draft-ietf-v6ops-464xlat-07.txt   draft-ietf-v6ops-464xlat-08.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 21, 2013 NEC AccessTechnica, Ltd. Expires: March 22, 2013 NEC AccessTechnica, Ltd.
C. Byrne C. Byrne
T-Mobile USA T-Mobile USA
August 20, 2012 September 18, 2012
464XLAT: Combination of Stateful and Stateless Translation 464XLAT: Combination of Stateful and Stateless Translation
draft-ietf-v6ops-464xlat-07 draft-ietf-v6ops-464xlat-08
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 38 skipping to change at page 1, line 38
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on February 21, 2013. This Internet-Draft will expire on March 22, 2013.
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
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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publication of this document. Please review these documents publication of this document. Please review these documents
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. BCP Scenario . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. BCP Scenario . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 3. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
4. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
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 . . . . . . . . . . . . . . 4
6.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 6 6.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 5
7. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 7 7. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Wireline Network Applicability . . . . . . . . . . . . . . 7 7.1. Wireline Network Applicability . . . . . . . . . . . . . . 6
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 . . . . . . . . . . . . . . . . . . . 8 8.1. IPv6 Address Format . . . . . . . . . . . . . . . . . . . 7
8.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 8 8.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 7
8.2.1. Case of enabling only stateless XLATE on CLAT . . . . 8 8.3. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 9
8.2.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 10 8.4. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 9
8.3. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 12 8.5. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 9
8.3.1. Case of enabling only stateless XLATE on CLAT . . . . 12 8.6. CLAT to CLAT communications . . . . . . . . . . . . . . . 9
8.3.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 12 9. Deployment Considerations . . . . . . . . . . . . . . . . . . 9
8.4. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 12 9.1. Traffic Engineering . . . . . . . . . . . . . . . . . . . 10
8.5. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 13 9.2. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 10
8.6. CLAT to CLAT communications . . . . . . . . . . . . . . . 13 10. Security Considerations . . . . . . . . . . . . . . . . . . . 11
9. Deployment Considerations . . . . . . . . . . . . . . . . . . 13 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
9.1. Traffic Engineering . . . . . . . . . . . . . . . . . . . 13 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11
9.2. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 14 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
10. Security Considerations . . . . . . . . . . . . . . . . . . . 14 13.1. Normative References . . . . . . . . . . . . . . . . . . . 11
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 13.2. Informative References . . . . . . . . . . . . . . . . . . 12
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15 Appendix A. Examples of IPv4/IPv6 Address Translation . . . . . . 12
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
13.1. Normative References . . . . . . . . . . . . . . . . . . . 15
13.2. Informative References . . . . . . . . . . . . . . . . . . 15
Appendix A. Examples of IPv4/IPv6 Address Translation . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction 1. Introduction
With the exhaustion of the unallocated IPv4 address pools, it will be With the exhaustion of the unallocated IPv4 address pools, it will be
difficult for many networks to assign IPv4 addresses to end users. difficult for many networks to assign IPv4 addresses to end users.
This document describes an IPv4 over IPv6 solution as one of the This document describes an IPv4 over IPv6 solution as one of the
techniques for IPv4 service extension and encouragement of IPv6 techniques for IPv4 service extension and encouragement of IPv6
deployment. 464XLAT is not a one-for-one replacement of full IPv4 deployment. 464XLAT is not a one-for-one replacement of full IPv4
functionality. The 464XLAT architecture only supports IPv4 in the functionality. The 464XLAT architecture only supports IPv4 in the
skipping to change at page 3, line 31 skipping to change at page 3, line 31
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 customer side translator(CLAT) to IPv6 and back to translated on the customer side translator(CLAT) to IPv6 and back to
IPv4 on the provider side translator(PLAT). 464XLAT networks may use IPv4 on the provider side translator(PLAT). 464XLAT networks may use
DNS64 [RFC6147] to enable single stateful translation [RFC6146] DNS64 [RFC6147] to enable single stateful translation [RFC6146]
instead of 464XLAT double translation where possible. The 464XLAT instead of 464XLAT double translation where possible. The 464XLAT
architecture encourages the IPv6 transition by making IPv4 services architecture encourages the IPv6 transition by making IPv4 services
reachable across IPv6-only networks and providing IPv6 and IPv4 reachable across IPv6-only networks and providing IPv6 and IPv4
connectivity to single-stack IPv4 or IPv6 servers and peers. connectivity to single-stack IPv4 or IPv6 servers and peers.
By combining 464XLAT with BIH [RFC6535], it is also possible to
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
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 network that uses stateful translation 1. There is an IPv6-only network that uses stateful translation
[RFC6146] as the only mechanism for providing IPv4 access. [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 network to reach the IPv4 Internet. across the IPv6-only network to reach the IPv4 Internet.
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PLAT: PLAT is Provider side translator(XLAT) that complies with PLAT: PLAT is Provider side translator(XLAT) that complies with
[RFC6146]. It translates N:1 global IPv6 addresses to global [RFC6146]. It translates N:1 global IPv6 addresses to global
IPv4 addresses, and vice versa. IPv4 addresses, and vice versa.
CLAT: CLAT is Customer side translator(XLAT) that complies with CLAT: CLAT is Customer side translator(XLAT) that complies with
[RFC6145]. It algorithmically translates 1:1 private IPv4 [RFC6145]. It algorithmically translates 1:1 private IPv4
addresses to global IPv6 addresses, and vice versa. The CLAT addresses to global IPv6 addresses, and vice versa. The CLAT
function is applicable to a router or an end-node such as a function is applicable to a router or an end-node such as a
mobile phone. The CLAT SHOULD perform 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. The CLAT as a common
access network does not allow for a dedicated IPv6 prefix for home router or wireless 3GPP router is expected to perform
translation, a NAT44 SHOULD be used between the router gateway functions such as DHCP server and DNS proxy for local
function and the stateless translator function. The CLAT as clients. The CLAT does not comply with the sentence "Both
a common home router or wireless 3GPP router is expected to IPv4-translatable IPv6 addresses and IPv4-converted IPv6
perform gateway functions such as DHCP server and DNS proxy addresses SHOULD use the same prefix." that is described on
for local clients. The CLAT does not comply with the Section 3.3 in [RFC6052] due to using different IPv6 prefixes
sentence "Both IPv4-translatable IPv6 addresses and IPv4- for CLAT-side and PLAT-side IPv4 addresses.
converted IPv6 addresses SHOULD use the same prefix." that is
described on Section 3.3 in [RFC6052] due to using different
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
Examples of 464XLAT architectures are show in the figures in the Examples of 464XLAT architectures are shown in the figures in the
following sections. following sections.
Wireline Network Architecture can fit in the situations that there Wireline Network Architecture can fit in the situations where there
are the clients behind the CLAT in the same way regardless of the are clients behind the CLAT in the same way regardless of the type of
type of access service, for example FTTH, Cable, or WiFi. access service, for example FTTH, DOCSIS, or WiFi.
Wireless 3GPP Network Architecture can fit in the situations that Wireless 3GPP Network Architecture fits in the situations where a
client and node that terminate access network is same host in the client terminates the wireless access network and may act as a router
same way. with tethered clients.
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/CLAT can not only have the translation. This means that the CPE/CLAT can not only have the
function of a CLAT but also the function of an IPv6 native router for function of a CLAT but also the function of an IPv6 native router for
native IPv6 traffic. The v4p host behind the CLAT on this diagram native IPv6 traffic. The v4p host behind the CLAT on this diagram
with the private IPv4 addresses. has [RFC1918] addresses.
+------+ +------+
| v6 | | v6 |
| host | | host |
+--+---+ +--+---+
| |
.---+---. .---+---.
/ \ / \
/ IPv6 \ / IPv6 \
| Internet | | Internet |
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v6 : Global IPv6 v6 : Global IPv6
v4p : Private IPv4 v4p : Private IPv4
v4g : Global IPv4 v4g : Global IPv4
Figure 1: Wireline Network Topology Figure 1: Wireline Network Topology
6.2. Wireless 3GPP Network Architecture 6.2. Wireless 3GPP Network Architecture
The CLAT function on the User Equipment (UE) provides an [RFC1918] The CLAT function on the User Equipment (UE) provides an [RFC1918]
address and IPv4 default route. The applications on the UE can use address and IPv4 default route to the local node network stack. The
the private IPv4 address for reaching global IPv4 hosts via applications on the UE can use the private IPv4 address for reaching
translation on both CLAT and PLAT. On the other hand, reaching IPv6 global IPv4 hosts via translation on both the CLAT and the PLAT. On
hosts (including host presented via DNS64 [RFC6147]) does not require the other hand, reaching IPv6 hosts (including host presented via
the CLAT function on the UE. DNS64 [RFC6147]) does not require the CLAT function on the UE.
Presenting a private IPv4 network for tethering via NAT44 and
stateless translation on the UE is also an application of the CLAT.
+------+ +------+
| v6 | | v6 |
| host | | host |
+--+---+ +--+---+
| |
.---+---. .---+---.
/ \ / \
/ IPv6 \ / IPv6 \
| Internet | | Internet |
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When an ISP has IPv6 access service and provides 464XLAT, the ISP can When an ISP has IPv6 access service and provides 464XLAT, the ISP can
provide outgoing IPv4 service to end users across an IPv6 access provide outgoing IPv4 service to end users across an IPv6 access
network. The result is that edge network growth is no longer tightly network. The result is that edge network growth is no longer tightly
coupled to the availability of scarce IPv4 addresses. coupled to the availability of scarce IPv4 addresses.
If another ISP operates the PLAT, the edge ISP is only required to If another ISP operates the PLAT, the edge ISP is only required to
deploy an IPv6 access network. All ISPs do not need IPv4 access deploy an IPv6 access network. All ISPs do not need IPv4 access
networks. They can migrate their access network to a simple and networks. They can migrate their access network to a simple and
highly scalable IPv6-only environment. highly scalable IPv6-only environment.
Incidentally, the effectiveness of 464XLAT was confirmed in the WIDE
camp Spring 2012. The result is described in
[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 At the time of writing, in September 2012, the vast majority of
3GPP standards. In Pre-Release 9 3GPP networks, GSM and UMTS mobile networks are compliant to Pre-Release 9 3GPP standards. In
networks must signal and support both IPv4 and IPv6 Packet Data Pre-Release 9 3GPP networks, GSM and UMTS networks must signal and
Protocol (PDP) attachments to access IPv4 and IPv6 network support both IPv4 and IPv6 Packet Data Protocol (PDP) attachments to
destinations [RFC6459]. Since there are two PDPs required to support access IPv4 and IPv6 network destinations [RFC6459]. Since there are
two address families, this is double the number of PDPs required to two PDPs required to support two address families, this is double the
support the status quo of one address family, which is IPv4. number of PDPs required to support the status quo of one address
family, which is IPv4.
For the IPv4 literal or IPv4 socket applications that require IPv4 For the cases of connecting to an IPv4 literal or IPv4 socket that
connectivity, the CLAT function on the UE provides a private IPv4 require IPv4 connectivity, the CLAT function on the UE provides a
address and IPv4 default route on the host for the applications to private IPv4 address and IPv4 default route on the host for the
reference and bind to. Connections sourced from the IPv4 interface applications to reference and bind to. Connections sourced from the
are immediately routed to the CLAT function and passed to the IPv6- IPv4 interface are immediately routed to the CLAT function and passed
only mobile network, destined for the PLAT. In summary, the UE has to the IPv6-only mobile network, destined for the PLAT. In summary,
the CLAT function that does a stateless translation [RFC6145], but the UE has the CLAT function that does a stateless translation
only when required. The mobile network has a PLAT that does stateful [RFC6145], but only when required by an IPv4-only scenario such as
translation [RFC6146]. IPv4 literals or IPv4-only sockets. 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
The IPv6 address format in 464XLAT is defined in Section 2.2 of The IPv6 address format in 464XLAT is defined in Section 2.2 of
[RFC6052]. [RFC6052].
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 This chart offers a explanation about address translation
architecture using combination of stateful translation at the PLAT
This case should be used when a prefix delegation mechanism such as and stateless translation at the CLAT. The client on this chart is
DHCPv6-PD [RFC3633] is available to assign a dedicated translation delegated IPv6 prefix from a prefix delegation mechanism such as
prefix to the CLAT. DHCPv6-PD [RFC3633], therefore it has a dedicated IPv6 prefix for
translation.
Destination IPv4 address Destination IPv4 address
+----------------------------+ +----------------------------+
| Global IPv4 address | | Global IPv4 address |
| assigned to IPv4 server | | assigned to IPv4 server |
+--------+ +----------------------------+ +--------+ +----------------------------+
| IPv4 | Source IPv4 address | IPv4 | Source IPv4 address
| server | +----------------------------+ | server | +----------------------------+
+--------+ | Global IPv4 address | +--------+ | Global IPv4 address |
^ | assigned to IPv4 PLAT pool | ^ | assigned to IPv4 PLAT pool |
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+--------------------------------------------------------------+ +--------------------------------------------------------------+
Source IPv6 address Source IPv6 address
+--------------------------------------------------------------+ +--------------------------------------------------------------+
| IPv4-Embedded IPv6 address | | IPv4-Embedded IPv6 address |
| defined in Section 2.2 of RFC6052 | | defined in Section 2.2 of RFC6052 |
+--------------------------------------------------------------+ +--------------------------------------------------------------+
(IPv6 cloud) (IPv6 cloud)
^ ^
| |
+--------+ +--------+
| | In the case the CLAT has a | CLAT | Stateless XLATE(IPv4:IPv6=1:1)
| | dedicated IPv6 prefix for
| CLAT | translation, the CLAT can
| | perform with only Stateless
| | XLATE (IPv4:IPv6=1:1).
+--------+ +--------+
^ Destination IPv4 address ^ Destination IPv4 address
| +----------------------------+ | +----------------------------+
+--------+ | Global IPv4 address | +--------+ | Global IPv4 address |
| IPv4 | | assigned to IPv4 server | | IPv4 | | assigned to IPv4 server |
| client | +----------------------------+ | client | +----------------------------+
+--------+ Source IPv4 address +--------+ Source IPv4 address
+----------------------------+ +----------------------------+
| Private IPv4 address | | Private IPv4 address |
| assigned to IPv4 client | | assigned to IPv4 client |
+----------------------------+ +----------------------------+
Case of enabling only stateless XLATE on CLAT Case of enabling only 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
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.
Destination IPv4 address
+----------------------------+
| Global IPv4 address |
| assigned to IPv4 server |
+--------+ +----------------------------+
| IPv4 | Source IPv4 address
| server | +----------------------------+
+--------+ | Global IPv4 address |
^ | assigned to IPv4 PLAT pool |
| +----------------------------+
+--------+
| PLAT | Stateful XLATE(IPv4:IPv6=1:n)
+--------+
^
|
(IPv6 cloud)
Destination IPv6 address
+--------------------------------------------------------------+
| IPv4-Embedded IPv6 address |
| defined in Section 2.2 of RFC6052 |
+--------------------------------------------------------------+
Source IPv6 address
+--------------------------------------------------------------+
| IPv4-Embedded IPv6 address |
| defined in Section 2.2 of RFC6052 |
+--------------------------------------------------------------+
(IPv6 cloud)
^
|
+--------+
| | In the case the CLAT does not
| | have a dedicated IPv6 prefix
| CLAT | for translation, the CLAT can
| | perform with NAT44 and
| | Stateless XLATE
| | (IPv4:IPv6=1:1).
+--------+
^ Destination IPv4 address
| +----------------------------+
+--------+ | Global IPv4 address |
| IPv4 | | assigned to IPv4 server |
| client | +----------------------------+
+--------+ Source IPv4 address
+----------------------------+
| Private IPv4 address |
| assigned to IPv4 client |
+----------------------------+
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 The CLAT SHOULD acquire a dedicated /64 prefix for the purpose of
sending and receiving statelessly translated packets.
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].
8.3.2. Case of enabling NAT44 and stateless XLATE on CLAT
In the case that DHCPv6-PD [RFC3633] is not available, the CLAT may
not have a dedicated IPv6 prefix for translation. If the CLAT does
not have a dedicated IPv6 prefix for translation, the CLAT can
perform NAT44 and stateless translation [RFC6145].
IPv4 packets from the LAN are NAT44 to the private IPv4 host address
of the CLAT that is not included in LAN segment of CLAT. 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 [RFC6145].
If the CLAT cannot perform ND Proxy [RFC4389] due to the restriction The CLAT MAY discover the PLAT-side translation IPv6 prefix used as a
of the implementation, the CLAT may use a dedicated IANA assigned destination of the PLAT via
EUI-64 ID for creating a translated IPv6 address to be used in [I-D.ietf-behave-nat64-discovery-heuristic]. In the future some
stateless translation [RFC6145]. This will allow the CLAT to avoid other mechanisms, such as a new DHCPv6 option, will possibly be
possible IPv6 address duplication issues between an IPv6 address for defined.
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 When a dedicated /64 prefix is not available from DHCPv6-PD
as TR-069, DNS APL RR [RFC3123] or [RFC3633], the CLAT MAY perform NAT44 for all IPv4 LAN packets so
[I-D.ietf-behave-nat64-discovery-heuristic]. that all the LAN originated IPv4 packets appear from a single IPv4
address and are then statelessly translated to one IPv6 address that
is claimed by the CLAT via NDP and defended with DAD.
8.4. DNS Proxy Implementation 8.4. DNS Proxy Implementation
The CLAT SHOULD implement a DNS proxy as defined in [RFC5625]. The The CLAT SHOULD implement a DNS proxy as defined in [RFC5625]. The
case of an IPv4-only node behind the CLAT querying an IPv4 DNS server case of an IPv4-only node behind the CLAT querying an IPv4 DNS server
is undesirable since it requires both stateful and stateless is undesirable since it requires both stateful and stateless
translation for each DNS lookup. The CLAT SHOULD set itself as the translation for each DNS lookup. The CLAT SHOULD set itself as the
DNS server via DHCP or other means and proxy DNS queries for IPv4 and DNS server via DHCP or other means and proxy DNS queries for IPv4 and
IPv6 LAN clients. Using the CLAT enabled home router or UE as a DNS IPv6 LAN clients. Using the CLAT enabled home router or UE as a DNS
proxy is a normal consumer gateway function and simplifies the proxy is a normal consumer gateway function and simplifies the
skipping to change at page 14, line 7 skipping to change at page 10, line 28
2. If the ISP for end users can assign an IPv6 prefix greater than 2. If the ISP for end users can assign an IPv6 prefix greater than
/64 to each subscriber, this 464XLAT architecture can separate /64 to each subscriber, this 464XLAT architecture can separate
IPv6 prefix for native IPv6 packets and the XLAT prefixes for IPv6 prefix for native IPv6 packets and the XLAT prefixes for
IPv4/IPv6 translation packets. Accordingly, it can identify the IPv4/IPv6 translation packets. Accordingly, it can identify the
type of packets ("native IPv6 packets" and "IPv4/IPv6 translation type of packets ("native IPv6 packets" and "IPv4/IPv6 translation
packets"), and implement traffic engineering based on the IPv6 packets"), and implement traffic engineering based on the IPv6
prefix. prefix.
9.2. Traffic Treatment Scenarios 9.2. Traffic Treatment Scenarios
This 464XLAT architecture has capabilities. One is a IPv4 -> IPv6 -> The below table outlines how different permutations of connectivity
IPv4 translation for sharing global IPv4 addresses as a basic are treated in the 464XLAT architecture.
function, another, if combined with BIH [RFC6535], is a IPv4 -> IPv6
translation for reaching IPv6-only servers from IPv4-only clients NOTE: 464XLAT double translation treatment will be stateless when a
that can not support IPv6. IPv4-only clients must be support through dedicated /64 is available for translation on the CLAT. Otherwise,
the long period of global transition to IPv6. the CLAT will have both stateful and stateless since it requires
NAT44 from the LAN to a single IPv4 address and then stateless
translation to a single IPv6 address.
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| Server | Application | Traffic Treatment | Location of | | Server | Application | Traffic Treatment | Location of |
| | and Host | | Translation | | | and Host | | Translation |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| IPv6 | IPv6 | End-to-end IPv6 | None | | IPv6 | IPv6 | End-to-end IPv6 | None |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| IPv4 | IPv6 | Stateful Translation | PLAT | | IPv4 | IPv6 | Stateful Translation | PLAT |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| IPv4 | IPv4 | 464XLAT | PLAT/CLAT | | IPv4 | IPv4 | 464XLAT | PLAT/CLAT |
+--------+-------------+-----------------------+-------------+ +--------+-------------+-----------------------+-------------+
| IPv6 | IPv4 | BIH | CLAT |
+--------+-------------+-----------------------+-------------+
Traffic Treatment Scenarios Traffic Treatment Scenarios
The above chart shows most common traffic types and traffic
treatment.
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
IANA is requested to reserve a Modified EUI-64 identifier for 464XLAT This document has no actions for IANA.
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.
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, Colitti, Erik Kline, Ole Troan, Maoke Chen, Gang Chen, Tom Petch,
Jouni Korhonen, and Bjoern A. Zeeb for their helpful comments. Jouni Korhonen, Bjoern A. Zeeb, Hemant Singh, Vizdal Ales, Mark ZZZ
Special acknowledgments go to Remi Despres for his plentiful supports Smith, Mikael Abrahamsson, Tore Anderson, Teemu Savolainen, Alexandru
and suggestions, especially about using NAT44 with IANA's EUI-64 ID. Petrescu, Gert Doering, Victor Kuarsingh, Ray Hunter, James Woodyatt,
We also would like to thank Fred Baker and Joel Jaeggli for their and Tom Taylor for their helpful comments. Special acknowledgments
support. go to Remi Despres for his 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.
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,
October 2010. October 2010.
[RFC6144] Baker, F., Li, X., Bao, C., and K. Yin, "Framework for
IPv4/IPv6 Translation", RFC 6144, April 2011.
[RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation [RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation
Algorithm", RFC 6145, April 2011. Algorithm", RFC 6145, April 2011.
[RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful [RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful
NAT64: Network Address and Protocol Translation from IPv6 NAT64: Network Address and Protocol Translation from IPv6
Clients to IPv4 Servers", RFC 6146, April 2011. Clients to IPv4 Servers", RFC 6146, April 2011.
13.2. Informative References 13.2. Informative References
[I-D.hazeyama-widecamp-ipv6-only-experience]
Hazeyama, H., Hiromi, R., Ishihara, T., and O. Nakamura,
"Experiences from IPv6-Only Networks with Transition
Technologies in the WIDE Camp Spring 2012",
draft-hazeyama-widecamp-ipv6-only-experience-01 (work in
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-11 (work in draft-ietf-behave-nat64-discovery-heuristic-11 (work in
progress), July 2012. progress), July 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
(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
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.
[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.
[RFC6535] Huang, B., Deng, H., and T. Savolainen, "Dual-Stack Hosts
Using "Bump-in-the-Host" (BIH)", RFC 6535, February 2012.
[TS.23203] 3GPP, "Policy and charging control architecture", 3GPP [TS.23203] 3GPP, "Policy and charging control architecture", 3GPP
TS 23.203 10.7.0, June 2012. TS 23.203 10.7.0, June 2012.
Appendix A. Examples of IPv4/IPv6 Address Translation Appendix A. Examples of IPv4/IPv6 Address Translation
The following are examples of IPv4/IPv6 Address Translation on the The following is a example of IPv4/IPv6 Address Translation on the
464XLAT architecture. 464XLAT architecture.
Example 1. (Case of enabling only stateless XLATE on CLAT)
In the case that an IPv6 prefix greater than /64 is assigned to an In the case that an IPv6 prefix greater than /64 is assigned to an
end user by such as DHCPv6-PD [RFC3633], only the Stateless XLATE end user by such as DHCPv6-PD [RFC3633], the CLAT can use a dedicated
functionality should be enabled on the CLAT as the CLAT can use a /64 from the assigned IPv6 prefix.
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
+------------------------------+ +--------------------------------+ +------------------------------+ +--------------------------------+
^ | Destination IP address | ^ | Destination IP address |
| | [198.51.100.1] | | | [198.51.100.1] |
| | Source IP address | | | Source IP address |
| | [192.0.2.1] | | | [192.0.2.1] |
skipping to change at page 18, line 4 skipping to change at page 14, line 4
+------------------------------+ +--------------------------------+ +------------------------------+ +--------------------------------+
^ | Destination IP address | ^ | Destination IP address |
| | [198.51.100.1] | | | [198.51.100.1] |
| | Source IP address | | | Source IP address |
| | [192.168.1.2] | | | [192.168.1.2] |
+------------------------------+ +--------------------------------+ +------------------------------+ +--------------------------------+
| IPv4 client | | IPv4 client |
| [192.168.1.2/24] | | [192.168.1.2/24] |
+------------------------------+ +------------------------------+
Delegated IPv6 prefix for client: 2001:db8:aaaa::/56 Delegated IPv6 prefix for client: 2001:db8:aaaa::/56
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
+-------------------------------+ +-------------------------------+
^ | Destination IP address |
| | [198.51.100.1] |
| | Source IP address |
| | [192.0.2.1] |
+-------------------------------+ +-------------------------------+
| PLAT | ^
| IPv4 pool address | |
| [192.0.2.1 - 192.0.2.100] | |
| PLAT-side XLATE IPv6 prefix | |
| [2001:db8:1234::/96] | |
+-------------------------------+ +-------------------------------+
^ | Destination IP address |
| | [2001:db8:1234::198.51.100.1] |
| | Source IP address |
| | [2001:db8:aaaa:0:200:5e10::] |
+-------------------------------+ +-------------------------------+
| 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] | |
+ - - - - - - - - - - - - - - - + +-------------------------------+
| ^ | | Destination IP address |
| | | | [198.51.100.1] |
| | | | Source IP address |
| | | | [10.255.255.1] |
+ - - - - - - - - - - - - - - - + +-------------------------------+
| CLAT NAT44 function | ^
| - - - - - - - - - - - - - - - | |
| NAT44 NATed address | |
| [10.255.255.1/32] | |
+-------------------------------+ +-------------------------------+
^ | Destination IP address |
| | [198.51.100.1] |
| | Source IP address |
| | [192.168.1.2] |
+-------------------------------+ +-------------------------------+
| IPv4 client |
| [192.168.1.2/24] |
+-------------------------------+
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.
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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