Internet Engineering Task Force (IETF)                 J. Palet Martinez
Request for Comments: 8683                              The IPv6 Company
Category: Informational                                    November 2019
ISSN: 2070-1721

Additional Deployment Guidelines for NAT64/464XLAT in Operator and Enterprise Networks

オペレーターおよびエンタープライズネットワークにおけるNAT64 / 464XLATの追加の展開ガイドライン



This document describes how Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers (NAT64) (including 464XLAT) can be deployed in an IPv6 network -- whether it's cellular ISP, broadband ISP, or enterprise -- and the possible optimizations. This document also discusses issues to be considered when having IPv6-only connectivity, such as: a) DNS64, b) applications or devices that use literal IPv4 addresses or non-IPv6-compliant APIs, and c) IPv4-only hosts or applications.


Status of This Memo


This document is not an Internet Standards Track specification; it is published for informational purposes.

このドキュメントはInternet Standards Trackの仕様ではありません。情報提供を目的として公開されています。

This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are candidates for any level of Internet Standard; see Section 2 of RFC 7841.

このドキュメントは、IETF(Internet Engineering Task Force)の製品です。これは、IETFコミュニティのコンセンサスを表しています。公開レビューを受け、インターネットエンジニアリングステアリンググループ(IESG)による公開が承認されました。 IESGによって承認されたすべてのドキュメントが、あらゆるレベルのインターネット標準の候補であるとは限りません。 RFC 7841のセクション2をご覧ください。

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at


Copyright Notice


Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved.

Copyright(c)2019 IETF Trustおよびドキュメントの作成者として識別された人物。全著作権所有。

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents ( in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

この文書は、BCP 78およびIETF文書に関するIETFトラストの法的規定(の対象であり、この文書の発行日に有効です。これらのドキュメントは、このドキュメントに関するあなたの権利と制限を説明しているため、注意深く確認してください。このドキュメントから抽出されたコードコンポーネントには、Trust Legal Provisionsのセクション4.eに記載されているSimplified BSD Licenseテキストが含まれている必要があり、Simplified BSD Licenseに記載されているように保証なしで提供されます。

Table of Contents


   1.  Introduction
   2.  Requirements Language
   3.  NAT64 Deployment Scenarios
     3.1.  Known to Work
       3.1.1.  Service Provider NAT64 with DNS64
       3.1.2.  Service Provider Offering 464XLAT Using DNS64
       3.1.3.  Service Provider Offering 464XLAT, without Using DNS64
     3.2.  Known to Work under Special Conditions
       3.2.1.  Service Provider NAT64 without DNS64
       3.2.2.  Service-Provider NAT64; DNS64 in IPv6 Hosts
       3.2.3.  Service-Provider NAT64; DNS64 in the IPv4-Only Remote
     3.3.  Comparing the Scenarios
   4.  Issues to be Considered
     4.1.  DNSSEC Considerations and Possible Approaches
       4.1.1.  Not Using DNS64
       4.1.2.  DNSSEC Validator Aware of DNS64
       4.1.3.  Stub Validator
       4.1.4.  CLAT with DNS Proxy and Validator
       4.1.5.  ACL of Clients
       4.1.6.  Mapping Out IPv4 Addresses
     4.2.  DNS64 and Reverse Mapping
     4.3.  Using 464XLAT with/without DNS64
     4.4.  Foreign DNS
       4.4.1.  Manual Configuration of DNS
       4.4.2.  DNS Privacy/Encryption Mechanisms
       4.4.3.  Split DNS and VPNs
     4.5.  Well-Known Prefix (WKP) vs. Network-Specific Prefix (NSP)
     4.6.  IPv4 Literals and Non-IPv6-Compliant APIs
     4.7.  IPv4-Only Hosts or Applications
     4.8.  CLAT Translation Considerations
     4.9.  EAM Considerations
     4.10. Incoming Connections
   5.  Summary of Deployment Recommendations for NAT64/464XLAT
   6.  Deployment of 464XLAT/NAT64 in Enterprise Networks
   7.  Security Considerations
   8.  IANA Considerations
   9.  References
     9.1.  Normative References
     9.2.  Informative References
   Appendix A.  Example of Broadband Deployment with 464XLAT
   Appendix B.  CLAT Implementation
   Appendix C.  Benchmarking
   Author's Address
1. Introduction
1. はじめに

Stateful NAT64 [RFC6146] describes a stateful IPv6-to-IPv4 translation mechanism that allows IPv6-only hosts to communicate with IPv4-only servers using unicast UDP, TCP, or ICMP by means of IPv4 public address sharing among multiple IPv6-only hosts. Unless otherwise stated, references to NAT64 (function) in this document should be interpreted as Stateful NAT64.

ステートフルNAT64 [RFC6146]は、IPv6のみのホストが複数のIPv6のみのホスト間でIPv4パブリックアドレスを共有することにより、ユニキャストUDP、TCP、またはICMPを使用してIPv4のみのサーバーと通信できるようにする、ステートフルIPv6-to-IPv4変換メカニズムについて説明しています。特に明記されていない限り、このドキュメントでのNAT64(関数)への参照は、ステートフルNAT64として解釈されます。

The translation of the packet headers is done using the IP/ICMP translation algorithm defined in [RFC7915]; algorithmically translating the IPv4 addresses to IPv6 addresses, and vice versa, is done following [RFC6052].

パケットヘッダーの変換は、[RFC7915]で定義されているIP / ICMP変換アルゴリズムを使用して行われます。 IPv4アドレスをIPv6アドレスに、またはその逆にアルゴリズム的に変換することは、[RFC6052]に従って行われます。

DNS64 [RFC6147] is in charge of the synthesis of AAAA records from the A records, so it only works for applications making use of DNS. It was designed to avoid changes in both the IPv6-only hosts and the IPv4-only server, so they can use a NAT64 function. As discussed in Section 5.5 of [RFC6147], a security-aware and validating host has to perform the DNS64 function locally.

DNS64 [RFC6147]は、AレコードからのAAAAレコードの合成を担当するため、DNSを使用するアプリケーションでのみ機能します。これは、IPv6のみのホストとIPv4のみのサーバーの両方での変更を回避して、NAT64機能を使用できるように設計されています。 [RFC6147]のセクション5.5で説明されているように、セキュリティ対応および検証ホストはDNS64機能をローカルで実行する必要があります。

However, the use of NAT64 and/or DNS64 presents three drawbacks:


1. Because DNS64 [RFC6147] modifies DNS answers, and DNSSEC is designed to detect such modifications, DNS64 [RFC6147] may potentially break DNSSEC, depending on a number of factors such as the location of the DNS64 function (at a DNS server or validator, at the end host, ...), how it has been configured, if the end hosts are validating, etc.

1. DNS64 [RFC6147]はDNSの回答を変更し、DNSSECはそのような変更を検出するように設計されているため、DNS64 [RFC6147]は、DNS64関数の場所(DNSサーバーまたは検証サーバーでエンドホスト、...)、それがどのように構成されているか、エンドホストが検証している場合など。

2. Because of the need to use DNS64 [RFC6147] or an alternative "host/application built-in" mechanism for address synthesis, there may be an issue for NAT64 [RFC6146] because it doesn't work when IPv4 literal addresses or non-IPv6-compliant APIs are being used.

2. アドレス合成にDNS64 [RFC6147]または代替の「ホスト/アプリケーション組み込み」メカニズムを使用する必要があるため、IPv4リテラルアドレスまたは非IPv6の場合は機能しないため、NAT64 [RFC6146]に問題がある可能性があります。準拠のAPIが使用されています。

3. NAT64 alone was not designed to provide a solution for IPv4-only hosts or applications that are located within a network and connected to a service provider IPv6-only access link, as it was designed for a very specific scenario (see Section 2.1 of [RFC6144]).

3. NAT64のみは、非常に特定のシナリオ用に設計されたため、ネットワーク内にあり、サービスプロバイダーのIPv6のみのアクセスリンクに接続されているIPv4のみのホストまたはアプリケーションのソリューションを提供するようには設計されていません([RFC6144のセクション2.1を参照]。 ])。

The drawbacks discussed above may come into play if part of an enterprise network is connected to other parts of the same network or to third-party networks by means of IPv6-only connectivity. This is just an example that may apply to many other similar cases. All of them are deployment specific.


Accordingly, the use of "operator", "operator network", "service provider", and similar terms in this document are interchangeable with equivalent cases of enterprise networks; other cases may be similar as well. This may be also the case for "managed end-user networks".


Note that if all the hosts in a network were performing address synthesis, as described in Section 7.2 of [RFC6147], some of the drawbacks may not apply. However, it is unrealistic to expect that in today's world, considering the high number of devices and applications that aren't yet IPv6 enabled. In this document, the case in which all hosts provide synthesis will be considered only for specific scenarios that can guarantee it.


An analysis of stateful IPv4/IPv6 mechanisms is provided in [RFC6889].

ステートフルIPv4 / IPv6メカニズムの分析は[RFC6889]で提供されています。

This document looks into different possible NAT64 [RFC6146] deployment scenarios, including IPv4-IPv6-IPv4 (464 for short) and similar ones that were not documented in [RFC6144], such as 464XLAT [RFC6877] in operator (broadband and cellular) and enterprise networks; it provides guidelines to avoid operational issues.

このドキュメントでは、IPv4-IPv6-IPv4(略して464)や、[RFC6144]で文書化されていなかった、オペレーター(ブロードバンドおよびセルラー)の464XLAT [RFC6877]などの類似のシナリオを含む、さまざまなNAT64 [RFC6146]展開シナリオを検討します。エンタープライズネットワーク;運用上の問題を回避するためのガイドラインを提供します。

This document also explores the possible NAT64 deployment scenarios (split in "known to work" and "known to work under special conditions"), providing a quick and generic comparison table among them. Then, the document describes the issues that an operator needs to understand, which will allow the best approach/scenario to be defined for each specific network case. A summary provides some recommendations and decision points. A section with clarifications on the usage of this document for enterprise networks is also provided. Finally, Appendix A provides an example of a broadband deployment using 464XLAT and hints for a customer-side translator (CLAT) implementation.


[RFC7269] already provides information about NAT64 deployment options and experiences. This document and [RFC7269] are complementary; they both look into different deployment considerations. Furthermore, this document considers the updated deployment experience and newer standards.


The target deployment scenarios in this document may also be covered by other IPv4-as-a-Service (IPv4aaS) transition mechanisms. Note that this is true only for broadband networks; in the case of cellular networks, the only supported solution is the use of NAT64/464XLAT. So, it is out of scope of this document to provide a comparison among the different IPv4aaS transition mechanisms, which are analyzed in [IPv6-TRANSITION].

このドキュメントの対象となる展開シナリオは、他のIPv4-as-a-Service(IPv4aaS)移行メカニズムによってカバーされる場合もあります。これはブロードバンドネットワークにのみ当てはまることに注意してください。携帯電話ネットワークの場合、サポートされる唯一のソリューションはNAT64 / 464XLATの使用です。したがって、[IPv6-TRANSITION]で分析されているさまざまなIPv4aaS移行メカニズムを比較することは、このドキュメントの範囲外です。

Consequently, this document should not be used as a guide for an operator or enterprise to decide which IPv4aaS is the best one for its own network. Instead, it should be used as a tool for understanding all the implications, including relevant documents (or even specific parts of them) for the deployment of NAT64/464XLAT and for facilitating the decision process regarding specific deployment details.

したがって、このドキュメントは、オペレーターまたは企業が自社のネットワークに最適なIPv4aaSを決定するためのガイドとして使用しないでください。代わりに、NAT64 / 464XLATの展開に関する関連ドキュメント(またはドキュメントの特定の部分)を含むすべての影響を理解し、特定の展開の詳細に関する決定プロセスを容易にするためのツールとして使用する必要があります。

2. Requirements Language
2. 要件言語

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.


3. NAT64 Deployment Scenarios
3. NAT64展開シナリオ

DNS64 (see Section 7 of [RFC6147]) provides three deployment scenarios, depending on the location of the DNS64 function. However, since the publication of that document, other deployment scenarios and NAT64 use cases need to be considered in actual networks, despite the fact that some of them were specifically ruled out by the original NAT64/DNS64 work.

DNS64([RFC6147]のセクション7を参照)は、DNS64関数の場所に応じて、3つの展開シナリオを提供します。ただし、そのドキュメントの公開以降、元のNAT64 / DNS64の作業によって明確に除外されていたにもかかわらず、実際のネットワークでは他の展開シナリオとNAT64の使用例を考慮する必要があります。

Consequently, the perspective in this document is to broaden those scenarios and include a few new ones. However, in order to reduce the number of possible cases, we work under the assumption that the service provider wants to make sure that all the customers have a service without failures. This means considering the following assumptions for the worst possible case:


a. There are hosts that will be validating DNSSEC.

a. DNSSECを検証するホストがあります。

b. IPv4 literal addresses and non-IPv6-compliant APIs are being used.

b. IPv4リテラルアドレスと非IPv6準拠のAPIが使用されています。

c. There are IPv4-only hosts or applications beyond the IPv6-only link (e.g., tethering in cellular networks).

c. IPv6のみのリンクを超えたIPv4のみのホストまたはアプリケーション(たとえば、セルラーネットワークでのテザリング)があります。

This document uses a common set of possible "participant entities":


1. An IPv6-only access network (IPv6).

1. IPv6のみのアクセスネットワーク(IPv6)。

2. An IPv4-only remote network/server/service (IPv4).

2. IPv4のみのリモートネットワーク/サーバー/サービス(IPv4)。

3. A NAT64 function (NAT64) in the service provider.

3. サービスプロバイダーのNAT64関数(NAT64)。

4. A DNS64 function (DNS64) in the service provider.

4. サービスプロバイダーのDNS64関数(DNS64)。

5. An external service provider offering the NAT64 function and/or the DNS64 function (extNAT64/extDNS64).

5. NAT64機能またはDNS64機能(extNAT64 / extDNS64)を提供する外部サービスプロバイダー。

6. A 464XLAT customer-side translator (CLAT).

6. 464XLAT顧客側トランスレータ(CLAT)。

Note that the nomenclature used in parentheses is the one that, for short, will be used in the figures. Note: for simplicity, the boxes in the figures don't mean they are actually a single device; they represent one or more functions as located in that part of the network (i.e., a single box with NAT64 and DNS64 functions can actually be several devices, not just one).


The possible scenarios are split in two general categories:


1. Known to work.

1. 動作することが知られています。

2. Known to work under special conditions.

2. 特別な条件下で動作することが知られています。

3.1. Known to Work
3.1. 機能することがわかっている

The scenarios in this category are known to work, as there are well-known existing deployments from different operators using them. Each one may have different pros and cons, and in some cases, the trade-offs may be acceptable for some operators.


3.1.1. Service Provider NAT64 with DNS64
3.1.1. DNS64を使用するサービスプロバイダーNAT64

In this scenario (Figure 1), the service provider offers both the NAT64 and DNS64 functions.


This is the most common scenario as originally considered by the designers of NAT64 [RFC6146] and DNS64 [RFC6147]; however, it may also have the implications related to the DNSSEC.

これは、NAT64 [RFC6146]およびDNS64 [RFC6147]の設計者によって最初に検討された最も一般的なシナリオです。ただし、DNSSECに関連する可能性もあります。

This scenario may also fail to solve the issues of IPv4 literal addresses, non-IPv6-compliant APIs, or IPv4-only hosts or applications behind the IPv6-only access network.


           +----------+        +----------+        +----------+
           |          |        |  NAT64   |        |          |
           |   IPv6   +--------+    +     +--------+   IPv4   |
           |          |        |  DNS64   |        |          |
           +----------+        +----------+        +----------+

Figure 1: NAT64 with DNS64


A similar scenario (Figure 2) exists if the service provider offers only the DNS64 function; the NAT64 function is provided by an outsourcing agreement with an external provider. All the considerations in the previous paragraphs of this section are the same for this sub-case.

サービスプロバイダーがDNS64機能のみを提供する場合も、同様のシナリオ(図2)が存在します。 NAT64機能は、外部プロバイダーとのアウトソーシング契約によって提供されます。このセクションの前の段落のすべての考慮事項は、このサブケースでも同じです。

                               +----------+        +----------+
                               |          |        |          |
                               | extNAT64 +--------+   IPv4   |
                               |          |        |          |
                               +----+-----+        +----------+
           +----------+        +----+-----+
           |          |        |          |
           |   IPv6   +--------+  DNS64   +
           |          |        |          |
           +----------+        +----------+

Figure 2: NAT64 in an External Service Provider


This is equivalent to the scenario (Figure 3) where the outsourcing agreement with the external provider is to provide both the NAT64 and DNS64 functions. Once more, all the considerations in the previous paragraphs of this section are the same for this sub-case.


                                +----------+       +----------+
                                | extNAT64 |       |          |
                                |    +     +-------+   IPv4   |
                                | extDNS64 |       |          |
                                +----+-----+       +----------+
            +----------+             |
            |          |             |
            |   IPv6   +-------------+
            |          |

Figure 3: NAT64 and DNS64 in an External Provider


One additional equivalent scenario (Figure 4) exists if the service provider only offers the NAT64 function; the DNS64 function is from an external provider with or without a specific agreement among them. This is a common scenario today, as several "global" service providers provide free DNS/DNS64 services, and users often configure their DNS manually. This will only work if both the NAT64 and DNS64 functions are using the Well-Known Prefix (WKP) or the same Network-Specific Prefix (NSP). All the considerations in the previous paragraphs of this section are the same for this sub-case.

サービスプロバイダーがNAT64機能のみを提供している場合、同等のシナリオが1つ追加されます(図4)。 DNS64関数は、外部プロバイダーからのものであり、それらの間で特定の合意がある場合とない場合があります。これは今日の一般的なシナリオです。いくつかの「グローバル」サービスプロバイダーが無料のDNS / DNS64サービスを提供しており、ユーザーはDNSを手動で構成することがよくあります。これは、NAT64機能とDNS64機能の両方が既知のプレフィックス(WKP)または同じネットワーク固有のプレフィックス(NSP)を使用している場合にのみ機能します。このセクションの前の段落のすべての考慮事項は、このサブケースでも同じです。

Of course, if the external DNS64 function is agreed with the service provider, then this case is similar to the ones already depicted in this scenario.


                               |          |
                               | extDNS64 |
                               |          |
           +----------+        +----+-----+        +----------+
           |          |        |          |        |          |
           |   IPv6   +--------+  NAT64   +--------+   IPv4   |
           |          |        |          |        |          |
           +----------+        +----------+        +----------+

Figure 4: NAT64; DNS64 by an External Provider


3.1.2. Service Provider Offering 464XLAT Using DNS64
3.1.2. DNS64を使用して464XLATを提供するサービスプロバイダー

464XLAT [RFC6877] describes an architecture that provides IPv4 connectivity across a network, or part of it, when it is only natively transporting IPv6. The need to support the CLAT function in order to ensure the IPv4 service continuity in IPv6-only cellular deployments has been suggested in [RFC7849].

464XLAT [RFC6877]は、IPv6をネイティブにのみ転送する場合に、ネットワーク全体またはその一部にIPv4接続を提供するアーキテクチャについて説明しています。 [RFC7849]では、IPv6のみのセルラー展開でIPv4サービスの継続性を確保するためにCLAT機能をサポートする必要性が示唆されています。

In order to do that, 464XLAT [RFC6877] relies on the combination of existing protocols:

そのために、464XLAT [RFC6877]は既存のプロトコルの組み合わせに依存しています。

1. The CLAT is a stateless IPv4-to-IPv6 translator (NAT46) [RFC7915] implemented in the end-user device or Customer Edge Router (CE), located at the "customer edge" of the network.

1. CLATは、ネットワークの「カスタマーエッジ」にあるエンドユーザーデバイスまたはカスタマーエッジルーター(CE)に実装されているステートレスIPv4-to-IPv6トランスレーター(NAT46)[RFC7915]です。

2. The provider-side translator (PLAT) is a stateful NAT64 [RFC6146], implemented typically in the operator network.

2. プロバイダー側​​トランスレーター(PLAT)は、通常はオペレーターネットワークで実装されるステートフルNAT64 [RFC6146]です。

3. Optionally, DNS64 [RFC6147] may allow an optimization: a single translation at the NAT64, instead of two translations (NAT46+NAT64), when the application at the end-user device supports IPv6 DNS (uses AAAA Resource Records).

3. オプションで、DNS64 [RFC6147]は最適化を許可する場合があります。エンドユーザーデバイスのアプリケーションがIPv6 DNSをサポートする場合(AAAAリソースレコードを使用)、2つの変換(NAT46 + NAT64)ではなく、NAT64での単一の変換です。

Note that even if the provider-side translator is referred to as PLAT in the 464XLAT terminology [RFC6877], for simplicity and uniformity across this document, it is always referred to as NAT64 (function).


In this scenario (Figure 5), the service provider deploys 464XLAT with a DNS64 function.


As a consequence, the DNSSEC issues remain, unless the host is doing the address synthesis.


464XLAT [RFC6877] is a very simple approach to cope with the major NAT64+DNS64 drawback: not working with applications or devices that use literal IPv4 addresses or non-IPv6-compliant APIs.

464XLAT [RFC6877]は、NAT64 + DNS64の主な欠点に対処するための非常に単純なアプローチです。リテラルIPv4アドレスまたは非IPv6準拠のAPIを使用するアプリケーションまたはデバイスでは機能しません。

464XLAT [RFC6877] has been used mainly in IPv6-only cellular networks. By supporting a CLAT function, end-user device applications can access IPv4-only end networks / applications, despite the fact that those applications or devices use literal IPv4 addresses or non-IPv6-compliant APIs.

464XLAT [RFC6877]は、主にIPv6のみのセルラーネットワークで使用されています。 CLAT機能をサポートすることにより、エンドユーザーデバイスアプリケーションは、IPv4のみのエンドネットワーク/アプリケーションにアクセスできます。これらのアプリケーションまたはデバイスは、リテラルIPv4アドレスまたは非IPv6準拠のAPIを使用しています。

In addition, in the cellular network example above, if the User Equipment (UE) provides tethering, other devices behind it will be presented with a traditional Network Address Translation from IPv4 to IPv4 (NAT44), in addition to the native IPv6 support, so clearly it allows IPv4-only hosts behind the IPv6-only access network.


Furthermore, as discussed in [RFC6877], 464XLAT can be used in broadband IPv6 network architectures, by implementing the CLAT function at the CE.


The support of this scenario in a network offers two additional advantages:


* DNS load optimization: A CLAT should implement a DNS proxy (per [RFC5625]) so that only IPv6-native queries and AAAA records are sent to the DNS64 server. Otherwise, doubling the number of queries may impact the DNS infrastructure.

* DNS負荷の最適化:IPv6ネイティブクエリとAAAAレコードのみがDNS64サーバーに送信されるように、CLATは([RFC5625]に従って)DNSプロキシを実装する必要があります。それ以外の場合、クエリの数を2倍にすると、DNSインフラストラクチャに影響を与える可能性があります。

* Connection establishment delay optimization: If the UE/CE implementation is detecting the presence of a DNS64 function, it may issue only the AAAA query, instead of both the AAAA and A queries.

* 接続確立遅延の最適化:UE / CE実装がDNS64関数の存在を検出している場合、AAAAクエリとAクエリの両方ではなく、AAAAクエリのみを発行する場合があります。

In order to understand all the communication possibilities, let's assume the following representation of two dual-stack (DS) peers:


                   +-------+     .-----.                     .-----.
                   |       |    /       \                   /       \
       .-----.     | Res./ |   /  IPv6-  \     .-----.     /  IPv4-  \
      / Local \    | SOHO  +--(   only    )---( NAT64 )---(   only    )
     /         \   |       |   \  flow   /\    `-----'     \  flow   /
    (   Dual-   )--+ IPv6  |    \       /  \              / \       /
     \  Stack  /   |  CE   |     `--+--'    \   .-----.  /   `--+--'
      \ Peer  /    | with  |        |        \ / Remote\/       |
       `-----'     | CLAT  |    +---+----+    /         \    +---+----+
                   |       |    |DNS/IPv6|   (   Dual-   )   |DNS/IPv4|
                   +-------+    |  with  |    \  Stack  /    +--------+
                                | DNS64  |     \ Peer  /
                                +--------+      `-----'

Figure A: Representation of 464XLAT among Two Peers with DNS64


In this case, the possible communication paths, among the IPv4/IPv6 stacks of both peers, are as follows:

この場合、両方のピアのIPv4 / IPv6スタック間で可能な通信パスは次のとおりです。

a. Local-IPv6 to Remote-IPv6: Regular DNS and native IPv6 among peers.

a. ローカルIPv6からリモートIPv6:ピア間の通常のDNSおよびネイティブIPv6。

b. Local-IPv6 to Remote-IPv4: DNS64 and NAT64 translation.

b. ローカルIPv6からリモートIPv4へ:DNS64およびNAT64変換。

c. Local-IPv4 to Remote-IPv6: Not possible unless the CLAT implements Explicit Address Mappings (EAMs) as indicated by Section 4.9. In principle, it is not expected that services are deployed in the Internet when using IPv6 only, unless there is certainty that peers will also be IPv6 capable.

c. ローカルIPv4からリモートIPv6へ:CLATがセクション4.9で示すように明示的アドレスマッピング(EAM)を実装しない限り、不可能です。原則として、ピアもIPv6対応であることが確実でない限り、IPv6のみを使用する場合にインターネットでサービスが展開されることは想定されていません。

d. Local-IPv4 to Remote-IPv4: DNS64, CLAT, and NAT64 translations.

d. ローカルIPv4からリモートIPv4へ:DNS64、CLAT、およびNAT64変換。

e. Local-IPv4 to Remote-dual-stack using EAM optimization: If the CLAT implements EAM as indicated by Section 4.9, instead of using the path d. above, NAT64 translation is avoided, and the flow will use IPv6 from the CLAT to the destination.

e. EAM最適化を使用したローカルIPv4からリモートデュアルスタックへ:CLATがセクション4.9で示すようにEAMを実装する場合、パスdを使用する代わりに。上記では、NAT64変換は回避され、フローはCLATから宛先へのIPv6を使用します。

The rest of the figures in this section show different choices for placing the different elements.


           +----------+        +----------+        +----------+
           |   IPv6   |        |  NAT64   |        |          |
           |     +    +--------+    +     +--------+   IPv4   |
           |   CLAT   |        |  DNS64   |        |          |
           +----------+        +----------+        +----------+

Figure 5: 464XLAT with DNS64


A similar scenario (Figure 6) exists if the service provider only offers the DNS64 function; the NAT64 function is provided by an outsourcing agreement with an external provider. All the considerations in the previous paragraphs of this section are the same for this sub-case.

サービスプロバイダーがDNS64機能のみを提供している場合も、同様のシナリオ(図6)が存在します。 NAT64機能は、外部プロバイダーとのアウトソーシング契約によって提供されます。このセクションの前の段落のすべての考慮事項は、このサブケースでも同じです。

                               +----------+        +----------+
                               |          |        |          |
                               | extNAT64 +--------+   IPv4   |
                               |          |        |          |
                               +----+-----+        +----------+
           +----------+        +----+-----+
           |   IPv6   |        |          |
           |     +    +--------+  DNS64   +
           |   CLAT   |        |          |
           +----------+        +----------+

Figure 6: 464XLAT with DNS64; NAT64 in an External Provider


In addition, it is equivalent to the scenario (Figure 7) where the outsourcing agreement with the external provider is to provide both the NAT64 and DNS64 functions. Once more, all the considerations in the previous paragraphs of this section are the same for this sub-case.


                               +----------+        +----------+
                               | extNAT64 |        |          |
                               |    +     +--------+   IPv4   |
                               | extDNS64 |        |          |
                               +----+-----+        +----------+
           +----------+             |
           |   IPv6   |             |
           |     +    +-------------+
           |   CLAT   |

Figure 7: 464XLAT with DNS64; NAT64 and DNS64 in an External Provider


3.1.3. Service Provider Offering 464XLAT, without Using DNS64
3.1.3. DNS64を使用せずに464XLATを提供するサービスプロバイダー

The major advantage of this scenario (Figure 8), using 464XLAT without DNS64, is that the service provider ensures that DNSSEC is never broken, even if the user modifies the DNS configuration. Nevertheless, some CLAT implementations or applications may impose an extra delay, which is induced by the dual A/AAAA queries (and the wait for both responses), unless Happy Eyeballs v2 [RFC8305] is also present.

DNS64を使用せずに464XLATを使用するこのシナリオ(図8)の主な利点は、ユーザーがDNS構成を変更した場合でも、サービスプロバイダーがDNSSECが破損しないことを保証することです。それでも、Happy Eyeballs v2 [RFC8305]が存在しない場合を除き、一部のCLAT実装またはアプリケーションは、デュアルA / AAAAクエリ(および両方の応答の待機)によって引き起こされる追加の遅延を課す場合があります。

A possible variation of this scenario is when DNS64 is used only for the discovery of the NAT64 prefix. In the rest of the document, it is not considered a different scenario because once the prefix has been discovered, the DNS64 function is not used, so it behaves as if the DNS64 synthesis function is not present.


In this scenario, as in the previous one, there are no issues related to IPv4-only hosts (or IPv4-only applications) behind the IPv6-only access network, as neither are related to the usage of IPv4 literals or non-IPv6-compliant APIs.


The support of this scenario in a network offers one advantage:


* DNS load optimization: A CLAT should implement a DNS proxy (per [RFC5625]) so that only IPv6 native queries are sent to the DNS64 server. Otherwise, doubling the number of queries may impact the DNS infrastructure.

* DNS負荷の最適化:IPv6ネイティブクエリのみがDNS64サーバーに送信されるように、CLATは([RFC5625]に従って)DNSプロキシを実装する必要があります。それ以外の場合、クエリの数を2倍にすると、DNSインフラストラクチャに影響を与える可能性があります。

As indicated earlier, the connection establishment delay optimization is achieved only in the case of devices, Operating Systems, or applications that use Happy Eyeballs v2 [RFC8305], which is very common.

前述のように、接続確立遅延の最適化は、Happy Eyeballs v2 [RFC8305]を使用するデバイス、オペレーティングシステム、またはアプリケーションの場合にのみ達成されます。これは非常に一般的です。

As in the previous case, let's assume the representation of two dual-stack peers:


                   +-------+     .-----.                     .-----.
                   |       |    /       \                   /       \
       .-----.     | Res./ |   /  IPv6-  \     .-----.     /  IPv4-  \
      / Local \    | SOHO  +--(   only    )---( NAT64 )---(   only    )
     /         \   |       |   \  flow   /\    `-----'     \  flow   /
    (   Dual-   )--+ IPv6  |    \       /  \              / \       /
     \  Stack  /   |  CE   |     `--+--'    \   .-----.  /   `--+--'
      \ Peer  /    | with  |        |        \ / Remote\/       |
       `-----'     | CLAT  |    +---+----+    /         \    +---+----+
                   |       |    |DNS/IPv6|   (   Dual-   )   |DNS/IPv4|
                   +-------+    +--------+    \  Stack  /    +--------+
                                               \ Peer  /

Figure B: Representation of 464XLAT among Two Peers without DNS64


In this case, the possible communication paths, among the IPv4/IPv6 stacks of both peers, are as follows:

この場合、両方のピアのIPv4 / IPv6スタック間で可能な通信パスは次のとおりです。

a. Local-IPv6 to Remote-IPv6: Regular DNS and native IPv6 among peers.

a. ローカルIPv6からリモートIPv6:ピア間の通常のDNSおよびネイティブIPv6。

b. Local-IPv6 to Remote-IPv4: Regular DNS, CLAT, and NAT64 translations.

b. ローカルIPv6からリモートIPv4へ:通常のDNS、CLAT、およびNAT64変換。

c. Local-IPv4 to Remote-IPv6: Not possible unless the CLAT implements EAM as indicated by Section 4.9. In principle, it is not expected that services are deployed in the Internet using IPv6 only, unless there is certainty that peers will also be IPv6-capable.

c. ローカルIPv4からリモートIPv6へ:CLATがセクション4.9で示すようにEAMを実装しない限り、不可能です。原則として、ピアもIPv6対応であることが確実でない限り、サービスがIPv6のみを使用してインターネットに展開されることは想定されていません。

d. Local-IPv4 to Remote-IPv4: Regular DNS, CLAT, and NAT64 translations.

d. ローカルIPv4からリモートIPv4へ:通常のDNS、CLAT、およびNAT64変換。

e. Local-IPv4 to Remote-dual-stack using EAM optimization: If the CLAT implements EAM as indicated by Section 4.9, instead of using the path d. above, NAT64 translation is avoided, and the flow will use IPv6 from the CLAT to the destination.

e. EAM最適化を使用したローカルIPv4からリモートデュアルスタックへ:CLATがセクション4.9で示すようにEAMを実装する場合、パスdを使用する代わりに。上記では、NAT64変換は回避され、フローはCLATから宛先へのIPv6を使用します。

Notice that this scenario works while the local hosts/applications are dual stack (which is the current situation) because the connectivity from a local IPv6 to a remote IPv4 is not possible without a AAAA synthesis. This aspect is important only when there are IPv6-only hosts in the LANs behind the CLAT and they need to communicate with remote IPv4-only hosts. However, it is not a sensible approach from an Operating System or application vendor perspective to provide IPv6-only support unless, similar to case c above, there is certainty of peers supporting IPv6 as well. An approach to a solution for this is also presented in [OPT-464XLAT].


The following figures show different choices for placing the different elements.


           +----------+        +----------+        +----------+
           |   IPv6   |        |          |        |          |
           |     +    +--------+  NAT64   +--------+   IPv4   |
           |   CLAT   |        |          |        |          |
           +----------+        +----------+        +----------+

Figure 8: 464XLAT without DNS64


This is equivalent to the scenario (Figure 9) where there is an outsourcing agreement with an external provider for the NAT64 function. All the considerations in the previous paragraphs of this section are the same for this sub-case.


                               +----------+        +----------+
                               |          |        |          |
                               | extNAT64 +--------+   IPv4   |
                               |          |        |          |
                               +----+-----+        +----------+
           +----------+             |
           |   IPv6   |             |
           |     +    +-------------+
           |   CLAT   |

Figure 9: 464XLAT without DNS64; NAT64 in an External Provider


3.2. Known to Work under Special Conditions
3.2. 特別な条件下で動作することがわかっている

The scenarios in this category are known not to work unless significant effort is devoted to solving the issues or they are intended to solve problems across "closed" networks instead of as a general Internet access usage. Even though some of the different pros, cons, and trade-offs may be acceptable, operators have implementation difficulties, as their expectations of NAT64/DNS64 are beyond the original intent.

このカテゴリのシナリオは、問題の解決に多大な労力が費やされない限り、または一般的なインターネットアクセスの使用ではなく、「閉じた」ネットワーク全体の問題を解決することを目的としない限り、機能しないことがわかっています。さまざまな長所、短所、およびトレードオフの一部は許容できるかもしれませんが、NAT64 / DNS64に対する期待が当初の意図を超えているため、オペレーターは実装に困難を抱えています。

3.2.1. Service Provider NAT64 without DNS64
3.2.1. DNS64なしのサービスプロバイダーNAT64

In this scenario (Figure 10), the service provider offers a NAT64 function; however, there is no DNS64 function support at all.


As a consequence, an IPv6 host in the IPv6-only access network will not be able to detect the presence of DNS64 by means of [RFC7050] or learn the IPv6 prefix to be used for the NAT64 function.


This can be sorted out as indicated in Section 4.1.1.


Regardless, because of the lack of the DNS64 function, the IPv6 host will not be able to obtain AAAA synthesized records, so the NAT64 function becomes useless.


An exception to this "useless" scenario is to manually configure mappings between the A records of each of the IPv4-only remote hosts and the corresponding AAAA records with the WKP or NSP used by the service-provider NAT64 function, as if they were synthesized by a DNS64 function.

この「役に立たない」シナリオの例外は、IPv4のみの各リモートホストのAレコードと、サービスプロバイダーのNAT64関数で使用されるWKPまたはNSPを使用して対応するAAAAレコード間のマッピングを手動で構成することです。 DNS64関数による。

This mapping could be done by several means, typically at the authoritative DNS server or at the service-provider resolvers by means of DNS Response Policy Zones (RPZs) [DNS-RPZ] or equivalent functionality. DNS RPZ may have implications in DNSSEC if the zone is signed. Also, if the service provider is using an NSP, having the mapping at the authoritative server may create troubles for other parties trying to use a different NSP or WKP, unless multiple DNS "views" (split-DNS) are also being used at the authoritative servers.

このマッピングは、いくつかの方法で行うことができます。通常は、権威DNSサーバーまたはサービスプロバイダーリゾルバーで、DNS応答ポリシーゾーン(RPZ)[DNS-RPZ]または同等の機能を使用します。ゾーンが署名されている場合、DNS RPZはDNSSECに影響を与える可能性があります。また、サービスプロバイダーがNSPを使用している場合、権限のあるサーバーでマッピングを行うと、複数のDNS "ビュー"(スプリットDNS)も使用されていない限り、他の当事者が別のNSPまたはWKPを使用しようとすると問題が発生する可能性があります。権限のあるサーバー。

Generally, the mappings alternative will only make sense if a few sets of IPv4-only remote hosts need to be accessed by a single network (or a small number of them), which supports IPv6 only in the access. This will require some kind of mutual agreement for using this procedure; this should not be a problem because it won't interfere with Internet use (which is a "closed service").


In any case, this scenario doesn't solve the issue of IPv4 literal addresses, non-IPv6-compliant APIs, or IPv4-only hosts within that IPv6-only access network.


           +----------+        +----------+        +----------+
           |          |        |          |        |          |
           |   IPv6   +--------+  NAT64   +--------+   IPv4   |
           |          |        |          |        |          |
           +----------+        +----------+        +----------+

Figure 10: NAT64 without DNS64


3.2.2. Service-Provider NAT64; DNS64 in IPv6 Hosts
3.2.2. サービスプロバイダーNAT64; IPv6ホストのDNS64

In this scenario (Figure 11), the service provider offers the NAT64 function but not the DNS64 function. However, the IPv6 hosts have a built-in DNS64 function.


This may become common if the DNS64 function is implemented in all the IPv6 hosts/stacks. This is not common at the time of writing but may become more common in the near future. This way, the DNSSEC validation is performed on the A record, and then the host can use the DNS64 function in order to use the NAT64 function without any DNSSEC issues.


This scenario fails to solve the issue of IPv4 literal addresses or non-IPv6-compliant APIs, unless the IPv6 hosts also support Happy Eyeballs v2 (Section 7.1 of [RFC8305]).

このシナリオでは、IPv6ホストがHappy Eyeballs v2([RFC8305]のセクション7.1)もサポートしていない限り、IPv4リテラルアドレスまたは非IPv6準拠のAPIの問題を解決できません。

Moreover, this scenario also fails to solve the problem of IPv4-only hosts or applications behind the IPv6-only access network.


           +----------+        +----------+        +----------+
           |   IPv6   |        |          |        |          |
           |     +    +--------+  NAT64   +--------+   IPv4   |
           |   DNS64  |        |          |        |          |
           +----------+        +----------+        +----------+

Figure 11: NAT64; DNS64 in IPv6 Hosts

図11:NAT64; IPv6ホストのDNS64

3.2.3. Service-Provider NAT64; DNS64 in the IPv4-Only Remote Network
3.2.3. サービスプロバイダーNAT64; IPv4のみのリモートネットワークのDNS64

In this scenario (Figure 12), the service provider offers the NAT64 function only. The IPv4-only remote network offers the DNS64 function.

このシナリオ(図12)では、サービスプロバイダーはNAT64機能のみを提供します。 IPv4のみのリモートネットワークはDNS64機能を提供します。

This is not common, and it doesn't make sense that a remote network, not deploying IPv6, is providing a DNS64 function. Like the scenario depicted in Section 3.2.1, it will only work if both sides are using the WKP or the same NSP, so the same considerations apply. It can also be tuned to behave as in Section 3.1.1.


This scenario fails to solve the issue of IPv4 literal addresses or non-IPv6-compliant APIs.


Moreover, this scenario also fails to solve the problem of IPv4-only hosts or applications behind the IPv6-only access network.


           +----------+        +----------+        +----------+
           |          |        |          |        |   IPv4   |
           |   IPv6   +--------+  NAT64   +--------+     +    |
           |          |        |          |        |   DNS64  |
           +----------+        +----------+        +----------+

Figure 12: NAT64; DNS64 in IPv4-Only Hosts

図12:NAT64; IPv4専用ホストのDNS64

3.3. Comparing the Scenarios
3.3. シナリオの比較

This section compares the different scenarios, including possible variations (each one represented in the previous sections by a different figure), while considering the following criteria:


a. DNSSEC: Are there hosts validating DNSSEC?

a. DNSSEC:DNSSECを検証するホストはありますか?

b. Literal/APIs: Are there applications using IPv4 literals or non-IPv6-compliant APIs?

b. リテラル/ API:IPv4リテラルまたは非IPv6準拠のAPIを使用するアプリケーションはありますか?

c. IPv4 only: Are there hosts or applications using IPv4 only?

c. IPv4のみ:IPv4のみを使用するホストまたはアプリケーションはありますか?

d. Foreign DNS: Does the scenario survive if the user, Operating System, applications, or devices change the DNS?

d. 外部DNS:ユーザー、オペレーティングシステム、アプリケーション、またはデバイスがDNSを変更しても、シナリオは存続しますか?

e. DNS load opt. (DNS load optimization): Are there extra queries that may impact the DNS infrastructure?

e. DNSロードオプション(DNS負荷の最適化):DNSインフラストラクチャに影響を与える可能性のある追加のクエリはありますか?

f. Connect. opt. (connection establishment delay optimization): Is the UE/CE only issuing the AAAA query or also the A query and waiting for both responses?

f. 接続します。選ぶ。 (接続確立遅延の最適化):UE / CEはAAAAクエリのみを発行しますか、それともAクエリも発行し、両方の応答を待機していますか?

In the table below, the columns represent each of the scenarios from the previous sections by the figure number. The possible values are as follows:


"-" means the scenario is "bad" for that criterion.


"+" means the scenario is "good" for that criterion.


"*" means the scenario is "bad" for that criterion; however, it is typically resolved with the support of Happy Eyeballs v2 [RFC8305].

「*」は、シナリオがその基準に対して「悪い」ことを意味します。ただし、通常はHappy Eyeballs v2 [RFC8305]のサポートにより解決されます。

In some cases, "countermeasures", alternative or special configurations, may be available for the criterion designated as "bad". So, this comparison is considering a generic case as a quick comparison guide. In some cases, a "bad" criterion is not necessarily a negative aspect; it all depends on the specific needs/ characteristics of the network where the deployment will take place. For instance, in a network that only has IPv6-only hosts and apps using DNS and IPv6-compliant APIs, there is no impact using only NAT64 and DNS64, but if the hosts validate DNSSEC, that criterion is still relevant.


   | Item / Figure | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
   | DNSSEC        | - | - | - | - | - | - | - | + | + | +  | +  | +  |
   | Literal/APIs  | - | - | - | - | + | + | + | + | + | -  | -  | -  |
   | IPv4-only     | - | - | - | - | + | + | + | + | + | -  | -  | -  |
   | Foreign DNS   | - | - | - | - | + | + | + | + | + | -  | +  | -  |
   | DNS load opt. | + | + | + | + | + | + | + | + | + | +  | +  | +  |
   | Connect. opt. | + | + | + | + | + | + | + | * | * | +  | +  | +  |

Table 1: Scenario Comparison


As a general conclusion, we should note if the network must support applications using any of the following:


* IPv4 literals

* IPv4リテラル

* non-IPv6-compliant APIs

* 非IPv6準拠API

* IPv4-only hosts or applications

* IPv4のみのホストまたはアプリケーション

Then, only the scenarios with 464XLAT, a CLAT function, or equivalent built-in local address synthesis features will provide a valid solution. Furthermore, those scenarios will also keep working if the DNS configuration is modified. Clearly, depending on if DNS64 is used or not, DNSSEC may be broken for those hosts doing DNSSEC validation.


All the scenarios are good in terms of DNS load optimization, and in the case of 464XLAT, it may provide an extra degree of optimization. Finally, all of the scenarios are also good in terms of connection establishment delay optimization. However, in the case of 464XLAT without DNS64, the usage of Happy Eyeballs v2 is required. This is not an issue as it is commonly available in actual Operating Systems.

すべてのシナリオはDNS負荷の最適化の点で優れており、464XLATの場合は、追加の最適化が提供される可能性があります。最後に、すべてのシナリオは、接続確立遅延の最適化の点でも優れています。ただし、DNS64を使用しない464XLATの場合、Happy Eyeballs v2の使用が必要です。これは実際のオペレーティングシステムで一般的に利用できるため、問題ではありません。

4. Issues to be Considered
4. 考慮すべき問題

This section reviews the different issues that an operator needs to consider for a NAT64/464XLAT deployment, as they may develop specific decision points about how to approach that deployment.

このセクションでは、NAT64 / 464XLATの展開についてオペレーターが検討する必要のあるさまざまな問題について説明します。これらの問題は、展開へのアプローチ方法に関する特定の決定ポイントを開発する可能性があるためです。

4.1. DNSSEC Considerations and Possible Approaches
4.1. DNSSECの考慮事項と可能なアプローチ

As indicated in the security considerations for DNS64 (see Section 8 of [RFC6147]) because DNS64 modifies DNS answers and DNSSEC is designed to detect such modifications, DNS64 may break DNSSEC.


When a device connected to an IPv6-only access network queries for a domain name in a signed zone, by means of a recursive name server that supports DNS64, the result may be a synthesized AAAA record. In that case, if the recursive name server is configured to perform DNSSEC validation and has a valid chain of trust to the zone in question, it will cryptographically validate the negative response from the authoritative name server. This is the expected DNS64 behavior: the recursive name server actually "lies" to the client device. However, in most of the cases, the client will not notice it, because generally, they don't perform validation themselves; instead, they rely on the recursive name servers.


In fact, a validating DNS64 resolver increases the confidence on the synthetic AAAA, as it has validated that a non-synthetic AAAA doesn't exist. However, if the client device is oblivious to NAT64 (the most common case) and performs DNSSEC validation on the AAAA record, it will fail as it is a synthesized record.


The best possible scenario from a DNSSEC point of view is when the client requests that the DNS64 server perform the DNSSEC validation (by setting the DNSSEC OK (DO) bit to 1 and the CD bit to 0). In this case, the DNS64 server validates the data; thus, tampering may only happen inside the DNS64 server (which is considered as a trusted part, thus, its likelihood is low) or between the DNS64 server and the client. All other parts of the system (including transmission and caching) are protected by DNSSEC [Threat-DNS64].

DNSSECの観点から考えられる最良のシナリオは、クライアントがDNS64サーバーにDNSSEC検証を実行するように要求する場合です(DNSSEC OK(DO)ビットを1に、CDビットを0に設定することによって)。この場合、DNS64サーバーはデータを検証します。したがって、改ざんはDNS64サーバー内(信頼された部分と見なされるため、その可能性は低い)またはDNS64サーバーとクライアントの間でのみ発生する可能性があります。システムの他のすべての部分(送信とキャッシングを含む)は、DNSSEC [Threat-DNS64]によって保護されています。

Similarly, if the client querying the recursive name server is another name server configured to use it as a forwarder, and it is performing DNSSEC validation, it will also fail on any synthesized AAAA record.


All those considerations are extensively covered in Sections 3, 5.5, and 6.2 of [RFC6147].


DNSSEC issues could be avoided if all the signed zones provide IPv6 connectivity together with the corresponding AAAA records. However, this is out of the control of the operator needing to deploy a NAT64 function. This has been proposed already in [DNS-DNSSEC].


An alternative solution, which was considered while developing [RFC6147], is that the validators will be DNS64 aware. Then, they can perform the necessary discovery and do their own synthesis. Since that was standardized sufficiently early in the validator deployment curve, the expectation was that it would be okay to break certain DNSSEC assumptions for networks that were stuck and really needing NAT64/DNS64.

[RFC6147]の開発中に検討された代替ソリューションは、バリデーターがDNS64を認識することです。その後、必要な発見を実行し、独自の合成を行うことができます。これはバリデーターの展開曲線の早い段階で十分に標準化されていたため、スタックしていてNAT64 / DNS64を実際に必要とするネットワークについて、特定のDNSSECの仮定を破っても大丈夫であると予想されていました。

As already indicated, the scenarios in the previous section are simplified to look at the worst possible case and for the most perfect approach. A DNSSEC breach will not happen if the end host is not doing validation.


The figures in previous studies indicate that DNSSEC broken by using DNS64 makes up about 1.7% [About-DNS64] of the cases. However, we can't negate that this may increase as DNSSEC deployment grows. Consequently, a decision point for the operator must depend on the following question: Do I really care about that percentage of cases and the impact on my help desk, or can I provide alternative solutions for them? Some possible solutions may be exist, as depicted in the next sections.


4.1.1. Not Using DNS64
4.1.1. DNS64を使用しない

One solution is to avoid using DNS64, but as already indicated, this is not possible in all the scenarios.


The use of DNS64 is a key component for some networks, in order to comply with traffic performance metrics, monitored by some governmental bodies and other institutions [FCC] [ARCEP].

DNS64の使用は、一部の政府機関や他の機関[FCC] [ARCEP]によって監視されるトラフィックパフォーマンスメトリックに準拠するために、一部のネットワークにとって重要なコンポーネントです。

One drawback of not having a DNS64 on the network side is that it's not possible to heuristically discover NAT64 [RFC7050]. Consequently, an IPv6 host behind the IPv6-only access network will not be able to detect the presence of the NAT64 function, nor learn the IPv6 prefix to be used for it, unless it is configured by alternative means.

ネットワーク側にDNS64がないことの1つの欠点は、NAT64 [RFC7050]を発見的に発見できないことです。その結果、IPv6のみのアクセスネットワークの背後にあるIPv6ホストは、NAT64機能の存在を検出できず、代替手段で構成されていない限り、IPv6プレフィックスを使用することを学習できません。

The discovery of the IPv6 prefix could be solved, as described in [RFC7050], by means of adding the relevant AAAA records to the zone of the service-provider recursive servers, i.e., if using the WKP (64:ff9b::/96):

[RFC7050]で説明されているように、関連するAAAAレコードをipv4only.arpaに追加することにより、IPv6プレフィックスの発見を解決できます。サービスプロバイダーの再帰サーバーのゾーン、つまりWKP(64:ff9b :: / 96)を使用している場合: SOA . . 0 0 0 0 0 NS . AAAA 64:ff9b:: AAAA 64:ff9b:: A A。 SOA。 。 0 0 0 0 0。 NS。。 AAAA 64:ff9b ::。 AAAA 64:ff9b ::。。

An alternative option is the use of DNS RPZ [DNS-RPZ] or equivalent functionalities. Note that this may impact DNSSEC if the zone is signed.

代替オプションは、DNS RPZ [DNS-RPZ]または同等の機能の使用です。ゾーンが署名されている場合、これはDNSSECに影響を与える可能性があることに注意してください。

Another alternative, only valid in environments with support from the Port Control Protocol (PCP) (for both the hosts or CEs and for the service-provider network), is to follow "Discovering NAT64 IPv6 Prefixes Using the Port Control Protocol (PCP)" [RFC7225].

(ホストまたはCEとサービスプロバイダーネットワークの両方に対して)ポート制御プロトコル(PCP)からのサポートがある環境でのみ有効な別の代替方法は、「ポート制御プロトコル(PCP)を使用したNAT64 IPv6プレフィックスの検出」に従うことです。 [RFC7225]。

Other alternatives may be available in the future. All them are extensively discussed in [RFC7051]; however, due to the deployment evolution, many considerations from that document have changed. New options are being documented, such as using Router Advertising [PREF64] or DHCPv6 options [DHCPv6-OPTIONS].


Simultaneous support of several of the possible approaches is convenient and will ensure that clients with different ways to configure the NAT64 prefix successfully obtain it. This is also convenient even if DNS64 is being used.


Also of special relevance to this section is [IPV4ONLY-ARPA].


4.1.2. DNSSEC Validator Aware of DNS64
4.1.2. DNSSEC Validator Aware of DNS64

In general, by default, DNS servers with DNS64 function will not synthesize AAAA responses if the DO flag was set in the query.


In this case, since only an A record is available, if a CLAT function is present, the CLAT will, as in the case of literal IPv4 addresses, keep that traffic flow end to end as IPv4 so DNSSEC is not broken.


However, this will not work if a CLAT function is not present because the hosts will not be able to use IPv4 (which is the case for all the scenarios without 464XLAT).


4.1.3. Stub Validator
4.1.3. スタブバリデーター

If the DO flag is set and the client device performs DNSSEC validation, and the Checking Disabled (CD) flag is set for a query, the DNS64 recursive server will not synthesize AAAA responses. In this case, the client could perform the DNSSEC validation with the A record and then synthesize the AAAA responses [RFC6052]. For that to be possible, the client must have learned the NAT64 prefix beforehand using any of the available methods (see [RFC7050], [RFC7225], [PREF64], and [DHCPv6-OPTIONS]). This allows the client device to avoid using the DNS64 function and still use NAT64 even with DNSSEC.


If the end host is IPv4 only, this will not work if a CLAT function is not present (which is the case for all scenarios without 464XLAT).


Instead of a CLAT, some devices or Operating Systems may implement an equivalent function by using Bump-in-the-Host [RFC6535] as part of Happy Eyeballs v2 (see Section 7.1 of [RFC8305]). In this case, the considerations in the above paragraphs are also applicable.

CLATの代わりに、一部のデバイスまたはオペレーティングシステムは、Happy Eyeballs v2の一部としてBump-in-the-Host [RFC6535]を使用して同等の機能を実装する場合があります([RFC8305]のセクション7.1を参照)。この場合、上記の段落の考慮事項も適用されます。

4.1.4. CLAT with DNS Proxy and Validator
4.1.4. DNSプロキシとバリデーターを使用したCLAT

If a CE includes CLAT support and also a DNS proxy, as indicated in Section 6.4 of [RFC6877], the CE could behave as a stub validator on behalf of the client devices. Then, following the same approach described in Section 4.1.3, the DNS proxy will actually "lie" to the client devices, which, in most cases, will not be noticed unless they perform validation by themselves. Again, this allows the client devices to avoid the use of the DNS64 function but to still use NAT64 with DNSSEC.


Once more, this will not work without a CLAT function (which is the case for all scenarios without 464XLAT).


4.1.5. ACL of Clients
4.1.5. クライアントのACL

In cases of dual-stack clients, AAAA queries typically take preference over A queries. If DNS64 is enabled for those clients, it will never get A records, even for IPv4-only servers.


As a consequence, in cases where there are IPv4-only servers, and those are located in the path before the NAT64 function, the clients will not be able to reach them. If DNSSEC is being used for all those flows, specific addresses or prefixes can be left out of the DNS64 synthesis by means of Access Control Lists (ACLs).


Once more, this will not work without a CLAT function (which is the case for all scenarios without 464XLAT).


4.1.6. Mapping Out IPv4 Addresses
4.1.6. IPv4アドレスのマッピング

If there are well-known specific IPv4 addresses or prefixes using DNSSEC, they can be mapped out of the DNS64 synthesis.


Even if this is not related to DNSSEC, this "mapping-out" feature is quite commonly used to ensure that addresses [RFC1918] (for example, used by LAN servers) are not synthesized to AAAA.


Once more, this will not work without a CLAT function (which is the case for all scenarios without 464XLAT).


4.2. DNS64 and Reverse Mapping
4.2. DNS64と逆マッピング

When a client device using DNS64 tries to reverse-map a synthesized IPv6 address, the name server responds with a CNAME record that points the domain name used to reverse-map the synthesized IPv6 address (the one under to the domain name corresponding to the embedded IPv4 address (under


This is the expected behavior, so no issues need to be considered regarding DNS reverse mapping.


4.3. Using 464XLAT with/without DNS64
4.3. DNS64あり/なしの464XLATの使用

In case the client device is IPv6 only (either because the stack or application is IPv6 only or because it is connected via an IPv6-only LAN) and the remote server is IPv4 only (either because the stack is IPv4 only or because it is connected via an IPv4-only LAN), only NAT64 combined with DNS64 will be able to provide access between both. Because DNS64 is then required, DNSSEC validation will only be possible if the recursive name server is validating the negative response from the authoritative name server, and the client is not performing validation.


Note that at this stage of the transition, it is not expected that applications, devices, or Operating Systems are IPv6 only. It will not be a sensible decision for a developer to work on that direction, unless it is clear that the deployment scenario fully supports it.


On the other hand, an end user or enterprise network may decide to run IPv6 only in the LANs. In case there is any chance for applications to be IPv6 only, the Operating System may be responsible for either doing a local address synthesis or setting up some kind of on-demand VPN (IPv4-in-IPv6), which needs to be supported by that network. This may become very common in enterprise networks, where "Unique IPv6 Prefix per Host" [RFC8273] is supported.


However, when the client device is dual stack and/or connected in a dual-stack LAN by means of a CLAT function (or has a built-in CLAT function), DNS64 is an option.


1. With DNS64: If DNS64 is used, most of the IPv4 traffic (except if using literal IPv4 addresses or non-IPv6-compliant APIs) will not use the CLAT and will instead use the IPv6 path, so only one translation will be done at the NAT64. This may break DNSSEC, unless measures as described in the previous sections are taken.

1. DNS64を使用する場合:DNS64を使用する場合、ほとんどのIPv4トラフィック(リテラルIPv4アドレスまたは非IPv6準拠のAPIを使用する場合を除く)はCLATを使用せず、代わりにIPv6パスを使用するため、 NAT64。これは、前のセクションで説明したような対策を講じない限り、DNSSECを破壊する可能性があります。

2. Without DNS64: If DNS64 is not used, all the IPv4 traffic will make use of the CLAT, so two translations are required (NAT46 at the CLAT and NAT64 at the PLAT), which adds some overhead in terms of the extra NAT46 translation. However, this avoids the AAAA synthesis and consequently will never break DNSSEC.

2. DNS64がない場合:DNS64が使用されない場合、すべてのIPv4トラフィックがCLATを使用するため、2つの変換が必要です(CLATでのNAT46とPLATでのNAT64)。これにより、NAT46変換の追加という点でいくつかのオーバーヘッドが追加されます。ただし、これによりAAAA合成が回避されるため、DNSSECが壊れることはありません。

Note that the extra translation, when DNS64 is not used, takes place at the CLAT, which means no extra overhead for the operator. However, it adds potential extra delays to establish the connections and has no perceptible impact for a CE in a broadband network, but it may have some impact on a battery-powered device. The cost for a battery-powered device is possibly comparable to the cost when the device is doing a local address synthesis (see Section 7.1 of [RFC8305]).


4.4. Foreign DNS
4.4. 外部DNS

Clients, devices, or applications in a service-provider network may use DNS servers from other networks. This may be the case if individual applications use their own DNS server, the Operating System itself or even the CE, or combinations of the above.


Those "foreign" DNS servers may not support DNS64; as a consequence, those scenarios that require a DNS64 may not work. However, if a CLAT function is available, the considerations in Section 4.3 will apply.


If the foreign DNS supports the DNS64 function, incorrect configuration parameters may be provided that, for example, cause WKP or NSP to become unmatched or result in a case such as the one described in Section 3.2.3.


Having a CLAT function, even if using foreign DNS without a DNS64 function, ensures that everything will work, so the CLAT must be considered to be an advantage despite user configuration errors. As a result, all the traffic will use a double translation (NAT46 at the CLAT and NAT64 at the operator network), unless there is support for EAM (Section 4.9).


An exception is the case where there is a CLAT function at the CE that is not able to obtain the correct configuration parameters (again, causing WKP or NSP to become unmatched).


However, it needs to be emphasized that if there is no CLAT function (which is the case for all scenarios without 464XLAT), an external DNS without DNS64 support will disallow any access to IPv4-only destination networks and will not guarantee the correct DNSSEC validation, so it will behave as in Section 3.2.1.


In summary, the consequences of using foreign DNS depends on each specific case. However, in general, if a CLAT function is present, most of the time there will not be any issues. In the other cases, the access to IPv6-enabled services is still guaranteed for IPv6-enabled hosts, but it is not guaranteed for IPv4-only hosts nor is the access to IPv4-only services for any hosts in the network.


The causes of "foreign DNS" could be classified in three main categories, as depicted in the following subsections.


4.4.1. Manual Configuration of DNS
4.4.1. DNSの手動構成

It is becoming increasingly common that end users, or even devices or applications, configure alternative DNS in their Operating Systems and sometimes in CEs.


4.4.2. DNS Privacy/Encryption Mechanisms
4.4.2. DNSプライバシー/暗号化メカニズム

Clients or applications may use mechanisms for DNS privacy/ encryption, such as DNS over TLS (DoT) [RFC7858], DNS over DTLS [RFC8094], DNS queries over HTTPS (DoH) [RFC8484], or DNS over QUIC (DoQ) [QUIC-CONNECTIONS].

クライアントまたはアプリケーションは、DNSプライバシー/暗号化のメカニズムを使用できます。たとえば、DNS over TLS(DoT)[RFC7858]、DNS over DTLS [RFC8094]、DNS over HTTPS(DoH)[RFC8484]、DNS over QUIC(DoQ)[ QUIC-CONNECTIONS]。

Currently, those DNS privacy/encryption options are typically provided by the applications, not the Operating System vendors. At the time this document was written, the DoT and DoH standards have declared DNS64 (and consequently NAT64) out of their scope, so an application using them may break NAT64, unless a correctly configured CLAT function is used.


4.4.3. Split DNS and VPNs
4.4.3. DNSとVPNを分割する

When networks or hosts use "split-DNS" (also called Split Horizon, DNS views, or private DNS), the successful use of DNS64 is not guaranteed. This case is analyzed in Section 4 of [RFC6950].


A similar situation may happen with VPNs that force all the DNS queries through the VPN and ignore the operator DNS64 function.


4.5. Well-Known Prefix (WKP) vs. Network-Specific Prefix (NSP)
4.5. 既知のプレフィックス(WKP)とネットワーク固有のプレフィックス(NSP)

Section 3 of "IPv6 Addressing of IPv4/IPv6 Translator" [RFC6052] discusses some considerations that are useful to an operator when deciding if a WKP or an NSP should be used.

「IPv4 / IPv6トランスレーターのIPv6アドレッシング」[RFC6052]のセクション3では、WKPとNSPのどちらを使用するかを決定するときにオペレーターに役立ついくつかの考慮事項について説明します。

Considering that discussion and other issues, we can summarize the possible decision points to as follows:


a. The WKP MUST NOT be used to represent non-global IPv4 addresses. If this is required because the network to be translated uses non-global addresses, then an NSP is required.

a. WKPは、非グローバルIPv4アドレスを表すために使用してはなりません(MUST NOT)。変換されるネットワークが非グローバルアドレスを使用するためにこれが必要な場合は、NSPが必要です。

b. The WKP MAY appear in interdomain routing tables, if the operator provides a NAT64 function to peers. However, in this case, special considerations related to BGP filtering are required, and IPv4-embedded IPv6 prefixes longer than the WKP MUST NOT be advertised (or accepted) in BGP. An NSP may be a more appropriate option in those cases.

b. オペレーターがピアにNAT64機能を提供する場合、WKPはドメイン間ルーティングテーブルに表示される場合があります。ただし、この場合、BGPフィルタリングに関連する特別な考慮事項が必要であり、WKPより長いIPv4埋め込みIPv6プレフィックスは、BGPでアドバタイズ(または受け入れ)してはなりません(MUST NOT)。そのような場合は、NSPがより適切なオプションになる場合があります。

c. If several NAT64s use the same prefix, packets from the same flow may be routed to a different NAT64 in case of routing changes. This can be avoided by either using different prefixes for each NAT64 function or ensuring that all the NAT64s coordinate their state. Using an NSP could simplify that.

c. 複数のNAT64が同じプレフィックスを使用する場合、ルーティングが変更された場合、同じフローからのパケットが別のNAT64にルーティングされる可能性があります。これは、NAT64関数ごとに異なるプレフィックスを使用するか、すべてのNAT64がその状態を調整するようにすることで回避できます。 NSPを使用すると、それを簡素化できます。

d. If DNS64 is required and users, devices, Operating Systems, or applications may change their DNS configuration and deliberately choose an alternative DNS64 function, the alternative DNS64 will most likely use the WKP by default. In that case, if an NSP is used by the NAT64 function, clients will not be able to use the operator NAT64 function, which will break connectivity to IPv4-only destinations.

d. DNS64が必要で、ユーザー、デバイス、オペレーティングシステム、またはアプリケーションがDNS構成を変更し、故意に代替DNS64関数を選択する場合、代替DNS64はデフォルトでWKPを使用する可能性が最も高くなります。その場合、NSPがNAT64機能で使用されると、クライアントはオペレーターのNAT64機能を使用できなくなり、IPv4のみの宛先への接続が切断されます。

4.6. IPv4 Literals and Non-IPv6-Compliant APIs
4.6. IPv4リテラルと非IPv6準拠のAPI

A host or application using literal IPv4 addresses or older APIs, which aren't IPv6 compliant, behind a network with IPv6-only access will not work unless any of the following alternatives are provided:


* CLAT (or an equivalent function).

* CLAT(または同等の関数)。

* Happy Eyeballs v2 (Section 7.1 of [RFC8305]).

* Happy Eyeballs v2([RFC8305]のセクション7.1)。

* Bump-in-the-Host [RFC6535] with a DNS64 function.

* DNS64機能を備えたBump-in-the-Host [RFC6535]。

Those alternatives will solve the problem for an end host. However, if the end host is providing "tethering" or an equivalent service to other hosts, that needs to be considered as well. In other words, in a cellular network, these alternatives resolve the issue for the UE itself, but this may not be the case for hosts connected via the tethering.


Otherwise, the support of 464XLAT is the only valid and complete approach to resolve this issue.


4.7. IPv4-Only Hosts or Applications
4.7. IPv4のみのホストまたはアプリケーション

IPv4-only hosts or an application behind a network with IPv6-only access will not work unless a CLAT function is present.


464XLAT is the only valid approach to resolve this issue.


4.8. CLAT Translation Considerations
4.8. CLAT変換の考慮事項

As described in "IPv6 Prefix Handling" (see Section 6.3 of [RFC6877]), if the CLAT function can be configured with a dedicated /64 prefix for the NAT46 translation, then it will be possible to do a more efficient stateless translation.

「IPv6プレフィックスの処理」([RFC6877]のセクション6.3を参照)で説明されているように、NAT46変換に専用の/ 64プレフィックスを使用してCLAT機能を構成できる場合は、より効率的なステートレス変換を実行できます。

Otherwise, if this dedicated prefix is not available, the CLAT function will need to do a stateful translation, for example, perform stateful NAT44 for all the IPv4 LAN packets so they appear as coming from a single IPv4 address; in turn, the CLAT function will perform a stateless translation to a single IPv6 address.

それ以外の場合、この専用プレフィックスが使用できない場合、CLAT関数はステートフル変換を行う必要があります。たとえば、すべてのIPv4 LANパケットに対してステートフルNAT44を実行して、単一のIPv4アドレスから送信されたように見せます。次に、CLAT関数は、単一のIPv6アドレスへのステートレス変換を実行します。

A possible setup, in order to maximize the CLAT performance, is to configure the dedicated translation prefix. This can be easily achieved automatically, if the broadband CE or end-user device is able to obtain a shorter prefix by means of DHCPv6-PD [RFC8415] or other alternatives. The CE can then use a specific /64 for the translation. This is also possible when broadband is provided by a cellular access.

CLATのパフォーマンスを最大化するために可能な設定は、専用の変換プレフィックスを構成することです。これは、ブロードバンドCEまたはエンドユーザーデバイスがDHCPv6-PD [RFC8415]または他の代替手段によって短いプレフィックスを取得できる場合、自動的に簡単に実現できます。その後、CEは特定の/ 64を変換に使用できます。これは、セルラーアクセスによってブロードバンドが提供される場合にも可能です。

The above recommendation is often not possible for cellular networks, when connecting smartphones (as UEs): generally they don't use DHCPv6-PD [RFC8415]. Instead, a single /64 is provided for each Packet Data Protocol (PDP) context, and prefix sharing [RFC6877] is used. In this case, the UEs typically have a build-in CLAT function that is performing a stateful NAT44 translation before the stateless NAT46.

上記の推奨事項は、スマートフォンを(UEとして)接続する場合、セルラーネットワークでは多くの場合不可能です。通常、それらはDHCPv6-PD [RFC8415]を使用しません。代わりに、単一の/ 64が各パケットデータプロトコル(PDP)コンテキストに提供され、プレフィックス共有[RFC6877]が使用されます。この場合、UEには通常、ステートレスNAT46の前にステートフルNAT44変換を実行するビルトインCLAT機能があります。

4.9. EAM Considerations
4.9. POMに関する考慮事項

"Explicit Address Mappings for Stateless IP/ICMP Translation" [RFC7757] provides a way to configure explicit mappings between IPv4 and IPv6 prefixes of any length. When this is used, for example, in a CLAT function, it may provide a simple mechanism in order to avoid traffic flows between IPv4-only nodes or applications and dual-stack destinations to be translated twice (NAT46 and NAT64), by creating mapping entries with the Global Unicast Address (GUA) of the IPv6-reachable destination. This optimization of NAT64 usage is very useful in many scenarios, including Content Delivery Networks (CDNs) and caches, as described in [OPT-464XLAT].

「ステートレスIP / ICMP変換の明示的なアドレスマッピング」[RFC7757]は、任意の長さのIPv4とIPv6プレフィックス間の明示的なマッピングを構成する方法を提供します。これをたとえばCLAT関数で使用すると、マッピングを作成することにより、IPv4のみのノードまたはアプリケーションとデュアルスタック宛先の間のトラフィックフローが2回変換されるのを防ぐために、シンプルなメカニズムを提供できます(NAT46とNAT64)。 IPv6到達可能宛先のグローバルユニキャストアドレス(GUA)を持つエントリ。このNAT64の使用の最適化は、[OPT-464XLAT]で説明されているように、コンテンツ配信ネットワーク(CDN)やキャッシュなど、多くのシナリオで非常に役立ちます。

In addition, it may also provide a way for IPv4-only nodes or applications to communicate with IPv6-only destinations.


4.10. Incoming Connections
4.10. 着信接続

The use of NAT64, in principle, disallows IPv4 incoming connections, which may still be needed for IPv4-only peer-to-peer applications. However, there are several alternatives that resolve this issue:


a. Session Traversal Utilities for NAT (STUN) [RFC5389], Traversal Using Relays around NAT (TURN) [RFC5766], and Interactive Connectivity Establishment (ICE) [RFC8445] are commonly used by peer-to-peer applications in order to allow incoming connections with IPv4 NAT. In the case of NAT64, they work as well.

a. NATのセッショントラバーサルユーティリティ(STUN)[RFC5389]、NAT周辺のリレーを使用したトラバーサル(TURN)[RFC5766]、およびインタラクティブ接続確立(ICE)[RFC8445]は、着信接続を許可するためにピアツーピアアプリケーションで一般的に使用されますIPv4 NAT。 NAT64の場合も機能します。

b. The Port Control Protocol (PCP) [RFC6887] allows a host to control how incoming IPv4 and IPv6 packets are translated and forwarded. A NAT64 may implement PCP to allow this service.

b. ポート制御プロトコル(PCP)[RFC6887]を使用すると、ホストは着信IPv4およびIPv6パケットの変換および転送方法を制御できます。 NAT64はPCPを実装してこのサービスを許可する場合があります。

c. EAM [RFC7757] may also be used in order to configure explicit mappings for customers that require them. This is used, for example, by Stateless IP/ICMP Translation for IPv6 Data Center Environments (SIIT-DC) [RFC7755] and SIIT-DC Dual Translation Mode (SIIT-DC-DTM) [RFC7756].

c. EAM [RFC7757]は、それらを必要とする顧客の明示的なマッピングを構成するために使用することもできます。これは、たとえば、IPv6データセンター環境用のステートレスIP / ICMP変換(SIIT-DC)[RFC7755]およびSIIT-DCデュアル変換モード(SIIT-DC-DTM)[RFC7756]によって使用されます。

5. Summary of Deployment Recommendations for NAT64/464XLAT
5. NAT64 / 464XLATの展開に関する推奨事項の概要

It has been demonstrated that NAT64/464XLAT is a valid choice in several scenarios (IPv6-IPv4 and IPv4-IPv6-IPv4), being the predominant mechanism in the majority of the cellular networks, which account for hundreds of millions of users [ISOC]. NAT64/464XLAT offer different choices of deployment, depending on each network case, needs, and requirements. Despite that, this document is not an explicit recommendation for using this choice versus other IPv4aaS transition mechanisms. Instead, this document is a guide that facilitates evaluating a possible implementation of NAT64/464XLAT and key decision points about specific design considerations for its deployment.

NAT64 / 464XLATはいくつかのシナリオ(IPv6-IPv4およびIPv4-IPv6-IPv4)で有効な選択肢であり、数億人のユーザーを占める大多数のセルラーネットワークの主要なメカニズムであることが示されています[ISOC] 。 NAT64 / 464XLATは、ネットワークの各ケース、ニーズ、および要件に応じて、さまざまな展開の選択肢を提供します。それにもかかわらず、このドキュメントは、この選択を他のIPv4aaS移行メカニズムと比較して使用するための明示的な推奨事項ではありません。代わりに、このドキュメントは、NAT64 / 464XLATの可能な実装と、その展開に関する特定の設計上の考慮事項に関する重要な決定ポイントの評価を容易にするガイドです。

Depending on the specific requirements of each deployment case, DNS64 may be a required function, while in other cases, the adverse effects may be counterproductive. Similarly, in some cases, a NAT64 function, together with a DNS64 function, may be a valid solution when there is a certainty that IPv4-only hosts or applications do not need to be supported (see Sections 4.6 and 4.7). However, in other cases (i.e., IPv4-only devices or applications that need to be supported), the limitations of NAT64/DNS64 may indicate that the operator needs to look into 464XLAT as a more complete solution.

各展開ケースの特定の要件に応じて、DNS64が必要な機能になる場合がありますが、他の場合では、悪影響が逆効果になる場合があります。同様に、場合によっては、IPv4のみのホストまたはアプリケーションをサポートする必要がないことが確実である場合に、DNS64関数と一緒にNAT64関数が有効なソリューションになることがあります(セクション4.6および4.7を参照)。ただし、他の場合(つまり、サポートする必要があるIPv4専用のデバイスまたはアプリケーション)では、NAT64 / DNS64の制限により、オペレーターがより完全なソリューションとして464XLATを調査する必要があることが示される場合があります。

For broadband-managed networks (where the CE is provided or suggested/supported by the operator), in order to fully support the actual user's needs (i.e., IPv4-only devices and applications and the usage of IPv4 literals and non-IPv6-compliant APIs), the 464XLAT scenario should be considered. In that case, it must support a CLAT function.

ブロードバンド管理ネットワーク(CEが提供されるか、オペレーターによって提案/サポートされる)の場合、実際のユーザーのニーズ(つまり、IPv4のみのデバイスとアプリケーション、およびIPv4リテラルと非IPv6準拠の使用を完全にサポートするため) API)、464XLATシナリオを検討する必要があります。その場合、CLAT関数をサポートする必要があります。

If the operator provides DNS services, they may support a DNS64 function to avoid, as much as possible, breaking DNSSEC. This will also increase performance, by reducing the double translation for all the IPv4 traffic. In this case, if the DNS service is offering DNSSEC validation, then it must be in such a way that it is aware of the DNS64. This is considered the simpler and safer approach, and it may be combined with other recommendations described in this document:


* DNS infrastructure MUST be aware of DNS64 (Section 4.1.2).

* DNSインフラストラクチャはDNS64を認識している必要があります(セクション4.1.2)。

* Devices running CLAT SHOULD follow the indications in "Stub Validator" (see Section 4.1.3). However, this may be out of the control of the operator.

* CLATを実行するデバイスは、「スタブバリデーター」の指示に従う必要があります(セクション4.1.3を参照)。ただし、これはオペレータの制御の範囲外である可能性があります。

* CEs SHOULD include a DNS proxy and validator (Section 4.1.4).

* CEには、DNSプロキシとバリデーターを含める必要があります(セクション4.1.4)。

* "ACL of Clients" (see Section 4.1.5) and "Mapping Out IPv4 Addresses" (see Section 4.1.6) MAY be considered by operators, depending on their own infrastructure.

* 「クライアントのACL」(セクション4.1.5を参照)および「IPv4アドレスのマッピング」(セクション4.1.6を参照)は、独自のインフラストラクチャに応じて、オペレータによって検討される場合があります。

This "increased performance" approach has the disadvantage of potentially breaking DNSSEC for a small percentage of validating end hosts versus the small impact of a double translation taking place in the CE. If CE performance is not an issue, which is the most frequent case, then a much safer approach is to not use DNS64 at all, and consequently, ensure that all the IPv4 traffic is translated at the CLAT (Section 4.3).


If DNS64 is not used, at least one of the alternatives described in Section 4.1.1 must be followed in order to learn the NAT64 prefix.


The operator needs to consider that if the DNS configuration is modified (see Sections 4.4, 4.4.2, and 4.4.3), which most likely cannot be avoided, a foreign non-DNS64 could be used instead of configuring a DNS64. In a scenario with only a NAT64 function, an IPv4-only remote host will no longer be accessible. Instead, it will continue to work in the case of 464XLAT.

オペレーターは、回避できない可能性が最も高いDNS構成が変更された場合(セクション4.4、4.4.2、および4.4.3を参照)、DNS64を構成する代わりに外部の非DNS64を使用できることを考慮する必要があります。 NAT64機能のみのシナリオでは、IPv4のみのリモートホストにアクセスできなくなります。代わりに、464XLATの場合は引き続き機能します。

Similar considerations need to be made regarding the usage of a NAT64 WKP vs. NSP (Section 4.5), as they must match the configuration of DNS64. When using foreign DNS, they may not match. If there is a CLAT and the configured foreign DNS is not a DNS64, the network will keep working only if other means of learning the NAT64 prefix are available.

NAT64 WKPとNSP(セクション4.5)の使用については、DNS64の構成と一致する必要があるため、同様の考慮事項を行う必要があります。外部DNSを使用する場合、それらは一致しない場合があります。 CLATがあり、構成された外部DNSがDNS64でない場合、ネットワークは、NAT64プレフィックスを学習する他の手段が利用可能な場合にのみ機能し続けます。

For broadband networks, as described in Section 4.8, the CEs supporting a CLAT function SHOULD support DHCPv6-PD [RFC8415] or alternative means for configuring a shorter prefix. The CE SHOULD internally reserve one /64 for the stateless NAT46 translation. The operator must ensure that the customers are allocated prefixes shorter than /64 in order to support this optimization. One way or another, this is not impacting the performance of the operator network.

ブロードバンドネットワークの場合、セクション4.8で説明されているように、CLAT機能をサポートするCEは、DHCPv6-PD [RFC8415]または短いプレフィックスを構成するための代替手段をサポートする必要があります(SHOULD)。 CEは内部でステートレスNAT46変換用に1/64を予約する必要があります(SHOULD)。オペレーターは、この最適化をサポートするために、顧客に/ 64より短いプレフィックスが割り当てられていることを確認する必要があります。いずれにせよ、これは事業者ネットワークのパフォーマンスに影響を与えていません。

Operators may follow "Deployment Considerations" (Section 7 of [RFC6877]) for suggestions on how to take advantage of traffic-engineering requirements.


For cellular networks, the considerations regarding DNSSEC may appear to be out of scope because UEs' Operating Systems commonly don't support DNSSEC. However, applications running on them may, or it may be an Operating System "built-in" support in the future. Moreover, if those devices offer tethering, other client devices behind the UE may be doing the validation; hence, proper DNSSEC support by the operator network is relevant.


Furthermore, cellular networks supporting 464XLAT [RFC6877] and "Discovery of the IPv6 Prefix Used for IPv6 Address Synthesis" [RFC7050] allow a progressive IPv6 deployment, with a single Access Point Name (APN) supporting all types of PDP context (IPv4, IPv6, and IPv4v6). This approach allows the network to automatically serve every possible combination of UEs.

さらに、464XLAT [RFC6877]および「IPv6アドレス合成に使用されるIPv6プレフィックスの検出」[RFC7050]をサポートするセルラーネットワークでは、すべてのタイプのPDPコンテキスト(IPv4、IPv6 、およびIPv4v6)。このアプローチにより、ネットワークはUEのあらゆる可能な組み合わせに自動的に対応できます。

If the operator chooses to provide validation for the DNS64 prefix discovery, it must follow the advice from "Validation of Discovered Pref64::/n" (see Section 3.1 of [RFC7050]).

オペレーターがDNS64プレフィックス検出の検証を提供することを選択した場合、「検出されたPref64 :: / nの検証」からのアドバイスに従う必要があります([RFC7050]のセクション3.1を参照)。

One last consideration is that many networks may have a mix of different complex scenarios at the same time; for example, customers that require 464XLAT and those that don't, customers that require DNS64 and those that don't, etc. In general, the different issues and the approaches described in this document can be implemented at the same time for different customers or parts of the network. That mix of approaches doesn't present any problem or incompatibility; they work well together as a matter of appropriate and differentiated provisioning. In fact, the NAT64/464XLAT approach facilitates an operator offering both cellular and broadband services to have a single IPv4aaS for both networks while differentiating the deployment key decisions to optimize each case. It's even possible to use hybrid CEs that have a main broadband access link and a backup via the cellular network.

最後に考慮しなければならないのは、多くのネットワークで同時に異なる複雑なシナリオが混在する可能性があることです。たとえば、464XLATを必要とするお客様と必要としないお客様、DNS64を必要とするお客様と必要としないお客様など。一般に、このドキュメントで説明されているさまざまな問題とアプローチは、さまざまなお客様に同時に実装できますまたはネットワークの一部。このようなアプローチを組み合わせても、問題や非互換性はありません。これらは、適切で差別化されたプロビジョニングの問題として、連携して機能します。実際、NAT64 / 464XLATアプローチは、セルラーサービスとブロードバンドサービスの両方を提供するオペレーターが、両方のネットワークに単一のIPv4aaSを提供すると同時に、それぞれのケースを最適化するための展開の重要な決定を差別化します。メインブロードバンドアクセスリンクとセルラーネットワーク経由のバックアップを備えたハイブリッドCEを使用することも可能です。

In an ideal world, we could safely use DNS64 if the approach proposed in [DNS-DNSSEC] were followed, avoiding the cases where DNSSEC may be broken. However, this will not solve the issues related to DNS privacy and split DNS.


The only 100% safe solution that also resolves all the issues is, in addition to having a CLAT function, not using a DNS64 but instead making sure that the hosts have a built-in address synthesis feature. Operators could manage to provide CEs with the CLAT function; however, the built-in address synthesis feature is out of their control. If the synthesis is provided by either the Operating System (via its DNS resolver API) or the application (via its own DNS resolver) in such way that the prefix used for the NAT64 function is reachable for the host, the problem goes away.


Whenever feasible, using EAM [RFC7757] as indicated in Section 4.9 provides a very relevant optimization, avoiding double translations.

可能な場合はいつでも、セクション4.9で示されているようにEAM [RFC7757]を使用することで、非常に適切な最適化が提供され、二重変換が回避されます。

Applications that require incoming connections typically provide a means for that already. However, PCP and EAM, as indicated in Section 4.10, are valid alternatives, even for creating explicit mappings for customers that require them.


6. Deployment of 464XLAT/NAT64 in Enterprise Networks
6. エンタープライズネットワークでの464XLAT / NAT64の導入

The recommendations in this document can also be used in enterprise networks, campuses, and other similar scenarios (including managed end-user networks).


This includes scenarios where the NAT64 function (and DNS64 function, if available) are under the control of that network (or can be configured manually according to that network's specific requirements), and there is a need to provide IPv6-only access to any part of that network, or it is IPv6 only connected to third-party networks.


An example is the IETF meeting network itself, where both NAT64 and DNS64 functions are provided, presenting in this case the same issues as per Section 3.1.1. If there is a CLAT function in the IETF network, then there is no need to use DNS64, and it falls under the considerations of Section 3.1.3. Both scenarios have been tested and verified already in the IETF network.

例として、IETFミーティングネットワーク自体があり、NAT64とDNS64の両方の機能が提供されています。この場合、セクション3.1.1と同じ問題が発生します。 IETFネットワークにCLAT機能がある場合、DNS64を使用する必要はなく、セクション3.1.3の考慮事項に該当します。どちらのシナリオもIETFネットワークでテストおよび検証されています。

The following figures represent a few of the possible scenarios.


Figure 13 provides an example of an IPv6-only enterprise network connected with a dual stack to the Internet using local NAT64 and DNS64 functions.


          |       Enterprise Network         |
          | +----------+        +----------+ |       +----------+
          | |   IPv6-  |        |  NAT64   | |       |   IPv4   |
          | |   only   +--------+    +     | +-------+     +    |
          | |   LANs   |        |  DNS64   | |       |   IPv6   |
          | +----------+        +----------+ |       +----------+

Figure 13: IPv6-Only Enterprise with NAT64 and DNS64


Figure 14 provides an example of a DS enterprise network connected with DS to the Internet using a CLAT function, without a DNS64 function.


          |       Enterprise Network         |
          | +----------+        +----------+ |       +----------+
          | |   IPv6   |        |          | |       |   IPv4   |
          | |     +    +--------+  NAT64   | +-------+     +    |
          | |   CLAT   |        |          | |       |   IPv6   |
          | +----------+        +----------+ |       +----------+

Figure 14: DS Enterprise with CLAT, DS Internet, without DNS64


Finally, Figure 15 provides an example of an IPv6-only provider with a NAT64 function, and a DS enterprise network by means of their own CLAT function, without a DNS64 function.


         |       Enterprise Network         |
         | +----------+        +----------+ |        +----------+
         | |   IPv6   |        |          | |  IPv6  |          |
         | |     +    +--------+   CLAT   | +--------+   NAT64  |
         | |   IPv4   |        |          | |  only  |          |
         | +----------+        +----------+ |        +----------+

Figure 15: DS Enterprise with CLAT and IPv6-Only Access, without DNS64


7. Security Considerations
7. セキュリティに関する考慮事項

This document does not have new specific security considerations beyond those already reported by each of the documents cited. For example, DNS64 [RFC6147] already describes the DNSSEC issues.

このドキュメントには、引用された各ドキュメントによってすでに報告されているものを超える、特定のセキュリティに関する新しい考慮事項はありません。たとえば、DNS64 [RFC6147]はすでにDNSSECの問題について説明しています。

As already described in Section 4.4, note that there may be undesirable interactions, especially if using VPNs or DNS privacy, which may impact the correct performance of DNS64/NAT64.

セクション4.4で既に説明したように、特にVPNまたはDNSプライバシーを使用している場合、望ましくない相互作用があり、DNS64 / NAT64の正しいパフォーマンスに影響を与える可能性があることに注意してください。

Note that the use of a DNS64 function has privacy considerations that are equivalent to regular DNS, and they are located in either the service provider or an external service provider.


8. IANA Considerations
8. IANAに関する考慮事項

This document has no IANA actions.


9. References
9. 参考文献
9.1. Normative References
9.1. 引用文献

[RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G. J., and E. Lear, "Address Allocation for Private Internets", BCP 5, RFC 1918, DOI 10.17487/RFC1918, February 1996, <>.

[RFC1918] Rekhter、Y.、Moskowitz、B.、Karrenberg、D.、de Groot、GJ、およびE. Lear、「プライベートインターネットのアドレス割り当て」、BCP 5、RFC 1918、DOI 10.17487 / RFC1918、1996年2月、 <>。

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <>.

[RFC2119] Bradner、S。、「要件レベルを示すためにRFCで使用するキーワード」、BCP 14、RFC 2119、DOI 10.17487 / RFC2119、1997年3月、< rfc2119>。

[RFC5389] Rosenberg, J., Mahy, R., Matthews, P., and D. Wing, "Session Traversal Utilities for NAT (STUN)", RFC 5389, DOI 10.17487/RFC5389, October 2008, <>.

[RFC5389] Rosenberg、J.、Mahy、R.、Matthews、P。、およびD. Wing、「NAT用セッショントラバーサルユーティリティ(STUN)」、RFC 5389、DOI 10.17487 / RFC5389、2008年10月、<https://>。

[RFC5625] Bellis, R., "DNS Proxy Implementation Guidelines", BCP 152, RFC 5625, DOI 10.17487/RFC5625, August 2009, <>.

[RFC5625] Bellis、R。、「DNSプロキシ実装ガイドライン」、BCP 152、RFC 5625、DOI 10.17487 / RFC5625、2009年8月、<>。

[RFC5766] Mahy, R., Matthews, P., and J. Rosenberg, "Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN)", RFC 5766, DOI 10.17487/RFC5766, April 2010, <>.

[RFC5766] Mahy、R.、Matthews、P。、およびJ. Rosenberg、「NATのリレーを使用したトラバーサル(TURN):NATのセッショントラバーサルユーティリティへのリレー拡張(STUN)」、RFC 5766、DOI 10.17487 / RFC5766、4月2010、<>。

[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X. Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052, DOI 10.17487/RFC6052, October 2010, <>.

[RFC6052] Bao、C.、Huitema、C.、Bagnulo、M.、Boucadair、M。、およびX. Li、「IPv4 / IPv6トランスレータのIPv6アドレッシング」、RFC 6052、DOI 10.17487 / RFC6052、2010年10月、<>。

[RFC6144] Baker, F., Li, X., Bao, C., and K. Yin, "Framework for IPv4/IPv6 Translation", RFC 6144, DOI 10.17487/RFC6144, April 2011, <>.

[RFC6144] Baker、F.、Li、X.、Bao、C。、およびK. Yin、「IPv4 / IPv6変換のフレームワーク」、RFC 6144、DOI 10.17487 / RFC6144、2011年4月、<https:// www。>。

[RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers", RFC 6146, DOI 10.17487/RFC6146, April 2011, <>.

[RFC6146] Bagnulo、M.、Matthews、P。、およびI. van Beijnum、「ステートフルNAT64:IPv6クライアントからIPv4サーバーへのネットワークアドレスおよびプロトコル変換」、RFC 6146、DOI 10.17487 / RFC6146、2011年4月、<https: //>。

[RFC6147] Bagnulo, M., Sullivan, A., Matthews, P., and I. van Beijnum, "DNS64: DNS Extensions for Network Address Translation from IPv6 Clients to IPv4 Servers", RFC 6147, DOI 10.17487/RFC6147, April 2011, <>.

[RFC6147] Bagnulo、M.、Sullivan、A.、Matthews、P.、I。van Beijnum、「DNS64:DNS Extensions for Network Address Translation to IPv4 Servers to RFC」、RFC 6147、DOI 10.17487 / RFC6147、4月2011、<>。

[RFC6535] Huang, B., Deng, H., and T. Savolainen, "Dual-Stack Hosts Using "Bump-in-the-Host" (BIH)", RFC 6535, DOI 10.17487/RFC6535, February 2012, <>.

[RFC6535] Huang、B.、Deng、H。、およびT. Savolainen、「Bump-in-the-Host(BIH)を使用したデュアルスタックホスト」、RFC 6535、DOI 10.17487 / RFC6535、2012年2月、<>。

[RFC6877] Mawatari, M., Kawashima, M., and C. Byrne, "464XLAT: Combination of Stateful and Stateless Translation", RFC 6877, DOI 10.17487/RFC6877, April 2013, <>.

[RFC6877] Mawatari、M.、Kawashima、M。、およびC. Byrne、「464XLAT:Combination of Stateful and Stateless Translation」、RFC 6877、DOI 10.17487 / RFC6877、2013年4月、<https://www.rfc-editor .org / info / rfc6877>。

[RFC6887] Wing, D., Ed., Cheshire, S., Boucadair, M., Penno, R., and P. Selkirk, "Port Control Protocol (PCP)", RFC 6887, DOI 10.17487/RFC6887, April 2013, <>.

[RFC6887] Wing、D.、Ed。、Cheshire、S.、Boucadair、M.、Penno、R。、およびP. Selkirk、「Port Control Protocol(PCP)」、RFC 6887、DOI 10.17487 / RFC6887、2013年4月、<>。

[RFC7050] Savolainen, T., Korhonen, J., and D. Wing, "Discovery of the IPv6 Prefix Used for IPv6 Address Synthesis", RFC 7050, DOI 10.17487/RFC7050, November 2013, <>.

[RFC7050] Savolainen、T.、Korhonen、J。、およびD. Wing、「IPv6アドレス合成に使用されるIPv6プレフィックスの発見」、RFC 7050、DOI 10.17487 / RFC7050、2013年11月、<https://www.rfc>。

[RFC7225] Boucadair, M., "Discovering NAT64 IPv6 Prefixes Using the Port Control Protocol (PCP)", RFC 7225, DOI 10.17487/RFC7225, May 2014, <>.

[RFC7225] Boucadair、M。、「Discovering NAT64 IPv6 Prefixes Using the Port Control Protocol(PCP)」、RFC 7225、DOI 10.17487 / RFC7225、2014年5月、< >。

[RFC7757] Anderson, T. and A. Leiva Popper, "Explicit Address Mappings for Stateless IP/ICMP Translation", RFC 7757, DOI 10.17487/RFC7757, February 2016, <>.

[RFC7757]アンダーソン、T。、およびA.リーバポッパー、「ステートレスIP / ICMP変換の明示的なアドレスマッピング」、RFC 7757、DOI 10.17487 / RFC7757、2016年2月、< / rfc7757>。

[RFC7915] Bao, C., Li, X., Baker, F., Anderson, T., and F. Gont, "IP/ICMP Translation Algorithm", RFC 7915, DOI 10.17487/RFC7915, June 2016, <>.

[RFC7915] Bao、C.、Li、X.、Baker、F.、Anderson、T。、およびF. Gont、「IP / ICMP変換アルゴリズム」、RFC 7915、DOI 10.17487 / RFC7915、2016年6月、<https: //>。

[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <>.

[RFC8174] Leiba、B。、「RFC 2119キーワードの大文字と小文字のあいまいさ」、BCP 14、RFC 8174、DOI 10.17487 / RFC8174、2017年5月、< rfc8174>。

[RFC8273] Brzozowski, J. and G. Van de Velde, "Unique IPv6 Prefix per Host", RFC 8273, DOI 10.17487/RFC8273, December 2017, <>.

[RFC8273] Brzozowski、J。およびG. Van de Velde、「Unique IPv6 Prefix per Host」、RFC 8273、DOI 10.17487 / RFC8273、2017年12月、<> 。

[RFC8305] Schinazi, D. and T. Pauly, "Happy Eyeballs Version 2: Better Connectivity Using Concurrency", RFC 8305, DOI 10.17487/RFC8305, December 2017, <>.

[RFC8305] Schinazi、D。およびT. Pauly、「Happy Eyeballs Version 2:Better Connectivity Using Concurrency」、RFC 8305、DOI 10.17487 / RFC8305、2017年12月、< rfc8305>。

[RFC8375] Pfister, P. and T. Lemon, "Special-Use Domain ''", RFC 8375, DOI 10.17487/RFC8375, May 2018, <>.

[RFC8375] Pfister、P。およびT. Lemon、「Special-Use Domain '。'」、RFC 8375、DOI 10.17487 / RFC8375、2018年5月、< / rfc8375>。

[RFC8415] Mrugalski, T., Siodelski, M., Volz, B., Yourtchenko, A., Richardson, M., Jiang, S., Lemon, T., and T. Winters, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 8415, DOI 10.17487/RFC8415, November 2018, <>.

[RFC8415] Mrugalski、T.、Siodelski、M.、Volz、B.、Yourtchenko、A.、Richardson、M.、Jiang、S.、Lemon、T。、およびT. Winters、「IPv6の動的ホスト構成プロトコル(DHCPv6)」、RFC 8415、DOI 10.17487 / RFC8415、2018年11月、<>。

[RFC8445] Keranen, A., Holmberg, C., and J. Rosenberg, "Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal", RFC 8445, DOI 10.17487/RFC8445, July 2018, <>.

[RFC8445] Keranen、A.、Holmberg、C。、およびJ. Rosenberg、「Interactive Connectivity Establishment(ICE):A Protocol for Network Address Translator(NAT)Traversal」、RFC 8445、DOI 10.17487 / RFC8445、2018年7月、<>。

[RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS (DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018, <>.

[RFC8484] Hoffman、P。およびP. McManus、「HTTPS(DoH)を介したDNSクエリ」、RFC 8484、DOI 10.17487 / RFC8484、2018年10月、<> 。

9.2. Informative References
9.2. 参考引用

[About-DNS64] Linkova, J., "Let's talk about IPv6 DNS64 & DNSSEC", June 2016, <>.

[About-DNS64] Linkova、J。、「Let's talk about IPv6 DNS64&DNSSEC」、2016年6月、< >。

[ARCEP] ARCEP, "Service client des operateurs : les mesures de qualite de service", April 2018, < cartes-et-donnees/nos-publications-chiffrees/service-client-des-operateurs-mesures-de-la-qualite-de-service/ service-client-des-operateurs-les-mesures-de-qualite-de-service.html>.

[ARCEP] ARCEP、「オペレーターカスタマーサービス:サービス品質の測定」、2018年4月、< cartes-et-dates / nos-publications-figures / service-client-des -operators-measures-of-the-quality-of-service / customer-service-of-operators-measures-of-quality-of-service.html>。

[DHCPv6-OPTIONS] Li, L., Cui, Y., Liu, C., Wu, J., Baker, F., and J. Palet, "DHCPv6 Options for Discovery NAT64 Prefixes", Work in Progress, Internet-Draft, draft-li-intarea-nat64-prefix-dhcp-option-02, 20 April 2019, < prefix-dhcp-option-02>.

[DHCPv6-OPTIONS] Li、L.、Cui、Y.、Liu、C.、Wu、J.、Baker、F.、J。Palet、「ディスカバリNAT64プレフィックスのDHCPv6オプション」、作業中、インターネット- Draft、draft-li-intarea-nat64-prefix-dhcp-option-02、2019年4月20日、< prefix-dhcp-option-02 >。

[DNS-DNSSEC] Byrne, C. and J. Palet, "IPv6-Ready DNS/DNSSSEC Infrastructure", Work in Progress, Internet-Draft, draft-bp-v6ops-ipv6-ready-dns-dnssec-00, 10 October 2018, <>.

[DNS-DNSSEC] Byrne、C。およびJ. Palet、「IPv6-Ready DNS / DNSSSEC Infrastructure」、Work in Progress、Internet-Draft、draft-bp-v6ops-ipv6-ready-dns-dnssec-00、10月10日2018、<>。

[DNS-RPZ] Vixie, P. and V. Schryver, "DNS Response Policy Zones (RPZ)", Work in Progress, Internet-Draft, draft-vixie-dnsop-dns-rpz-00, 23 June 2018, <>.

[DNS-RPZ] Vixie、P。およびV. Schryver、「DNS Response Policy Zones(RPZ)」、Work in Progress、Internet-Draft、draft-vixie-dnsop-dns-rpz-00、2018年6月23日、<https ://>。

[DNS64-Benchm] Lencse, G. and Y. Kadobayashi, "Benchmarking DNS64 Implementations: Theory and Practice", pp. 61-74, no. 1, vol. 127, Computer Communications, DOI 10.1016/j.comcom.2018.05.005, September 2018, < S0140366418302184?via%3Dihub>.

[DNS64-Benchm] Lencse、G。およびY. Kadobayashi、「DNS64実装のベンチマーク:理論と実践」、61〜74ページ、no。 1、vol。 127、Computer Communications、DOI 10.1016 / j.comcom.2018.05.005、2018年9月、< S0140366418302184?via%3Dihub>。

[DNS64-BM-Meth] Lencse, G., Georgescu, M., and Y. Kadobayashi, "Benchmarking Methodology for DNS64 Servers", pp. 162-175, no. 1, vol. 109, Computer Communications, DOI 10.1016/j.comcom.2017.06.004, September 2017, < S0140366416305904?via%3Dihub>.

[DNS64-BM-Meth] Lencse、G.、Georgescu、M。、およびY. Kadobayashi、「DNS64サーバーのベンチマーク手法」、pp。162-175、no。 1、vol。 109、Computer Communications、DOI 10.1016 / j.comcom.2017.06.004、2017年9月、< S0140366416305904?via%3Dihub>。

[FCC] FCC, "Measuring Broadband America Mobile 2013-2018 Coarsened Data", December 2018, < reports-research/reports/measuring-broadband-america/ measuring-broadband-america-mobile-2013-2018>.

[FCC] FCC、「Measuring Broadband America Mobile 2013-2018 Coarsened Data」、2018年12月、< reports-research / reports / measuring-broadband-america / Measurement-broadband-america-mobile -2013-2018>。

[IPV4ONLY-ARPA] Cheshire, S. and D. Schinazi, "Special Use Domain Name ''", Work in Progress, Internet-Draft, draft-cheshire-sudn-ipv4only-dot-arpa-14, 3 November 2018, <>.

[IPV4ONLY-ARPA] Cheshire、S。およびD. Schinazi、「特別用途ドメイン名「」」、進行中の作業、インターネットドラフト、draft-cheshire-sudn-ipv4only-dot-arpa-14、11月3日2018年、<>。

[IPv6-TRANSITION] Lencse, G., Palet, J., Howard, L., Patterson, R., and I. Farrer, "Pros and Cons of IPv6 Transition Technologies for IPv4aaS", Work in Progress, Internet-Draft, draft-lmhp-v6ops-transition-comparison-03, 6 July 2019, <>.

[IPv6-TRANSITION] Lencse、G.、Palet、J.、Howard、L.、Patterson、R.、I。Farrer、「IPv4aaSのためのIPv6移行テクノロジの長所と短所」、進行中の作業、インターネットドラフト、 draft-lmhp-v6ops-transition-comparison-03、2019年7月6日、<>。

[ISOC] ISOC, "State of IPv6 Deployment 2018", June 2018, <>.

[ISOC] ISOC、「State of IPv6 Deployment 2018」、2018年6月、<>。

[OPT-464XLAT] Palet, J. and A. D'Egidio, "464XLAT Optimization", Work in Progress, Internet-Draft, draft-palet-v6ops-464xlat-opt-cdn-caches-03, 8 July 2019, < draft-palet-v6ops-464xlat-opt-cdn-caches-03>.

[OPT-464XLAT] Palet、J。およびA. D'Egidio、「464XLAT最適化」、Work in Progress、Internet-Draft、draft-palet-v6ops-464xlat-opt-cdn-caches-03、2019年7月8日、< draft-palet-v6ops-464xlat-opt-cdn-caches-03>。

[PREF64] Colitti, L. and J. Linkova, "Discovering PREF64 in Router Advertisements", Work in Progress, Internet-Draft, draft-ietf-6man-ra-pref64-06, 3 October 2019, <>.

[PREF64] Colitti、L。およびJ. Linkova、「ルーターアドバタイズメントでのPREF64の発見」、Work in Progress、Internet-Draft、draft-ietf-6man-ra-pref64-06、2019年10月3日、<https:// tools / html / draft-ietf-6man-ra-pref64-06>。

[QUIC-CONNECTIONS] Huitema, C., Shore, M., Mankin, A., Dickinson, S., and J. Iyengar, "Specification of DNS over Dedicated QUIC Connections", Work in Progress, Internet-Draft, draft-huitema-quic-dnsoquic-07, 7 September 2019, <>.

[QUIC-CONNECTIONS] Huitema、C.、Shore、M.、Mankin、A.、Dickinson、S。、およびJ. Iyengar、「専用QUIC接続を介したDNSの仕様」、作業中、インターネットドラフト、ドラフト- huitema-quic-dnsoquic-07、2019年9月7日、<>。

[RFC6889] Penno, R., Saxena, T., Boucadair, M., and S. Sivakumar, "Analysis of Stateful 64 Translation", RFC 6889, DOI 10.17487/RFC6889, April 2013, <>.

[RFC6889] Penno、R.、Saxena、T.、Boucadair、M。、およびS. Sivakumar、「Analysis of Stateful 64 Translation」、RFC 6889、DOI 10.17487 / RFC6889、2013年4月、<https://www.rfc>。

[RFC6950] Peterson, J., Kolkman, O., Tschofenig, H., and B. Aboba, "Architectural Considerations on Application Features in the DNS", RFC 6950, DOI 10.17487/RFC6950, October 2013, <>.

[RFC6950] Peterson、J.、Kolkman、O.、Tschofenig、H。、およびB. Aboba、「DNSのアプリケーション機能に関するアーキテクチャ上の考慮事項」、RFC 6950、DOI 10.17487 / RFC6950、2013年10月、<https://>。

[RFC7051] Korhonen, J., Ed. and T. Savolainen, Ed., "Analysis of Solution Proposals for Hosts to Learn NAT64 Prefix", RFC 7051, DOI 10.17487/RFC7051, November 2013, <>.

[RFC7051]コルホネン、J。、エド。 T. Savolainen、編、「Analysis of Solution Proposals to Learn NAT64 Prefix」、RFC 7051、DOI 10.17487 / RFC7051、2013年11月、<>。

[RFC7269] Chen, G., Cao, Z., Xie, C., and D. Binet, "NAT64 Deployment Options and Experience", RFC 7269, DOI 10.17487/RFC7269, June 2014, <>.

[RFC7269] Chen、G.、Cao、Z.、Xie、C。、およびD. Binet、「NAT64 Deployment Options and Experience」、RFC 7269、DOI 10.17487 / RFC7269、2014年6月、<https://www.rfc>。

[RFC7755] Anderson, T., "SIIT-DC: Stateless IP/ICMP Translation for IPv6 Data Center Environments", RFC 7755, DOI 10.17487/RFC7755, February 2016, <>.

[RFC7755]アンダーソン、T。、「SIIT-DC:IPv6データセンター環境向けのステートレスIP / ICMP変換」、RFC 7755、DOI 10.17487 / RFC7755、2016年2月、< / rfc7755>。

[RFC7756] Anderson, T. and S. Steffann, "Stateless IP/ICMP Translation for IPv6 Internet Data Center Environments (SIIT-DC): Dual Translation Mode", RFC 7756, DOI 10.17487/RFC7756, February 2016, <>.

[RFC7756]アンダーソン、T。、およびS.ステファン、「IPv6インターネットデータセンター環境用のステートレスIP / ICMP変換(SIIT-DC):デュアル変換モード」、RFC 7756、DOI 10.17487 / RFC7756、2016年2月、<https:/ />。

[RFC7849] Binet, D., Boucadair, M., Vizdal, A., Chen, G., Heatley, N., Chandler, R., Michaud, D., Lopez, D., and W. Haeffner, "An IPv6 Profile for 3GPP Mobile Devices", RFC 7849, DOI 10.17487/RFC7849, May 2016, <>.

[RFC7849] Binet、D.、Boucadair、M.、Vizdal、A.、Chen、G.、Heatley、N.、Chandler、R.、Michaud、D.、Lopez、D。、およびW. Haeffner、「An 3GPPモバイルデバイスのIPv6プロファイル」、RFC 7849、DOI 10.17487 / RFC7849、2016年5月、<>。

[RFC7858] Hu, Z., Zhu, L., Heidemann, J., Mankin, A., Wessels, D., and P. Hoffman, "Specification for DNS over Transport Layer Security (TLS)", RFC 7858, DOI 10.17487/RFC7858, May 2016, <>.

[RFC7858] Hu、Z.、Zhu、L.、Heidemann、J.、Mankin、A.、Wessels、D。、およびP. Hoffman、「DNS over Transport Layer Security(TLS)の仕様」、RFC 7858、DOI 10.17487 / RFC7858、2016年5月、<>。

[RFC8094] Reddy, T., Wing, D., and P. Patil, "DNS over Datagram Transport Layer Security (DTLS)", RFC 8094, DOI 10.17487/RFC8094, February 2017, <>.

[RFC8094] Reddy、T.、Wing、D。、およびP. Patil、「DNS over Datagram Transport Layer Security(DTLS)」、RFC 8094、DOI 10.17487 / RFC8094、2017年2月、<https://www.rfc->。

[RFC8219] Georgescu, M., Pislaru, L., and G. Lencse, "Benchmarking Methodology for IPv6 Transition Technologies", RFC 8219, DOI 10.17487/RFC8219, August 2017, <>.

[RFC8219] Georgescu、M.、Pislaru、L。、およびG. Lencse、「IPv6 Transition Technologiesのベンチマーク手法」、RFC 8219、DOI 10.17487 / RFC8219、2017年8月、< / info / rfc8219>。

[RFC8585] Palet Martinez, J., Liu, H. M.-H., and M. Kawashima, "Requirements for IPv6 Customer Edge Routers to Support IPv4-as-a-Service", RFC 8585, DOI 10.17487/RFC8585, May 2019, <>.

[RFC8585] Palet Martinez、J.、Liu、HM-H。、M。Kawashima、「IPv6カスタマーエッジルーターがIPv4-as-a-Serviceをサポートするための要件」、RFC 8585、DOI 10.17487 / RFC8585、2019年5月、 <>。

[RIPE-690] RIPE, "Best Current Operational Practice for Operators: IPv6 prefix assignment for end-users - persistent vs non-persistent, and what size to choose", October 2017, <>.

[RIPE-690] RIPE、「オペレーター向けの現在のベストオペレーションプラクティス:エンドユーザーへのIPv6プレフィックス割り当て-永続的か非永続的か、どのサイズを選択するか」、2017年10月、< Publications / docs / ripe-690>。

[Threat-DNS64] Lencse, G. and Y. Kadobayashi, "Methodology for the identification of potential security issues of different IPv6 transition technologies: Threat analysis of DNS64 and stateful NAT64", pp. 397-411, no. 1, vol. 77, Computers & Security, DOI 10.1016/j.cose.2018.04.012, August 2018, < S0167404818303663?via%3Dihub>.

[Threat-DNS64] Lencse、G.およびY. Kadobayashi、「さまざまなIPv6移行テクノロジーの潜在的なセキュリティ問題を特定するための方法論:DNS64およびステートフルNAT64の脅威分析」、pp。397-411、no。 1、vol。 77、Computers&Security、DOI 10.1016 / j.cose.2018.04.012、August 2018、< S0167404818303663?via%3Dihub>。

Appendix A. Example of Broadband Deployment with 464XLAT
付録A. 464XLATを使用したブロードバンド展開の例

This section summarizes how an operator may deploy an IPv6-only network for residential/SOHO customers, supporting IPv6 inbound connections, and IPv4-as-a-Service (IPv4aaS) by using 464XLAT.

このセクションでは、464XLATを使用してIPv6インバウンド接続とIPv4-as-a-Service(IPv4aaS)をサポートし、オペレーターが住宅/ SOHOの顧客にIPv6のみのネットワークを展開する方法を要約します。

Note that an equivalent setup could also be provided for enterprise customers. If they need to support IPv4 inbound connections, several mechanisms, depending on specific customer needs, allow it; see [RFC7757].

同等の設定を企業のお客様にも提供できることに注意してください。 IPv4インバウンド接続をサポートする必要がある場合は、特定の顧客のニーズに応じて、いくつかのメカニズムで許可します。 [RFC7757]を参照してください。

Conceptually, most of the operator network could be IPv6 only (represented in the next figures as "IPv6-only flow"), or even if part of the network is actually dual stack, only IPv6 access is available for some customers (i.e., residential customers). This part of the network connects the IPv6-only subscribers (by means of IPv6-only access links) to the IPv6 upstream providers and to the IPv4-Internet by means of NAT64 (PLAT in the 464XLAT terminology).


The traffic flow from and back to the CE to services available in the IPv6 Internet (or even dual-stack remote services, when IPv6 is being used) is purely native IPv6 traffic, so there are no special considerations about it.


From the DNS perspective, there are remote networks with IPv4 only that will typically have only IPv4 DNS (DNS/IPv4) or will at least be seen as IPv4 DNS from the CE perspective. On the operator side, the DNS, as seen from the CE, is only IPv6 (DNS/IPv6), and it also has a DNS64 function.

DNSの観点から見ると、IPv4のみのリモートネットワークがあり、通常はIPv4 DNS(DNS / IPv4)のみを備えているか、少なくともCEの観点からはIPv4 DNSと見なされます。オペレーター側では、CEから見たDNSはIPv6のみ(DNS / IPv6)であり、DNS64機能も備えています。

On the customer LANs side, there is actually one network, which of course could be split into different segments. The most common setup will be dual-stack segments, using global IPv6 addresses and [RFC1918] for IPv4, in any regular residential / Small Office, Home Office (SOHO) IPv4 network. In the figure below, it is represented as tree segments to show that the three possible setups are valid (IPv6 only, IPv4 only, and dual stack).


         .-----.    +-------+     .-----.                   .-----.
        / IPv6- \   |       |    /       \                 /       \
       (  only   )--+ Res./ |   /  IPv6-  \    .-----.    /  IPv4-  \
        \ LANs  /   | SOHO  +--(   only    )--( NAT64 )--(   only    )
         `-----'    |       |   \  flow   /    `-----'    \  flow   /
         .-----.    | IPv6  |    \       /                 \       /
        / IPv4- \   |  CE   |     `--+--'                   `--+--'
       (  only   )--+ with  |        |                         |
        \ LANs  /   | CLAT  |    +---+----+                +---+----+
         `-----'    |       |    |DNS/IPv6|                |DNS/IPv4|
         .-----.    +---+---+    |  with  |                +--------+
        / Dual- \       |        | DNS64  |
       (  Stack  )------|        +--------+
        \ LANs  /

Figure 16: CE Setup with Built-In CLAT, with DNS64


In addition to the regular CE setup, which typically will be access-technology dependent, the steps for the CLAT function configuration can be summarized as follows:


1. Discovery of the PLAT (NAT64) prefix: It may be done using [RFC7050], [RFC7225] in those networks where PCP is supported, or other alternatives that may be available in the future, such as Router Advertising [PREF64] or DHCPv6 options [DHCPv6-OPTIONS].

1. PLAT(NAT64)プレフィックスの検出:PCPがサポートされているネットワークでは、[RFC7050]、[RFC7225]、またはルーターアドバタイズ[PREF64]やDHCPv6オプションなど、将来利用できる可能性のある他の代替手段を使用して行うことができます。 [DHCPv6-OPTIONS]。

2. If the CLAT function allows stateless NAT46 translation, a /64 from the pool typically provided to the CE by means of DHCPv6-PD [RFC8415] needs to be set aside for that translation. Otherwise, the CLAT is forced to perform an intermediate stateful NAT44 before the stateless NAT46, as described in Section 4.8.

2. CLAT機能がステートレスNAT46変換を許可する場合、通常、DHCPv6-PD [RFC8415]によってCEに提供されるプールからの/ 64は、その変換のために取っておかれる必要があります。それ以外の場合、セクション4.8で説明されているように、CLATはステートレスNAT46の前に中間のステートフルNAT44を実行する必要があります。

A more detailed configuration approach is described in [RFC8585].


The operator network needs to ensure that the correct responses are provided for the discovery of the PLAT prefix. It is highly recommended that [RIPE-690] be followed in order to ensure that multiple /64s are available, including the one needed for the NAT46 stateless translation.

事業者ネットワークは、PLATプレフィックスのディスカバリーに対して正しい応答が提供されるようにする必要があります。 NAT46ステートレス変換に必要な/ 64を含め、複数の/ 64を確実に使用できるようにするために、[RIPE-690]に従うことを強くお勧めします。

The operator needs to understand other issues, as described throughout this document, in order to make relevant decisions. For example, if several NAT64 functions are needed in the context of scalability / high availability, an NSP should be considered (see Section 4.5).


More complex scenarios are possible, for example, if a network offers multiple NAT64 prefixes, destination-based NAT64 prefixes, etc.


If the operator decides not to provide a DNS64 function, then this setup will be the same as the following figure. This will also be the setup that will be seen from the perspective of the CE, if a foreign DNS is used and consequently is not the operator-provided DNS64 function.


         .-----.    +-------+     .-----.                   .-----.
        / IPv6- \   |       |    /       \                 /       \
       (  only   )--+ Res./ |   /  IPv6-  \    .-----.    /  IPv4-  \
        \ LANs  /   | SOHO  +--(   only    )--( NAT64 )--(   only    )
         `-----'    |       |   \  flow   /    `-----'    \  flow   /
         .-----.    | IPv6  |    \       /                 \       /
        / IPv4- \   |  CE   |     `--+--'                   `--+--'
       (  only   )--+ with  |        |                         |
        \ LANs  /   | CLAT  |    +---+----+                +---+----+
         `-----'    |       |    |DNS/IPv6|                |DNS/IPv4|
         .-----.    +---+---+    +--------+                +--------+
        / Dual- \       |
       (  Stack  )------|
        \ LANs  /

Figure 17: CE Setup with Built-In CLAT, without DNS64


In this case, the discovery of the PLAT prefix needs to be arranged as indicated in Section 4.1.1.


In addition, if the CE doesn't have a built-in CLAT function, the customer can choose to set up the IPv6 operator-managed CE in bridge mode (and optionally use an external router). Or, for example, if there is an access technology that requires some kind of media converter (Optical Network Termination (ONT) for fiber to the home (FTTH), Cable Modem for Data-Over-Cable Service Interface Specification (DOCSIS), etc.), the complete setup will look like Figure 18. Obviously, there will be some intermediate configuration steps for the bridge, depending on the specific access technology/ protocols, which should not modify the steps already described in the previous cases for the CLAT function configuration.

さらに、CEにCLAT機能が組み込まれていない場合、顧客はIPv6オペレーター管理CEをブリッジモードでセットアップすることを選択できます(オプションで外部ルーターを使用します)。または、たとえば、ある種のメディアコンバーターを必要とするアクセステクノロジーがある場合(Fiber to the Home(FTTH)の光ネットワーク終端(ONT)、Data-Over-Cable Service Interface Specification(DOCSIS)のケーブルモデムなど) 。)、完全なセットアップは図18のようになります。明らかに、特定のアクセステクノロジー/プロトコルによっては、ブリッジの中間構成手順がいくつかあります。CLAT機能の前のケースですでに説明されている手順を変更しないでください。構成。

                    +-------+     .-----.                   .-----.
                    |       |    /       \                 /       \
                    | Res./ |   /  IPv6-  \    .-----.    /  IPv4-  \
                    | SOHO  +--(   only    )--( NAT64 )--(   only    )
                    |       |   \  flow   /    `-----'    \  flow   /
                    | IPv6  |    \       /                 \       /
                    |  CE   |     `--+--'                   `--+--'
                    | Bridge|        |                         |
                    |       |    +---+----+                +---+----+
                    |       |    |DNS/IPv6|                |DNS/IPv4|
                    +---+---+    +--------+                +--------+
         .-----.    +---+---+
        / IPv6- \   |       |
       (  only   )--+ IPv6  |
        \ LANs  /   | Router|
         `-----'    |       |
         .-----.    | with  |
        / IPv4- \   | CLAT  |
       (  only   )--+       |
        \ LANs  /   |       |
         `-----'    |       |
         .-----.    +---+---+
        / Dual- \       |
       (  Stack  )------|
        \ LANs  /

Figure 18: CE Setup with Bridged CLAT, without DNS64


Several routers (i.e., the operator-provided CE and the downstream user-provided router) that enable simultaneous routing and/or CLAT should be avoided to ensure that multiple NAT44 and NAT46 levels are not used and that the operation of multiple IPv6 subnets is correct. In those cases, the use of the Home Networking Control Protocol (HNCP) [RFC8375] is suggested.


Note that the procedure described here for the CE setup can be simplified if the CE follows [RFC8585].


Appendix B. CLAT Implementation
付録B. CLATの実装

In addition to the regular set of features for a CE, a CLAT CE implementation requires support for:

CEの通常の機能セットに加えて、CLAT CEの実装には次のサポートが必要です。

* [RFC7915] for the NAT46 function.

* [RFC7915] NAT46機能用。

* [RFC7050] for the PLAT prefix discovery.

* [RFC7050] PLATプレフィックスの検出。

* [RFC7225] for the PLAT prefix discovery if PCP is supported.

* [RFC7225] PCPがサポートされている場合のPLATプレフィックス検出。

* [PREF64] for the PLAT prefix discovery by means of Router Advertising.

* [PREF64]ルーターアドバタイズによるPLATプレフィックスの検出。

* [DHCPv6-OPTIONS] for the PLAT prefix discovery by means of DHCP.

* [DHCPv6-OPTIONS] DHCPを使用したPLATプレフィックス検出。

* If stateless NAT46 is supported, a mechanism to ensure that multiple /64 are available, such as DHCPv6-PD [RFC8415], must be used.

* ステートレスNAT46がサポートされている場合、DHCPv6-PD [RFC8415]など、複数の/ 64が使用可能であることを確認するメカニズムを使用する必要があります。

There are several Open Source implementations of CLAT, such as:


* Android:

* Android:

* Jool:

* ラグ:

* Linux:

* Linux:

* OpenWRT: &h=refs%2Ftags%2Fv19.07.0-rc1&st=commit&s=464xlat

* OpenWRT: = refs%2Ftags%2Fv19.07.0-rc1&st = commit&s = 464xlat

* VPP:

* VPP:

Appendix C. Benchmarking

A benchmarking methodology for IPv6 transition technologies has been defined in [RFC8219]. NAT64 and 464XLAT are addressed among the single- and double-translation technologies, respectively. DNS64 is addressed in Section 9, and the methodology is elaborated in [DNS64-BM-Meth] of that document.

IPv6移行テクノロジーのベンチマーク手法は[RFC8219]で定義されています。 NAT64と464XLATは、それぞれ単一および二重変換テクノロジで処理されます。 DNS64はセクション9で扱われ、その方法論はそのドキュメントの[DNS64-BM-Meth]で詳しく説明されています。

Several documents provide references to benchmarking results, for example, for DNS64 [DNS64-Benchm].

たとえば、DNS64 [DNS64-Benchm]のベンチマーク結果への参照を提供するドキュメントがいくつかあります。



The author would like to acknowledge the inputs of Gabor Lencse, Andrew Sullivan, Lee Howard, Barbara Stark, Fred Baker, Mohamed Boucadair, Alejandro D'Egidio, Dan Wing, Mikael Abrahamsson, and Eric Vyncke.

著者は、Gabor Lencse、Andrew Sullivan、Lee Howard、Barbara Stark、Fred Baker、Mohamed Boucadair、Alejandro D'Egidio、Dan Wing、Mikael Abrahamsson、およびEric Vynckeの入力を認めたいと思います。

Conversations with Marcelo Bagnulo, one of the coauthors of NAT64 and DNS64, and email correspondence via the IETF mailing lists with Mark Andrews have been very useful for this work.

NAT64とDNS64の共著者の1人であるMarcelo Bagnuloとの会話、およびMark AndrewsとのIETFメーリングリストを介した電子メール通信は、この作業に非常に役立ちました。

Work on this document was inspired by Christian Huitema, who suggested that DNS64 should never be used when deploying CLAT in the IETF network.

このドキュメントでの作業は、IETFネットワークにCLATを展開するときにDNS64を使用しないことを提案したChristian Huitemaに触発されました。

Author's Address


Jordi Palet Martinez The IPv6 Company Molino de la Navata, 75 28420 La Navata - Galapagar Madrid Spain

Jordi Palet Martinez The IPv6 Company Molino de la Navata、75 28420 La Navata-Galapagar Madrid Spain