ------ | | | v4g | | ------ | | | v4g |
skipping to change at page 7, line 41 skipping to change at page 6, line 39
v6 : Global IPv6 v6 : Global IPv6
v4p : Private IPv4 v4p : Private IPv4
v4g : Global IPv4 v4g : Global IPv4
Figure 2: Wireless 3GPP Network Topology Figure 2: Wireless 3GPP Network Topology
6. Applicability 6. Applicability
6.1. Wireline Network Applicability 6.1. Wireline Network Applicability
When an ISP has IPv6 access network infrastructure and 464XLAT, the When an ISP has IPv6 464XLAT, the ISP can provide outgoing IPv4
ISP can provide IPv4 service to end users across an IPv6 access service to end users across an IPv6 access network. The result is
network. The result is that edge network growth is no longer tightly that edge network growth is no longer tightly coupled to the
coupled to the availability of scarce IPv4 addresses. availability of scarce IPv4 addresses.
If the IXP or another provider operates the PLAT, the ISP is only If the IXP or another provider operates the PLAT, the edge ISP is
required to deploy an IPv6 access network. All ISPs do not need IPv4 only required to deploy an IPv6 access network. All ISPs do not need
access networks. They can migrate their access network to a simple IPv4 access networks. They can migrate their access network to a
and highly scalable IPv6-only environment. Incidentally, Japan simple and highly scalable IPv6-only environment.
Internet Exchange(JPIX) is providing 464XLAT trial service since July
2010. In addition to this, the effectiveness of 464XLAT was
confirmed in the WIDE camp Spring 2012. The result is described in
[I-D.hazeyama-widecamp-ipv6-only-experience].
6.2. Wireless 3GPP Network Applicability Incidentally, the effectiveness of 464XLAT was confirmed in the WIDE
camp Spring 2012. The result is described in
The vast majority of mobile wireless networks are compliant to Pre- [I-D.hazeyama-widecamp-ipv6-only-experience].
Release 9 3GPP standards. In Pre-Release 9 3GPP networks, GSM and
UMTS networks must signal and support both IPv4 and IPv6 PDP
attachments to access IPv4 and IPv6 network destinations. Since
there are 2 PDPs required to support 2 address families, this is
double the number of PDPs required to support the status quo of 1
address family, which is IPv4. Doubling the PDP count to support
IPv4 and IPv6 is generally not operationally viable since a large
portion of the network cost is derived from the number of PDP
attachments, both in terms of licenses from the network hardware
vendors and in terms of actual hardware resources required to support
and maintain the PDP signaling and mobility events. Doubling the
number of PDP attachments has been one of the major barriers to
introducing IPv6 in mobile networks. Dual-stack IPv4 and IPv6 simply
costs more from the network provider perspective and does not result
in any new revenues. In 3GPP Release 9 and forward, 2 PDPs are no
longer required but the scarcity of IPv4 addresses remain.
Now that both global and private IPv4 addresses are scarce to the 6.2. Wireless 3GPP Network Applicability
extent that it is a substantial business risk and limiting growth in
many areas, the mobile network providers must support IPv6 to solve
the IP address scarcity issue. It is not feasible to simply turn on
additional IPv6 PDP network attachments since that does not solve the
near-term IPv4 scarcity issues and it increases cost in most cases.
The most logical path forward is to replace IPv4 with IPv6 and
replace the common NAT44 with stateful translation [RFC6146] and
DNS64 [RFC6147]. Extensive live network testing with hundreds of
friendly-users has shown that IPv6-only network attachments for
mobile devices supports over 85% of the common applications on the
Android mobile operating systems. The remaining 15% of applications
do not work because the application requires an IPv4 socket or the
application does an IPv4-referral. These findings are consistent
with the mobile IPv6-only user experience in [RFC6586].
464XLAT in combination with stateful translation [RFC6146] and DNS64 464XLAT in combination with stateful translation [RFC6146] and DNS64
[RFC6147] allows 85% of the Android applications to continue to work [RFC6147] allows 85% of the Android applications to continue to work
with single translation or native IPv6 access. For the remaining 15% with single translation or native IPv6 access. For the remaining 15%
of applications that require IPv4 connectivity, the CLAT function on of applications that require IPv4 connectivity, the CLAT function on
the UE provides a private IPv4 address and IPv4 default-route on the the UE provides a private IPv4 address and IPv4 default-route on the
host for the applications to reference and bind to. Connections host for the applications to reference and bind to. Connections
sourced from the IPv4 interface are immediately routed to the CLAT sourced from the IPv4 interface are immediately routed to the CLAT
function and passed to the IPv6-only mobile network, destine to the function and passed to the IPv6-only mobile network, destine to the
PLAT. In summary, the UE has the CLAT function that does a stateless PLAT. In summary, the UE has the CLAT function that does a stateless
skipping to change at page 9, line 18 skipping to change at page 7, line 30
7. Implementation Considerations 7. Implementation Considerations
7.1. IPv6 Address Format 7.1. IPv6 Address Format
IPv6 address format in 464XLAT is defined in Section 2.2 of IPv6 address format in 464XLAT is defined in Section 2.2 of
[RFC6052]. [RFC6052].
7.2. IPv4/IPv6 Address Translation Chart 7.2. IPv4/IPv6 Address Translation Chart
IPv4/IPv6 address translation chart is shown in the following figure. 7.2.1. Case of enabling only stateless XLATE on CLAT
This case should be used when a prefix delegation mechanism such as
DHCPv6-PD [RFC3633] is available to assign a dedicated translation
prefix to the CLAT.
Source IPv4 address Source IPv4 address
+----------------------------+ +----------------------------+
| Global IPv4 address | | Global IPv4 address |
| assigned to IPv4 pool@PLAT | | assigned to IPv4 pool@PLAT |
+--------+ +----------------------------+ +--------+ +----------------------------+
| IPv4 | Destination IPv4 address | IPv4 | Destination IPv4 address
| server | +----------------------------+ | server | +----------------------------+
+--------+ | Global IPv4 address | +--------+ | Global IPv4 address |
^ | assigned to IPv4 server | ^ | assigned to IPv4 server |
skipping to change at page 9, line 48 skipping to change at page 8, line 33
| defined in Section 2.2 of RFC6052 | | defined in Section 2.2 of RFC6052 |
+--------------------------------------------------------------+ +--------------------------------------------------------------+
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 RFC6052 |
+--------------------------------------------------------------+ +--------------------------------------------------------------+
(IPv6 cloud) (IPv6 cloud)
^ ^
| |
+--------+
| | In the case CLAT has a
| | dedicated IPv6 prefix for
| CLAT | translation, the CLAT behaves
| | with only Stateless XLATE
| | (IPv4:IPv6=1:1).
+--------+
^ Source IPv4 address
| +----------------------------+
+--------+ | Private IPv4 address |
| IPv4 | | assigned to IPv4 client |
| client | +----------------------------+
+--------+ Destination IPv4 address
+----------------------------+
| Global IPv4 address |
| assigned to IPv4 server |
+----------------------------+
Case of enabling only stateless XLATE on CLAT
7.2.2. Case of enabling NAT44 and stateless XLATE on CLAT
This case should be used when a prefix delegation mechanism is not
available to assign a dedicated translation prefix to the CLAT. In
this case, NAT44 SHOULD be used so that all IPv4 source addresses are
mapped to a single IPv6 address.
Source IPv4 address
+----------------------------+
| Global IPv4 address |
| assigned to IPv4 pool@PLAT |
+--------+ +----------------------------+
| IPv4 | Destination IPv4 address
| server | +----------------------------+
+--------+ | Global IPv4 address |
^ | assigned to IPv4 server |
| +----------------------------+
+--------+
| PLAT | Stateful XLATE(IPv4:IPv6=1:n)
+--------+
^
| |
Source IPv6 address (IPv6 cloud)
+--------------------------------------------------------------+
| IPv4-Embedded IPv6 address |
| defined in Section 2.2 of RFC6052 |
+--------------------------------------------------------------+
Destination IPv6 address
+--------------------------------------------------------------+
| IPv4-Embedded IPv6 address |
| defined in Section 2.2 of RFC6052 |
+--------------------------------------------------------------+
(IPv6 cloud)
^
| |
+--------+ +--------+
| | Case 1: CLAT will have a | | In the case CLAT does not have
| | dedicated IPv6 prefix | | a dedicated IPv6 prefix for
| | -> Stateless XLATE | CLAT | translation, the CLAT behaves
| | (IPv4:IPv6=1:1) | | with NAT44 and Stateless XLATE
| CLAT | | | (IPv4:IPv6=1:1).
| | Case 2: CLAT will not have a
| | dedicated IPv6 prefix
| | -> NAT44 -> Stateless XLATE
| | (IPv4:IPv6=1:1)
+--------+ +--------+
^ Source IPv4 address ^ Source IPv4 address
| +----------------------------+ | +----------------------------+
+--------+ | Private IPv4 address | +--------+ | Private IPv4 address |
| IPv4 | | assigned to IPv4 client | | IPv4 | | assigned to IPv4 client |
| client | +----------------------------+ | client | +----------------------------+
+--------+ Destination IPv4 address +--------+ Destination IPv4 address
+----------------------------+ +----------------------------+
| Global IPv4 address | | Global IPv4 address |
| assigned to IPv4 server | | assigned to IPv4 server |
+----------------------------+ +----------------------------+
IPv4/IPv6 Address Translation Chart Case of enabling NAT44 and stateless XLATE on CLAT
7.3. Traffic Treatment Scenarios 7.3. IPv6 Prefix Handling
7.3.1. Case of enabling only stateless XLATE on CLAT
From the delegated DHCPv6 [RFC3633] prefix, a /64 is dedicated to
source and receive IPv6 packets associated with the stateless
translation [RFC6145].
The CLAT MAY discover the Pref64::/n of the PLAT via some method such
as DHCPv6 option, TR-069, DNS APL RR [RFC3123] or
[I-D.ietf-behave-nat64-discovery-heuristic].
7.3.2. Case of enabling NAT44 and stateless XLATE on CLAT
In the case that DHCPv6-PD [RFC3633] is not available, the CLAT does
not have dedicated IPv6 prefix for translation. If the CLAT does not
have a dedicated IPv6 prefix for translation, the CLAT performs with
NAT44 and stateless translation [RFC6145].
Incoming source IPv4 packets from the LAN of [RFC1918] addresses are
NAT44 to the CLAT IPv4 host address. Then, the CLAT will do a
stateless translation [RFC6145] so that the IPv4 packets from the
CLAT IPv4 host address are translated to the CLAT WAN IPv6 address as
described in [RFC6052].
Its subnet prefix is made of the delegated prefix, completed if
needed to a /64 by a subnet ID = 0. Its interface ID is the 464XLAT
interface ID (Section 10).
The CLAT MAY discover the Pref64::/n of the PLAT via some method such
as TR-069, DNS APL RR [RFC3123] or
[I-D.ietf-behave-nat64-discovery-heuristic].
7.4. Traffic Treatment Scenarios
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| 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 |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| IPv6 | IPv4 | Stateless Translation | CLAT | | IPv6 | IPv4 | Stateless Translation | CLAT |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
Traffic Treatment Scenarios Traffic Treatment Scenarios
The above chart shows most common traffic types and traffic The above chart shows most common traffic types and traffic
treatment. treatment.
7.4. DNS Proxy Implementation 7.5. 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 CLAT querying an IPv4 DNS server is case of an IPv4-only node behind CLAT querying an IPv4 DNS server is
undesirable since it requires both stateful and stateless translation undesirable since it requires both stateful and stateless translation
for each DNS lookup. The CLAT SHOULD set itself as the DNS server 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 IPv6 via DHCP or other means and proxy DNS queries for IPv4 and IPv6
clients. Using the CLAT enabled home router or UE as a DNS proxy is clients. Using the CLAT enabled home router or UE as a DNS proxy is
a normal consume gateway function and simplifies the traffic flow so a normal consume gateway function and simplifies the traffic flow so
that only IPv6 native queries are made across the access network. that only IPv6 native queries are made across the access network.
The CLAT SHOULD allow for a client to query any DNS server of its The CLAT SHOULD allow for a client to query any DNS server of its
choice and bypass the proxy. choice and bypass the proxy.
7.5. IPv6 Prefix Handling 7.6. CLAT in a Gateway
From the delegated DHCPv6 [RFC3633] prefix, a /64 is dedicated to
source and receive IPv6 packets associated with the stateless
translation [RFC6145].
In another cases where the access network does not allow for a
dedicated translation prefix, the CLAT will do NAT44 such that all
private IPv4 sourced LAN packets appears from one private IPv4
address which is statelessly translated to one IPv6 address.
The CLAT MAY discover the Pref64::/n of the PLAT via some method such
as DHCPv6 option, TR-069, DNS APL RR [RFC3123] or
[I-D.ietf-behave-nat64-discovery-heuristic].
7.6. Relationship between CLAT and NAT44
If the CLAT does not have dedicated IPv6 prefix for translation, the
CLAT does NAT44 as an internal function which never appears on the
wire.
Incoming source IPv4 packets from the LAN of [RFC1918] addresses are
NAT44 to the CLAT host address on the LAN of one [RFC1918] address.
Then, the CLAT will do a stateless translation [RFC6145] so that the
IPv4 packets from one [RFC1918] address are translated to the CLAT
LAN IPv6 address as described in [RFC6052].
7.7. CLAT in a Gateway
The CLAT is a stateless translation feature which can be implemented The CLAT is a stateless translation feature which can be implemented
in a common home router or mobile phone that has a mobile router in a common home router or mobile phone that has a mobile router
feature. The router with CLAT function SHOULD provide common router feature. The router with CLAT function SHOULD provide common router
services such as DHCP of [RFC1918] addresses, DHCPv6, and DNS services such as DHCP of [RFC1918] addresses, DHCPv6, and DNS
service. The router SHOULD set itself as the DNS server advertised service. The router SHOULD set itself as the DNS server advertised
via DHCP or other means to the clients so that it may implement the via DHCP or other means to the clients so that it may implement the
DNS proxy function to avoid double translation of DNS request. DNS proxy function to avoid double translation of DNS request.
7.8. CLAT to CLAT communications 7.7. CLAT to CLAT communications
While CLAT to CLAT IPv4 communication may work when the client IPv4 While CLAT to CLAT IPv4 communication may work when the client IPv4
subnets do not overlap, this traffic flow is out of scope. 464XLAT is subnets do not overlap, this traffic flow is out of scope. 464XLAT is
a hub and spoke architecture focused on enabling IPv4-only services a hub and spoke architecture focused on enabling IPv4-only services
over IPv6-only access networks. over IPv6-only access networks.
8. Deployment Considerations 8. Deployment Considerations
Even if the Internet access provider for consumers is different from Even if the Internet access provider for consumers is different from
the PLAT provider (another Internet access provider or Internet the PLAT provider (e.g. another internet access provider), it can
exchange provider, etc.), it can implement traffic engineering implement traffic engineering independently from the PLAT provider.
independently from the PLAT provider. Detailed reasons are below: Detailed reasons are below:
1. The Internet access provider for consumers can figure out IPv4 1. The Internet access provider for consumers can figure out IPv4
source address and IPv4 destination address from translated IPv6 destination address from translated IPv6 packet header, so it can
packet header, so it can implement traffic engineering based on implement traffic engineering based on IPv4 destination address
IPv4 source address and IPv4 destination address (e.g. traffic (e.g. traffic monitoring for each IPv4 destination address,
monitoring for each IPv4 destination address, packet filtering packet filtering for each IPv4 destination address, etc.). The
for each IPv4 destination address, etc.). The tunneling methods tunneling methods do not have such a advantage, without any deep
do not have such a advantage, without any deep packet inspection packet inspection for processing the inner IPv4 packet of the
for processing the inner IPv4 packet of the tunnel packet. tunnel packet.
2. If the Internet access provider for consumers can assign IPv6 2. If the Internet access provider for consumers can assign IPv6
prefix greater than /64 for each subscriber, this 464XLAT prefix greater than /64 for each subscriber, this 464XLAT
architecture can separate IPv6 prefix for native IPv6 packets and architecture can separate IPv6 prefix for native IPv6 packets and
XLAT prefix for IPv4/IPv6 translation packets. Accordingly, it XLAT prefix for IPv4/IPv6 translation packets. Accordingly, it
can identify the type of packets ("native IPv6 packets" and can identify the type of packets ("native IPv6 packets" and
"IPv4/IPv6 translation packets"), and implement traffic "IPv4/IPv6 translation packets"), and implement traffic
engineering based on IPv6 prefix. engineering based on IPv6 prefix.
This 464XLAT architecture has two capabilities. One is a IPv4 -> This 464XLAT architecture has two capabilities. One is a IPv4 ->
IPv6 -> IPv4 translation for sharing global IPv4 addresses, another IPv6 -> IPv4 translation for sharing global IPv4 addresses, another,
is a IPv4 -> IPv6 translation for reaching IPv6-only servers from if combined with BIH [RFC6535], is a IPv4 -> IPv6 translation for
IPv4-only clients that can not support IPv6. IPv4-only clients must reaching IPv6-only servers from IPv4-only clients that can not
be support through the long period of global transition to IPv6. support IPv6. IPv4-only clients must be support through the long
period of global transition to IPv6.
9. Security Considerations 9. Security Considerations
To implement a PLAT, see security considerations presented in Section To implement a PLAT, see security considerations presented in Section
5 of [RFC6146]. 5 of [RFC6146].
To implement a CLAT, see security considerations presented in Section To implement a CLAT, see security considerations presented in Section
7 of [RFC6145]. The CLAT MAY comply with [RFC6092]. 7 of [RFC6145]. The CLAT MAY comply with [RFC6092].
10. IANA Considerations 10. IANA Considerations
This document has no actions for IANA. IANA is requested to reserve a Modified EUI-64 identifier for 464XLAT
according to section 2.2.2 of [RFC5342]. Its suggested value is 02-
00-5E-00-00-00-00-00 to 02-00-5E-0F-FF-FF-FF-FF or 02-00-5E-10-00-00-
00-00 to 02-00-5E-EF-FF-FF-FF-FF, depending on whether it should be
taken in reserved or available values.
11. Acknowledgements 11. 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, Remi Despres, Tatsuya Asati, Washam Fan, Behcet Sarikaya, Jan Zorz, Tatsuya Oishi, Lorenzo
Oishi, Lorenzo Colitti, Erik Kline, Ole Troan, Maoke Chen, and Gang Colitti, Erik Kline, Ole Troan, Maoke Chen, and Gang Chen for their
Chen for their helpful comments. We also would like to thank Fred helpful comments. Special acknowledgments go to Remi Despres for his
Baker and Joel Jaeggli for their support. plentiful supports and suggestions, especially about using NAT44 with
IANA's EUI-64 ID. We also would like to thank Fred Baker and Joel
Jaeggli for their support.
12. References 12. References
12.1. Normative References 12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[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,
skipping to change at page 14, line 4 skipping to change at page 15, line 8
[I-D.hazeyama-widecamp-ipv6-only-experience] [I-D.hazeyama-widecamp-ipv6-only-experience]
Hazeyama, H., Hiromi, R., Ishihara, T., and O. Nakamura, Hazeyama, H., Hiromi, R., Ishihara, T., and O. Nakamura,
"Experiences from IPv6-Only Networks with Transition "Experiences from IPv6-Only Networks with Transition
Technologies in the WIDE Camp Spring 2012", Technologies in the WIDE Camp Spring 2012",
draft-hazeyama-widecamp-ipv6-only-experience-01 (work in draft-hazeyama-widecamp-ipv6-only-experience-01 (work in
progress), March 2012. progress), March 2012.
[I-D.ietf-behave-nat64-discovery-heuristic] [I-D.ietf-behave-nat64-discovery-heuristic]
Savolainen, T., Korhonen, J., and D. Wing, "Discovery of Savolainen, T., Korhonen, J., and D. Wing, "Discovery of
IPv6 Prefix Used for IPv6 Address Synthesis", IPv6 Prefix Used for IPv6 Address Synthesis",
draft-ietf-behave-nat64-discovery-heuristic-07 (work in draft-ietf-behave-nat64-discovery-heuristic-09 (work in
progress), March 2012. progress), May 2012.
[I-D.mdt-softwire-mapping-address-and-port]
Bao, C., Troan, O., Matsushima, S., Murakami, T., and X.
Li, "Mapping of Address and Port (MAP)",
draft-mdt-softwire-mapping-address-and-port-03 (work in
progress), January 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.
[RFC3123] Koch, P., "A DNS RR Type for Lists of Address Prefixes [RFC3123] Koch, P., "A DNS RR Type for Lists of Address Prefixes
(APL RR)", RFC 3123, June 2001. (APL RR)", RFC 3123, June 2001.
[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.
[RFC5342] Eastlake, D., "IANA Considerations and IETF Protocol Usage
for IEEE 802 Parameters", BCP 141, RFC 5342,
September 2008.
[RFC5625] Bellis, R., "DNS Proxy Implementation Guidelines", [RFC5625] Bellis, R., "DNS Proxy Implementation Guidelines",
BCP 152, RFC 5625, August 2009. BCP 152, RFC 5625, August 2009.
[RFC6092] Woodyatt, J., "Recommended Simple Security Capabilities in [RFC6092] Woodyatt, J., "Recommended Simple Security Capabilities in
Customer Premises Equipment (CPE) for Providing Customer Premises Equipment (CPE) for Providing
Residential IPv6 Internet Service", RFC 6092, Residential IPv6 Internet Service", RFC 6092,
January 2011. January 2011.
[RFC6147] Bagnulo, M., Sullivan, A., Matthews, P., and I. van [RFC6147] Bagnulo, M., Sullivan, A., Matthews, P., and I. van
Beijnum, "DNS64: DNS Extensions for Network Address Beijnum, "DNS64: DNS Extensions for Network Address
Translation from IPv6 Clients to IPv4 Servers", RFC 6147, Translation from IPv6 Clients to IPv4 Servers", RFC 6147,
April 2011. April 2011.
[RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
Stack Lite Broadband Deployments Following IPv4
Exhaustion", RFC 6333, August 2011.
[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.
[RFC6586] Arkko, J. and A. Keranen, "Experiences from an IPv6-Only [RFC6535] Huang, B., Deng, H., and T. Savolainen, "Dual-Stack Hosts
Network", RFC 6586, April 2012. Using "Bump-in-the-Host" (BIH)", RFC 6535, February 2012.
Appendix A. Examples of IPv4/IPv6 Address Translation
The following are examples of IPv4/IPv6 Address Translation on the
464XLAT architecture.
Example 1. (Case of enabling only stateless XLATE on CLAT)
In the case that IPv6 prefix greater than /64 is assigned to end
users by such as DHCPv6-PD [RFC3633], only the function of Stateless
XLATE should be enabled on CLAT. Because the CLAT can use dedicated
a /64 from the assigned IPv6 prefix for Stateless XLATE.
Host & configuration value
+------------------------------+
| IPv4 server |
| [198.51.100.1] | IP packet header
+------------------------------+ +--------------------------------+
^ | Source IP address |
| | [192.0.2.1] |
| | Destination IP address |
| | [198.51.100.1] |
+------------------------------+ +--------------------------------+
| PLAT | ^
| IPv4 pool address | |
| [192.0.2.1 - 192.0.2.100] | |
| PLAT-side XLATE IPv6 prefix | |
| [2001:db8:1234::/96] | |
+------------------------------+ +--------------------------------+
^ | Source IP address |
| | [2001:db8:aaaa::192.168.1.2] |
| | Destination IP address |
| | [2001:db8:1234::198.51.100.1] |
+------------------------------+ +--------------------------------+
| CLAT | ^
| PLAT-side XLATE IPv6 prefix | |
| [2001:db8:1234::/96] | |
| CLAT-side XLATE IPv6 prefix | |
| [2001:db8:aaaa::/96] | |
+------------------------------+ +--------------------------------+
^ | Source IP address |
| | [192.168.1.2] |
| | Destination IP address |
| | [198.51.100.1] |
+------------------------------+ +--------------------------------+
| IPv4 client |
| [192.168.1.2/24] |
+------------------------------+
Delegated IPv6 prefix for client: 2001:db8:aaaa::/56
Example 1. (Case of enabling only stateless XLATE on CLAT)
Example 2. (Case of enabling NAT44 and stateless XLATE on CLAT)
In the case that IPv6 prefix /64 is assigned to end users, the
function of NAT44 and Stateless XLATE should be enabled on CLAT.
Because the CLAT does not have dedicated IPv6 prefix for translation.
Host & configuration value
+-------------------------------+
| IPv4 server |
| [198.51.100.1] | IP packet header
+-------------------------------+ +-------------------------------+
^ | Source IP address |
| | [192.0.2.1] |
| | Destination IP address |
| | [198.51.100.1] |
+-------------------------------+ +-------------------------------+
| PLAT | ^
| IPv4 pool address | |
| [192.0.2.1 - 192.0.2.100] | |
| PLAT-side XLATE IPv6 prefix | |
| [2001:db8:1234::/96] | |
+-------------------------------+ +-------------------------------+
^ | Source IP address |
| | [2001:db8:aaaa:200:5e10:0:0] |
| | Destination IP address |
| | [2001:db8:1234::198.51.100.1] |
| +-------------------------------+
+-------------------------------+ ^
| CLAT Stateless XLATE function | |
| - - - - - - - - - - - - - - - | |
| PLAT-side XLATE IPv6 prefix | |
| [2001:db8:1234::/96] | |
| CLAT-side XLATE IPv6 prefix | |
| [2001:db8:aaaa::/64] | |
| CLAT-side XLATE IPv6 EUI-64 ID| |
| [02-00-5E-10-00-00-00-00] | |
+ - - - - - - - - - - - - - - - + +-------------------------------+
| ^ | | Source IP address |
| | | | [10.255.255.1] |
| | | | Destination IP address |
| | | | [198.51.100.1] |
+ - - - - - - - - - - - - - - - + +-------------------------------+
| CLAT NAT44 function | ^
| - - - - - - - - - - - - - - - | |
| NAT44 NATed address | |
| [10.255.255.1/32] | |
+-------------------------------+ |
^ +-------------------------------+
| | Source IP address |
| | [192.168.1.2] |
| | Destination IP address |
| | [198.51.100.1] |
+-------------------------------+ +-------------------------------+
| IPv4 client |
| [192.168.1.2/24] |
+-------------------------------+
Delegated IPv6 prefix for client: 2001:db8:aaaa::/64
Example 2. (Case of enabling NAT44 and stateless XLATE on CLAT)
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
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