draft-ietf-v6ops-464xlat-06.txt   draft-ietf-v6ops-464xlat-07.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: February 8, 2013 NEC AccessTechnica, Ltd. Expires: February 21, 2013 NEC AccessTechnica, Ltd.
C. Byrne C. Byrne
T-Mobile USA T-Mobile USA
August 7, 2012 August 20, 2012
464XLAT: Combination of Stateful and Stateless Translation 464XLAT: Combination of Stateful and Stateless Translation
draft-ietf-v6ops-464xlat-06 draft-ietf-v6ops-464xlat-07
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 IPv6-only edge networks without encapsulation. access service to IPv6-only edge networks without encapsulation.
skipping to change at page 1, line 37 skipping to change at page 1, line 38
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Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. BCP Scenario . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. BCP Scenario . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Requirements Language . . . . . . . . . . . . . . . . . . . . 4 3. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
4. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Motivation and Uniqueness of 464XLAT . . . . . . . . . . . . . 4 5. Motivation and Uniqueness of 464XLAT . . . . . . . . . . . . . 4
6. Network Architecture . . . . . . . . . . . . . . . . . . . . . 4 6. Network Architecture . . . . . . . . . . . . . . . . . . . . . 4
6.1. Wireline Network Architecture . . . . . . . . . . . . . . 5 6.1. Wireline Network Architecture . . . . . . . . . . . . . . 5
6.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 5 6.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 6
7. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 6 7. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 7
7.1. Wireline Network Applicability . . . . . . . . . . . . . . 6 7.1. Wireline Network Applicability . . . . . . . . . . . . . . 7
7.2. Wireless 3GPP Network Applicability . . . . . . . . . . . 7 7.2. Wireless 3GPP Network Applicability . . . . . . . . . . . 7
8. Implementation Considerations . . . . . . . . . . . . . . . . 7 8. Implementation Considerations . . . . . . . . . . . . . . . . 7
8.1. IPv6 Address Format . . . . . . . . . . . . . . . . . . . 7 8.1. IPv6 Address Format . . . . . . . . . . . . . . . . . . . 8
8.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 7 8.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 8
8.2.1. Case of enabling only stateless XLATE on CLAT . . . . 7 8.2.1. Case of enabling only stateless XLATE on CLAT . . . . 8
8.2.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 9 8.2.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 10
8.3. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 11 8.3. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 12
8.3.1. Case of enabling only stateless XLATE on CLAT . . . . 11 8.3.1. Case of enabling only stateless XLATE on CLAT . . . . 12
8.3.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 11 8.3.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 12
8.4. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 12 8.4. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 12
8.5. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 12 8.5. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 13
8.6. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 12 8.6. CLAT to CLAT communications . . . . . . . . . . . . . . . 13
8.7. CLAT to CLAT communications . . . . . . . . . . . . . . . 12
9. Deployment Considerations . . . . . . . . . . . . . . . . . . 13 9. Deployment Considerations . . . . . . . . . . . . . . . . . . 13
10. Security Considerations . . . . . . . . . . . . . . . . . . . 13 9.1. Traffic Engineering . . . . . . . . . . . . . . . . . . . 13
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 9.2. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 14
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14 10. Security Considerations . . . . . . . . . . . . . . . . . . . 14
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
13.1. Normative References . . . . . . . . . . . . . . . . . . . 14 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15
13.2. Informative References . . . . . . . . . . . . . . . . . . 14 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
13.1. Normative References . . . . . . . . . . . . . . . . . . . 15
13.2. Informative References . . . . . . . . . . . . . . . . . . 15
Appendix A. Examples of IPv4/IPv6 Address Translation . . . . . . 16 Appendix A. Examples of IPv4/IPv6 Address Translation . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction 1. Introduction
The IANA unallocated IPv4 address pool was exhausted on February 3, With the exhaustion of the unallocated IPv4 address pools, it will be
2011. Each RIR's unallocated IPv4 address pool will exhaust in the difficult for many networks to assign IPv4 addresses to end users.
near future. It will be difficult for many networks to assign IPv4
addresses to end users, despite substantial IP connectivity growth
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 architecture only supports IPv4 in the functionality. The 464XLAT architecture only supports IPv4 in the
client server model, where the server has global IPv4 address. This client server model, where the server has a global IPv4 address.
means it is not fit for IPv4 peer-to-peer communication or inbound This means it is not fit for IPv4 peer-to-peer communication or
IPv4 connections. 464XLAT builds on IPv6 transport and includes full inbound IPv4 connections. 464XLAT builds on IPv6 transport and
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, which will be
translated on the CLAT to IPv6 and back to IPv4 on the PLAT. 464XLAT translated on the customer side translator(CLAT) to IPv6 and back to
networks may use DNS64 [RFC6147] to enable single stateful IPv4 on the provider side translator(PLAT). 464XLAT networks may use
translation [RFC6146] instead of 464XLAT double translation where DNS64 [RFC6147] to enable single stateful translation [RFC6146]
possible. The 464XLAT architecture encourages IPv6 transition by instead of 464XLAT double translation where possible. The 464XLAT
making IPv4 services reachable across IPv6-only networks and architecture encourages the IPv6 transition by making IPv4 services
providing IPv6 and IPv4 connectivity to single-stack IPv4 or IPv6 reachable across IPv6-only networks and providing IPv6 and IPv4
servers and peers. connectivity to single-stack IPv4 or IPv6 servers and peers.
By combining 464XLAT with BIH [RFC6535], it is also possible to By combining 464XLAT with BIH [RFC6535], it is also possible to
provide single IPv4 to IPv6 translation service, which will be needed provide single IPv4 to IPv6 translation service, which will be needed
in the future case of IPv6-only servers and peers to be reached from in the future case of IPv6-only servers and peers to be reached from
legacy IPv4-only hosts across IPv6-only networks. IPv4-only hosts across IPv6-only networks.
2. BCP Scenario 2. BCP Scenario
This BCP only applies when the following two criteria are present: This BCP only applies when the following two criteria are present:
1. There is an IPv6-only access network that uses stateful 1. There is an IPv6-only network that uses stateful translation
translation [RFC6146] [RFC6146] as the only mechanism for providing IPv4 access.
2. There are IPv4-only applications or hosts that must communicate 2. There are IPv4-only applications or hosts that must communicate
across the IPv6-only access network to reach the IPv4 Internet across the IPv6-only network to reach the IPv4 Internet.
3. Requirements Language 3. 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].
4. Terminology 4. 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 addresses to global
IPv4 packets, 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
packets to global IPv6 packets, 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. CLAT SHOULD perform router function to mobile phone. The 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 the case where the translation even if it is an end-node. In the case where the
access network does not allow for a dedicated IPv6 prefix for access network does not allow for a dedicated IPv6 prefix for
translation, a NAT44 SHOULD be used between the router translation, a NAT44 SHOULD be used between the router
function and the stateless translator function. The CLAT as function and the stateless translator function. The CLAT as
a common home router or 3G router is expected to perform a common home router or wireless 3GPP router is expected to
gateway functions such as DHCP server and DNS proxy for local perform gateway functions such as DHCP server and DNS proxy
clients. The CLAT does not comply with the sentence "Both for local clients. The CLAT does not comply with the
IPv4-translatable IPv6 addresses and IPv4-converted IPv6 sentence "Both IPv4-translatable IPv6 addresses and IPv4-
addresses SHOULD use the same prefix." that is described on converted IPv6 addresses SHOULD use the same prefix." that is
Section 3.3 in [RFC6052] due to using different IPv6 prefixes described on Section 3.3 in [RFC6052] due to using different
for CLAT-side and PLAT-side IPv4 addresses. IPv6 prefixes for CLAT-side and PLAT-side IPv4 addresses.
5. Motivation and Uniqueness of 464XLAT 5. Motivation and Uniqueness of 464XLAT
1. Minimal IPv4 resource requirements, maximum IPv4 efficiency 1. Minimal IPv4 resource requirements, maximum IPv4 efficiency
through statistical multiplexing through statistical multiplexing.
2. No new protocols required, quick deployment 2. No new protocols required, quick deployment.
3. IPv6-only networks are simpler and therefore less expensive to 3. IPv6-only networks are simpler and therefore less expensive to
operate operate.
6. Network Architecture 6. Network Architecture
464XLAT architecture is shown in the following figure. Examples of 464XLAT architectures are show in the figures in the
following sections.
Wireline Network Architecture can fit in the situations that there
are the clients behind the CLAT in the same way regardless of the
type of access service, for example FTTH, Cable, or WiFi.
Wireless 3GPP Network Architecture can fit in the situations that
client and node that terminate access network is same host in the
same way.
6.1. Wireline Network Architecture 6.1. Wireline Network Architecture
The private IPv4 host on this diagram can reach global IPv4 hosts via 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 translation on both CLAT and PLAT. On the other hand, the IPv6 host
can reach other IPv6 hosts on the Internet directly without can reach other IPv6 hosts on the Internet directly without
translation. This means that the CPE can not only have the function translation. This means that the CPE/CLAT can not only have the
of CLAT but also the function of IPv6 native router for IPv6 native function of a CLAT but also the function of an IPv6 native router for
traffic. native IPv6 traffic. The v4p host behind the CLAT on this diagram
with the private IPv4 addresses.
---- +------+
| v6 | | v6 |
---- | host |
+--+---+
| |
---- | .---+---. .------. .---+---.
| v6 |-----+ / \ / \ / \
---- | ------ / IPv6 \ ------ / IPv4 \ / IPv6 \
+---| CLAT |---+ Internet +---| PLAT |---+ Internet | | Internet |
------- | ------ \ / ------ \ / \ /
|v4p/v6 |--+ `---------' `----+----' `----+----'
------- | | |
----- | ----- +------+ | .---+---. .------.
| v4p |----+ | v4g | | v6 +---+ +------+ / \ +------+ / \
----- | ----- | host | | | | / IPv6 \ | | / IPv4 \
+------+ +---+ CLAT +---+ Network +---+ PLAT +---+ Internet |
+--------+ | | | \ / | | \ /
| v4p/v6 +-+ +------+ `---------' +------+ `----+----'
| host | | |
+--------+ | +--+---+
+------+ | | v4g |
| v4p +---+ | host |
| host | | +------+
+------+ |
<- 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
6.2. Wireless 3GPP Network Architecture 6.2. Wireless 3GPP Network Architecture
The CLAT function on the UE provides an [RFC1918] address and IPv4 The CLAT function on the User Equipment (UE) provides an [RFC1918]
default route. The applications on the UE can use the private IPv4 address and IPv4 default route. The applications on the UE can use
address for reaching global IPv4 hosts via translation on both CLAT the private IPv4 address for reaching global IPv4 hosts via
and PLAT. On the other hand, reaching IPv6 hosts (including host translation on both CLAT and PLAT. On the other hand, reaching IPv6
presented via DNS64 [RFC6147]) does not require the CLAT function on hosts (including host presented via DNS64 [RFC6147]) does not require
the UE. the CLAT function on the UE.
---- +------+
| v6 | | v6 |
---- | host |
+--+---+
| |
.---+---. .---+---.
/ \ / \
/ 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 |
+----------------------+ ----- +----------------------+ | host |
+------+
<- 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 2: Wireless 3GPP Network Topology Figure 2: Wireless 3GPP Network Topology
7. Applicability 7. Applicability
7.1. Wireline Network Applicability 7.1. Wireline Network Applicability
When an ISP has IPv6 464XLAT, the ISP can provide outgoing IPv4 When an ISP has IPv6 access service and provides 464XLAT, the ISP can
service to end users across an IPv6 access network. The result is provide outgoing IPv4 service to end users across an IPv6 access
that edge network growth is no longer tightly coupled to the network. The result is that edge network growth is no longer tightly
availability of scarce IPv4 addresses. coupled to the availability of scarce IPv4 addresses.
If the IXP or another provider operates the PLAT, the edge ISP is If another ISP operates the PLAT, the edge ISP is only required to
only required to deploy an IPv6 access network. All ISPs do not need deploy an IPv6 access network. All ISPs do not need IPv4 access
IPv4 access networks. They can migrate their access network to a networks. They can migrate their access network to a simple and
simple and highly scalable IPv6-only environment. highly scalable IPv6-only environment.
Incidentally, the effectiveness of 464XLAT was confirmed in the WIDE Incidentally, the effectiveness of 464XLAT was confirmed in the WIDE
camp Spring 2012. The result is described in camp Spring 2012. The result is described in
[I-D.hazeyama-widecamp-ipv6-only-experience]. [I-D.hazeyama-widecamp-ipv6-only-experience].
7.2. Wireless 3GPP Network Applicability 7.2. Wireless 3GPP Network Applicability
The vast majority of mobile networks are compliant to Pre-Release 9 The vast majority of mobile networks are compliant to Pre-Release 9
3GPP standards. In Pre-Release 9 3GPP networks, GSM and UMTS 3GPP standards. In Pre-Release 9 3GPP networks, GSM and UMTS
networks must signal and support both IPv4 and IPv6 Packet Data networks must signal and support both IPv4 and IPv6 Packet Data
Protocol (PDP) attachments to access IPv4 and IPv6 network Protocol (PDP) attachments to access IPv4 and IPv6 network
destinations [RFC6459]. Since there are 2 PDPs required to support 2 destinations [RFC6459]. Since there are two PDPs required to support
address families, this is double the number of PDPs required to two address families, this is double the number of PDPs required to
support the status quo of 1 address family, which is IPv4. support the status quo of one address family, which is IPv4.
464XLAT in combination with stateful translation [RFC6146] and DNS64 For the IPv4 literal or IPv4 socket applications that require IPv4
[RFC6147] allows 85% of the Android applications to continue to work connectivity, the CLAT function on the UE provides a private IPv4
with single translation or native IPv6 access. For the remaining 15% address and IPv4 default route on the host for the applications to
of applications that require IPv4 connectivity, the CLAT function on reference and bind to. Connections sourced from the IPv4 interface
the UE provides a private IPv4 address and IPv4 default-route on the are immediately routed to the CLAT function and passed to the IPv6-
host for the applications to reference and bind to. Connections only mobile network, destined for the PLAT. In summary, the UE has
sourced from the IPv4 interface are immediately routed to the CLAT the CLAT function that does a stateless translation [RFC6145], but
function and passed to the IPv6-only mobile network, destine to the only when required. The mobile network has a PLAT that does stateful
PLAT. In summary, the UE has the CLAT function that does a stateless translation [RFC6146].
translation [RFC6145], but only when required. The mobile network
has a PLAT 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 network based deep packet
inspection solutions like 3GPP standardized Policy and Charging inspection solutions like 3GPP standardized Policy and Charging
Control (PCC) [TS.23203]. Control (PCC) [TS.23203].
8. Implementation Considerations 8. Implementation Considerations
8.1. IPv6 Address Format 8.1. IPv6 Address Format
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].
8.2. IPv4/IPv6 Address Translation Chart 8.2. IPv4/IPv6 Address Translation Chart
8.2.1. Case of enabling only stateless XLATE on CLAT 8.2.1. Case of enabling only stateless XLATE on CLAT
This case should be used when a prefix delegation mechanism such as This case should be used when a prefix delegation mechanism such as
DHCPv6-PD [RFC3633] is available to assign a dedicated translation DHCPv6-PD [RFC3633] is available to assign a dedicated translation
prefix to the CLAT. prefix to the CLAT.
Source IPv4 address Destination IPv4 address
+----------------------------+ +----------------------------+
| Global IPv4 address | | Global IPv4 address |
| assigned to IPv4 pool@PLAT | | assigned to IPv4 server |
+--------+ +----------------------------+ +--------+ +----------------------------+
| IPv4 | Destination IPv4 address | IPv4 | Source IPv4 address
| server | +----------------------------+ | server | +----------------------------+
+--------+ | Global IPv4 address | +--------+ | Global IPv4 address |
^ | assigned to IPv4 server | ^ | assigned to IPv4 PLAT pool |
| +----------------------------+ | +----------------------------+
+--------+ +--------+
| PLAT | Stateful XLATE(IPv4:IPv6=1:n) | PLAT | Stateful XLATE(IPv4:IPv6=1:n)
+--------+ +--------+
^ ^
| |
Source IPv6 address (IPv6 cloud) (IPv6 cloud)
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 |
+--------------------------------------------------------------+ +--------------------------------------------------------------+
Destination 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 RFC6052 |
+--------------------------------------------------------------+ +--------------------------------------------------------------+
(IPv6 cloud) (IPv6 cloud)
^ ^
| |
+--------+ +--------+
| | In the case CLAT has a | | In the case the CLAT has a
| | dedicated IPv6 prefix for | | dedicated IPv6 prefix for
| CLAT | translation, the CLAT can | CLAT | translation, the CLAT can
| | perform with only Stateless | | perform with only Stateless
| | XLATE (IPv4:IPv6=1:1). | | XLATE (IPv4:IPv6=1:1).
+--------+ +--------+
^ Source IPv4 address ^ Destination IPv4 address
| +----------------------------+ | +----------------------------+
+--------+ | Private IPv4 address | +--------+ | Global IPv4 address |
| IPv4 | | assigned to IPv4 client | | IPv4 | | assigned to IPv4 server |
| client | +----------------------------+ | client | +----------------------------+
+--------+ Destination IPv4 address +--------+ Source IPv4 address
+----------------------------+ +----------------------------+
| Global IPv4 address | | Private IPv4 address |
| assigned to IPv4 server | | assigned to IPv4 client |
+----------------------------+ +----------------------------+
Case of enabling only stateless XLATE on CLAT Case of enabling only stateless XLATE on CLAT
8.2.2. Case of enabling NAT44 and stateless XLATE on CLAT 8.2.2. Case of enabling NAT44 and stateless XLATE on CLAT
This case should be used when a prefix delegation mechanism is not This case should be used when a prefix delegation mechanism is not
available to assign a dedicated translation prefix to the CLAT. In available to assign a dedicated translation prefix to the CLAT. In
this case, NAT44 SHOULD be used so that all IPv4 source addresses are this case, NAT44 SHOULD be used so that all IPv4 source addresses are
mapped to a single IPv6 address. mapped to a single IPv6 address.
Source IPv4 address Destination IPv4 address
+----------------------------+ +----------------------------+
| Global IPv4 address | | Global IPv4 address |
| assigned to IPv4 pool@PLAT | | assigned to IPv4 server |
+--------+ +----------------------------+ +--------+ +----------------------------+
| IPv4 | Destination IPv4 address | IPv4 | Source IPv4 address
| server | +----------------------------+ | server | +----------------------------+
+--------+ | Global IPv4 address | +--------+ | Global IPv4 address |
^ | assigned to IPv4 server | ^ | assigned to IPv4 PLAT pool |
| +----------------------------+ | +----------------------------+
+--------+ +--------+
| PLAT | Stateful XLATE(IPv4:IPv6=1:n) | PLAT | Stateful XLATE(IPv4:IPv6=1:n)
+--------+ +--------+
^ ^
| |
Source IPv6 address (IPv6 cloud) (IPv6 cloud)
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 |
+--------------------------------------------------------------+ +--------------------------------------------------------------+
Destination 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 RFC6052 |
+--------------------------------------------------------------+ +--------------------------------------------------------------+
(IPv6 cloud) (IPv6 cloud)
^ ^
| |
+--------+ +--------+
| | In the case CLAT does not have | | In the case the CLAT does not
| | a dedicated IPv6 prefix for | | have a dedicated IPv6 prefix
| CLAT | translation, the CLAT can | CLAT | for translation, the CLAT can
| | perform with NAT44 and | | perform with NAT44 and
| | Stateless XLATE | | Stateless XLATE
| | (IPv4:IPv6=1:1). | | (IPv4:IPv6=1:1).
+--------+ +--------+
^ Source IPv4 address ^ Destination IPv4 address
| +----------------------------+ | +----------------------------+
+--------+ | Private IPv4 address | +--------+ | Global IPv4 address |
| IPv4 | | assigned to IPv4 client | | IPv4 | | assigned to IPv4 server |
| client | +----------------------------+ | client | +----------------------------+
+--------+ Destination IPv4 address +--------+ Source IPv4 address
+----------------------------+ +----------------------------+
| Global IPv4 address | | Private IPv4 address |
| assigned to IPv4 server | | assigned to IPv4 client |
+----------------------------+ +----------------------------+
Case of enabling NAT44 and stateless XLATE on CLAT Case of enabling NAT44 and stateless XLATE on CLAT
8.3. IPv6 Prefix Handling 8.3. IPv6 Prefix Handling
8.3.1. Case of enabling only stateless XLATE on CLAT 8.3.1. Case of enabling only stateless XLATE on CLAT
From the delegated DHCPv6 [RFC3633] prefix, a /64 is dedicated to From the delegated DHCPv6 [RFC3633] prefix, a /64 is dedicated to
source and receive IPv6 packets associated with the stateless source and receive IPv6 packets associated with the stateless
translation [RFC6145]. translation [RFC6145].
The CLAT MAY discover the Pref64::/n of the PLAT via some method such The CLAT MAY discover the Pref64::/n of the PLAT via some method such
as DHCPv6 option, TR-069, DNS APL RR [RFC3123] or as DHCPv6 option, TR-069, DNS APL RR [RFC3123] or
[I-D.ietf-behave-nat64-discovery-heuristic]. [I-D.ietf-behave-nat64-discovery-heuristic].
8.3.2. Case of enabling NAT44 and stateless XLATE on CLAT 8.3.2. Case of enabling NAT44 and stateless XLATE on CLAT
In the case that DHCPv6-PD [RFC3633] is not available, the CLAT does In the case that DHCPv6-PD [RFC3633] is not available, the CLAT may
not have dedicated IPv6 prefix for translation. If the CLAT does not not have a dedicated IPv6 prefix for translation. If the CLAT does
have a dedicated IPv6 prefix for translation, the CLAT can perform not have a dedicated IPv6 prefix for translation, the CLAT can
with NAT44 and stateless translation [RFC6145]. perform NAT44 and stateless translation [RFC6145].
Incoming source IPv4 packets from the LAN of [RFC1918] addresses are IPv4 packets from the LAN are NAT44 to the private IPv4 host address
NAT44 to the CLAT IPv4 host address. Then, the CLAT will do a of the CLAT that is not included in LAN segment of CLAT. Then, the
stateless translation [RFC6145] so that the IPv4 packets from the CLAT will do a stateless translation [RFC6145] so that the IPv4
CLAT IPv4 host address are translated to the CLAT WAN IPv6 address as packets from the CLAT IPv4 host address are translated to the CLAT
described in [RFC6052]. WAN IPv6 address as described in [RFC6145].
Its subnet prefix is made of the delegated prefix, completed if If the CLAT cannot perform ND Proxy [RFC4389] due to the restriction
needed to a /64 by a subnet ID = 0. Its interface ID is the 464XLAT of the implementation, the CLAT may use a dedicated IANA assigned
interface ID (Section 10). EUI-64 ID for creating a translated IPv6 address to be used in
stateless translation [RFC6145]. This will allow the CLAT to avoid
possible IPv6 address duplication issues between an IPv6 address for
stateless translation [RFC6145] in the CLAT and an IPv6 address
assigned to native IPv6 nodes behind the CLAT. This document
describes an example for this case in Example 2. of the Appendix A.
The CLAT MAY discover the Pref64::/n of the PLAT via some method such The CLAT MAY discover the Pref64::/n of the PLAT via some method such
as TR-069, DNS APL RR [RFC3123] or as TR-069, DNS APL RR [RFC3123] or
[I-D.ietf-behave-nat64-discovery-heuristic]. [I-D.ietf-behave-nat64-discovery-heuristic].
8.4. Traffic Treatment Scenarios 8.4. DNS Proxy Implementation
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
is undesirable since it requires both stateful and stateless
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
IPv6 LAN clients. Using the CLAT enabled home router or UE as a DNS
proxy is a normal consumer gateway function and simplifies the
traffic flow so 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 choice and bypass the proxy.
8.5. CLAT in a Gateway
The CLAT is a stateless translation feature which can be implemented
in a common home router or mobile phone that has a tethering feature.
The router with CLAT function SHOULD provide common router services
such as DHCP of [RFC1918] addresses, DHCPv6, and DNS service.
8.6. CLAT to CLAT communications
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
a hub and spoke architecture focused on enabling IPv4-only services
over IPv6-only networks.
9. Deployment Considerations
9.1. Traffic Engineering
Even if the ISP for end users is different from the PLAT provider
(e.g. another ISP), it can implement traffic engineering
independently from the PLAT provider. Detailed reasons are below:
1. The ISP for end users can figure out IPv4 destination address
from translated IPv6 packet header, so it can implement traffic
engineering based on IPv4 destination address (e.g. traffic
monitoring for each IPv4 destination address, packet filtering
for each IPv4 destination address, etc.). The tunneling methods
do not have such an advantage, without any deep 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
/64 to each subscriber, this 464XLAT architecture can separate
IPv6 prefix for native IPv6 packets and the XLAT prefixes for
IPv4/IPv6 translation packets. Accordingly, it can identify the
type of packets ("native IPv6 packets" and "IPv4/IPv6 translation
packets"), and implement traffic engineering based on the IPv6
prefix.
9.2. Traffic Treatment Scenarios
This 464XLAT architecture has capabilities. One is a IPv4 -> IPv6 ->
IPv4 translation for sharing global IPv4 addresses as a basic
function, another, if combined with BIH [RFC6535], is a IPv4 -> IPv6
translation for reaching IPv6-only servers from IPv4-only clients
that can not support IPv6. IPv4-only clients must be support through
the long period of global transition to IPv6.
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| 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 | BIH | 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.
8.5. DNS Proxy Implementation
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
undesirable since it requires both stateful and stateless 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 IPv6
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
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
choice and bypass the proxy.
8.6. CLAT in a Gateway
The CLAT is a stateless translation feature which can be implemented
in a common home router or mobile phone that has a mobile router
feature. The router with CLAT function SHOULD provide common router
services such as DHCP of [RFC1918] addresses, DHCPv6, and DNS
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
DNS proxy function to avoid double translation of DNS request.
8.7. CLAT to CLAT communications
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
a hub and spoke architecture focused on enabling IPv4-only services
over IPv6-only access networks.
9. Deployment Considerations
Even if the Internet access provider for consumers is different from
the PLAT provider (e.g. another internet access provider), it can
implement traffic engineering independently from the PLAT provider.
Detailed reasons are below:
1. The Internet access provider for consumers can figure out IPv4
destination address from translated IPv6 packet header, so it can
implement traffic engineering based on IPv4 destination address
(e.g. traffic monitoring for each IPv4 destination address,
packet filtering for each IPv4 destination address, etc.). The
tunneling methods do not have such a advantage, without any deep
packet inspection for processing the inner IPv4 packet of the
tunnel packet.
2. If the Internet access provider for consumers can assign IPv6
prefix greater than /64 for each subscriber, this 464XLAT
architecture can separate IPv6 prefix for native IPv6 packets and
XLAT prefix for IPv4/IPv6 translation packets. Accordingly, it
can identify the type of packets ("native IPv6 packets" and
"IPv4/IPv6 translation packets"), and implement traffic
engineering based on IPv6 prefix.
This 464XLAT architecture has two capabilities. One is a IPv4 ->
IPv6 -> IPv4 translation for sharing global IPv4 addresses, another,
if combined with BIH [RFC6535], is a IPv4 -> IPv6 translation for
reaching IPv6-only servers from IPv4-only clients that can not
support IPv6. IPv4-only clients must be support through the long
period of global transition to IPv6.
10. Security Considerations 10. 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].
11. IANA Considerations 11. IANA Considerations
skipping to change at page 14, line 14 skipping to change at page 15, line 10
according to section 2.2.2 of [RFC5342]. Its suggested value is 02- 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- 00-5E-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 00-00 to 02-00-5E-EF-FF-FF-FF-FF, depending on whether it should be
taken in reserved or available values. taken in reserved or available values.
12. Acknowledgements 12. 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, and Colitti, Erik Kline, Ole Troan, Maoke Chen, Gang Chen, Tom Petch,
Jouni Korhonen for their helpful comments. Special acknowledgments Jouni Korhonen, and Bjoern A. Zeeb for their helpful comments.
go to Remi Despres for his plentiful supports and suggestions, Special acknowledgments go to Remi Despres for his plentiful supports
especially about using NAT44 with IANA's EUI-64 ID. We also would and suggestions, especially about using NAT44 with IANA's EUI-64 ID.
like to thank Fred Baker and Joel Jaeggli for their support. We also would like to thank Fred Baker and Joel Jaeggli for their
support.
13. References 13. References
13.1. Normative References 13.1. 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 15, line 22 skipping to change at page 16, line 16
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.
[RFC4389] Thaler, D., Talwar, M., and C. Patel, "Neighbor Discovery
Proxies (ND Proxy)", RFC 4389, April 2006.
[RFC5342] Eastlake, D., "IANA Considerations and IETF Protocol Usage [RFC5342] Eastlake, D., "IANA Considerations and IETF Protocol Usage
for IEEE 802 Parameters", BCP 141, RFC 5342, for IEEE 802 Parameters", BCP 141, RFC 5342,
September 2008. 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,
skipping to change at page 16, line 12 skipping to change at page 17, line 7
[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 are examples of IPv4/IPv6 Address Translation on the The following are examples of IPv4/IPv6 Address Translation on the
464XLAT architecture. 464XLAT architecture.
Example 1. (Case of enabling only stateless XLATE on CLAT) Example 1. (Case of enabling only stateless XLATE on CLAT)
In the case that IPv6 prefix greater than /64 is assigned to end In the case that an IPv6 prefix greater than /64 is assigned to an
users by such as DHCPv6-PD [RFC3633], only the function of Stateless end user by such as DHCPv6-PD [RFC3633], only the Stateless XLATE
XLATE should be enabled on CLAT. Because the CLAT can use dedicated functionality should be enabled on the CLAT as the CLAT can use a
a /64 from the assigned IPv6 prefix for Stateless XLATE. dedicated /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
+------------------------------+ +--------------------------------+ +------------------------------+ +--------------------------------+
^ | Source IP address | ^ | Destination IP address |
| | [192.0.2.1] |
| | Destination IP address |
| | [198.51.100.1] | | | [198.51.100.1] |
| | Source IP address |
| | [192.0.2.1] |
+------------------------------+ +--------------------------------+ +------------------------------+ +--------------------------------+
| PLAT | ^ | PLAT | ^
| IPv4 pool address | | | IPv4 pool address | |
| [192.0.2.1 - 192.0.2.100] | | | [192.0.2.1 - 192.0.2.100] | |
| PLAT-side XLATE IPv6 prefix | | | PLAT-side XLATE IPv6 prefix | |
| [2001:db8:1234::/96] | | | [2001:db8:1234::/96] | |
+------------------------------+ +--------------------------------+ +------------------------------+ +--------------------------------+
^ | Source IP address | ^ | Destination IP address |
| | [2001:db8:aaaa::192.168.1.2] |
| | Destination IP address |
| | [2001:db8:1234::198.51.100.1] | | | [2001:db8:1234::198.51.100.1] |
| | Source IP address |
| | [2001:db8:aaaa::192.168.1.2] |
+------------------------------+ +--------------------------------+ +------------------------------+ +--------------------------------+
| CLAT | ^ | CLAT | ^
| PLAT-side XLATE IPv6 prefix | | | PLAT-side XLATE IPv6 prefix | |
| [2001:db8:1234::/96] | | | [2001:db8:1234::/96] | |
| CLAT-side XLATE IPv6 prefix | | | CLAT-side XLATE IPv6 prefix | |
| [2001:db8:aaaa::/96] | | | [2001:db8:aaaa::/96] | |
+------------------------------+ +--------------------------------+ +------------------------------+ +--------------------------------+
^ | Source IP address | ^ | Destination IP address |
| | [192.168.1.2] |
| | Destination IP address |
| | [198.51.100.1] | | | [198.51.100.1] |
| | Source IP address |
| | [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
Example 2. (Case of enabling NAT44 and 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 In the case that IPv6 prefix /64 is assigned to end users, the
function of NAT44 and Stateless XLATE should be enabled on CLAT. function of NAT44 and Stateless XLATE should be enabled on CLAT.
Because the CLAT does not have dedicated IPv6 prefix for translation. Because the CLAT does not have dedicated IPv6 prefix for translation.
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 18, line 10 skipping to change at page 18, line 15
In the case that IPv6 prefix /64 is assigned to end users, the In the case that IPv6 prefix /64 is assigned to end users, the
function of NAT44 and Stateless XLATE should be enabled on CLAT. function of NAT44 and Stateless XLATE should be enabled on CLAT.
Because the CLAT does not have dedicated IPv6 prefix for translation. Because the CLAT does not have dedicated IPv6 prefix for translation.
Host & configuration value Host & configuration value
+-------------------------------+ +-------------------------------+
| IPv4 server | | IPv4 server |
| [198.51.100.1] | IP packet header | [198.51.100.1] | IP packet header
+-------------------------------+ +-------------------------------+ +-------------------------------+ +-------------------------------+
^ | Source IP address | ^ | Destination IP address |
| | [192.0.2.1] |
| | Destination IP address |
| | [198.51.100.1] | | | [198.51.100.1] |
| | Source IP address |
| | [192.0.2.1] |
+-------------------------------+ +-------------------------------+ +-------------------------------+ +-------------------------------+
| PLAT | ^ | PLAT | ^
| IPv4 pool address | | | IPv4 pool address | |
| [192.0.2.1 - 192.0.2.100] | | | [192.0.2.1 - 192.0.2.100] | |
| PLAT-side XLATE IPv6 prefix | | | PLAT-side XLATE IPv6 prefix | |
| [2001:db8:1234::/96] | | | [2001:db8:1234::/96] | |
+-------------------------------+ +-------------------------------+ +-------------------------------+ +-------------------------------+
^ | Source IP address | ^ | Destination IP address |
| | [2001:db8:aaaa:200:5e10:0:0] |
| | Destination IP address |
| | [2001:db8:1234::198.51.100.1] | | | [2001:db8:1234::198.51.100.1] |
| | Source IP address |
| | [2001:db8:aaaa:0:200:5e10::] |
+-------------------------------+ +-------------------------------+ +-------------------------------+ +-------------------------------+
| CLAT Stateless XLATE function | ^ | CLAT Stateless XLATE function | ^
| - - - - - - - - - - - - - - - | | | - - - - - - - - - - - - - - - | |
| PLAT-side XLATE IPv6 prefix | | | PLAT-side XLATE IPv6 prefix | |
| [2001:db8:1234::/96] | | | [2001:db8:1234::/96] | |
| CLAT-side XLATE IPv6 prefix | | | CLAT-side XLATE IPv6 prefix | |
| [2001:db8:aaaa::/64] | | | [2001:db8:aaaa::/64] | |
| CLAT-side XLATE IPv6 EUI-64 ID| | | CLAT-side XLATE IPv6 EUI-64 ID| |
| [02-00-5E-10-00-00-00-00] | | | [02-00-5E-10-00-00-00-00] | |
+ - - - - - - - - - - - - - - - + +-------------------------------+ + - - - - - - - - - - - - - - - + +-------------------------------+
| ^ | | Source IP address | | ^ | | Destination IP address |
| | | | [10.255.255.1] |
| | | | Destination IP address |
| | | | [198.51.100.1] | | | | | [198.51.100.1] |
| | | | Source IP address |
| | | | [10.255.255.1] |
+ - - - - - - - - - - - - - - - + +-------------------------------+ + - - - - - - - - - - - - - - - + +-------------------------------+
| CLAT NAT44 function | ^ | CLAT NAT44 function | ^
| - - - - - - - - - - - - - - - | | | - - - - - - - - - - - - - - - | |
| NAT44 NATed address | | | NAT44 NATed address | |
| [10.255.255.1/32] | | | [10.255.255.1/32] | |
+-------------------------------+ +-------------------------------+ +-------------------------------+ +-------------------------------+
^ | Source IP address | ^ | Destination IP address |
| | [192.168.1.2] |
| | Destination IP address |
| | [198.51.100.1] | | | [198.51.100.1] |
| | Source IP address |
| | [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::/64 Delegated IPv6 prefix for client: 2001:db8:aaaa::/64
Authors' Addresses Authors' Addresses
Masataka Mawatari Masataka Mawatari
Japan Internet Exchange Co.,Ltd. Japan Internet Exchange Co.,Ltd.
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