Independent Submission F. Templin, Ed.
Request for Comments: 5558 Boeing Research & Technology
Category: Informational February 2010
ISSN: 2070-1721
Independent Submission F. Templin, Ed.
Request for Comments: 5558 Boeing Research & Technology
Category: Informational February 2010
ISSN: 2070-1721
Virtual Enterprise Traversal (VET)
虚拟企业遍历（VET）
Abstract
摘要
Enterprise networks connect routers over various link types, and may also connect to provider networks and/or the global Internet. Enterprise network nodes require a means to automatically provision IP addresses/prefixes and support internetworking operation in a wide variety of use cases including Small Office, Home Office (SOHO) networks, Mobile Ad hoc Networks (MANETs), multi-organizational corporate networks and the interdomain core of the global Internet itself. This document specifies a Virtual Enterprise Traversal (VET) abstraction for autoconfiguration and operation of nodes in enterprise networks.
企业网络通过各种链路类型连接路由器，还可以连接到提供商网络和/或全球互联网。企业网络节点需要一种方法来自动提供IP地址/前缀，并在各种各样的用例中支持互联网操作，包括小型办公室、家庭办公室（SOHO）网络、移动自组织网络（MANET）、多组织公司网络和全球互联网本身的域间核心。本文档为企业网络中节点的自动配置和操作指定了虚拟企业遍历（VET）抽象。
Status of This Memo
关于下段备忘
This document is not an Internet Standards Track specification; it is published for informational purposes.
本文件不是互联网标准跟踪规范；它是为了提供信息而发布的。
This is a contribution to the RFC Series, independently of any other RFC stream. The RFC Editor has chosen to publish this document at its discretion and makes no statement about its value for implementation or deployment. Documents approved for publication by the RFC Editor are not a candidate for any level of Internet Standard; see Section 2 of RFC 5741.
这是对RFC系列的贡献，独立于任何其他RFC流。RFC编辑器已选择自行发布此文档，并且未声明其对实现或部署的价值。RFC编辑批准发布的文件不适用于任何级别的互联网标准；见RFC 5741第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc5558.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问http://www.rfc-editor.org/info/rfc5558.
IESG Note
IESG注释
This RFC is not a candidate for any level of Internet Standard. The IETF disclaims any knowledge of the fitness of this RFC for any purpose and in particular notes that the decision to publish is not based on IETF review for such things as security, congestion control, or inappropriate interaction with deployed protocols. The RFC Editor has chosen to publish this document at its discretion. Readers of this RFC should exercise caution in evaluating its value for implementation and deployment. See RFC 3932 for more information.
本RFC不适用于任何级别的互联网标准。IETF不承认本RFC适用于任何目的的任何知识，特别注意到，发布决定并非基于IETF对安全、拥塞控制或与已部署协议的不当交互等事项的审查。RFC编辑已自行决定发布本文件。本RFC的读者应谨慎评估其实施和部署价值。有关更多信息，请参阅RFC 3932。
Note that the IETF AUTOCONF Working Group is working on a similar protocol solution that may become available in the future.
请注意，IETF AUTOCONF工作组正在研究一个类似的协议解决方案，该解决方案可能在将来可用。
Copyright Notice
版权公告
Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2010 IETF信托基金和确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) 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.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(http://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。
Table of Contents
目录
1. Introduction ....................................................4
2. Terminology .....................................................6
3. Enterprise Characteristics .....................................10
4. Autoconfiguration ..............................................11
4.1. Enterprise Router (ER) Autoconfiguration ..................12
4.2. Enterprise Border Router (EBR) Autoconfiguration ..........13
4.2.1. VET Interface Autoconfiguration ....................13
4.2.1.1. Interface Initialization ..................14
4.2.1.2. Enterprise Border Gateway
Discovery and Enterprise Identification ...14
4.2.1.3. EID Configuration .........................15
4.2.2. Provider-Aggregated (PA) EID Prefix
Autoconfiguration ..................................15
4.2.3. Provider-Independent (PI) EID Prefix
Autoconfiguration ..................................16
4.3. Enterprise Border Gateway (EBG) Autoconfiguration .........17
4.4. VET Host Autoconfiguration ................................17
5. Internetworking Operation ......................................18
5.1. Routing Protocol Participation ............................18
5.2. RLOC-Based Communications .................................18
5.3. EID-Based Communications ..................................18
5.4. IPv6 Router Discovery and Prefix Registration .............18
5.4.1. IPv6 Router and Prefix Discovery ...................18
5.4.2. IPv6 PA Prefix Registration ........................19
5.4.3. IPv6 PI Prefix Registration ........................20
5.4.4. IPv6 Next-Hop EBR Discovery ........................21
5.5. IPv4 Router Discovery and Prefix Registration .............23
5.6. VET Encapsulation .........................................24
5.7. SEAL Encapsulation ........................................24
5.8. Generating Errors .........................................25
5.9. Processing Errors .........................................25
5.10. Mobility and Multihoming Considerations ..................26
5.11. Multicast ................................................27
5.12. Service Discovery ........................................28
5.13. Enterprise Partitioning ..................................29
5.14. EBG Prefix State Recovery ................................29
6. Security Considerations ........................................30
7. Related Work ...................................................30
8. Acknowledgements ...............................................31
9. Contributors ...................................................31
10. References ....................................................31
10.1. Normative References .....................................31
10.2. Informative References ...................................33
Appendix A. Duplicate Address Detection (DAD) Considerations .... 36
1. Introduction ....................................................4
2. Terminology .....................................................6
3. Enterprise Characteristics .....................................10
4. Autoconfiguration ..............................................11
4.1. Enterprise Router (ER) Autoconfiguration ..................12
4.2. Enterprise Border Router (EBR) Autoconfiguration ..........13
4.2.1. VET Interface Autoconfiguration ....................13
4.2.1.1. Interface Initialization ..................14
4.2.1.2. Enterprise Border Gateway
Discovery and Enterprise Identification ...14
4.2.1.3. EID Configuration .........................15
4.2.2. Provider-Aggregated (PA) EID Prefix
Autoconfiguration ..................................15
4.2.3. Provider-Independent (PI) EID Prefix
Autoconfiguration ..................................16
4.3. Enterprise Border Gateway (EBG) Autoconfiguration .........17
4.4. VET Host Autoconfiguration ................................17
5. Internetworking Operation ......................................18
5.1. Routing Protocol Participation ............................18
5.2. RLOC-Based Communications .................................18
5.3. EID-Based Communications ..................................18
5.4. IPv6 Router Discovery and Prefix Registration .............18
5.4.1. IPv6 Router and Prefix Discovery ...................18
5.4.2. IPv6 PA Prefix Registration ........................19
5.4.3. IPv6 PI Prefix Registration ........................20
5.4.4. IPv6 Next-Hop EBR Discovery ........................21
5.5. IPv4 Router Discovery and Prefix Registration .............23
5.6. VET Encapsulation .........................................24
5.7. SEAL Encapsulation ........................................24
5.8. Generating Errors .........................................25
5.9. Processing Errors .........................................25
5.10. Mobility and Multihoming Considerations ..................26
5.11. Multicast ................................................27
5.12. Service Discovery ........................................28
5.13. Enterprise Partitioning ..................................29
5.14. EBG Prefix State Recovery ................................29
6. Security Considerations ........................................30
7. Related Work ...................................................30
8. Acknowledgements ...............................................31
9. Contributors ...................................................31
10. References ....................................................31
10.1. Normative References .....................................31
10.2. Informative References ...................................33
Appendix A. Duplicate Address Detection (DAD) Considerations .... 36
Enterprise networks [RFC4852] connect routers over various link types (see [RFC4861], Section 2.2). The term "enterprise network" in this context extends to a wide variety of use cases and deployment scenarios. For example, an "enterprise" can be as small as a SOHO network, as complex as a multi-organizational corporation, or as large as the global Internet itself. Mobile Ad hoc Networks (MANETs) [RFC2501] can also be considered as a challenging example of an enterprise network, in that their topologies may change dynamically over time and that they may employ little/no active management by a centralized network administrative authority. These specialized characteristics for MANETs require careful consideration, but the same principles apply equally to other enterprise network scenarios.
企业网络[RFC4852]通过各种链路类型连接路由器（参见[RFC4861]，第2.2节）。在此上下文中，术语“企业网络”扩展到各种各样的用例和部署场景。例如，“企业”可以小到SOHO网络，复杂到多组织公司，或者大到全球互联网本身。移动自组织网络（manet）[RFC2501]也可以被视为企业网络的一个具有挑战性的示例，因为它们的拓扑可以随着时间的推移而动态变化，并且它们可以通过集中式网络管理机构进行很少/没有的主动管理。移动自组网的这些特殊特性需要仔细考虑，但同样的原则同样适用于其他企业网络场景。
This document specifies a Virtual Enterprise Traversal (VET) abstraction for autoconfiguration and internetworking operation, where addresses of different scopes may be assigned on various types of interfaces with diverse properties. Both IPv4 [RFC0791] and IPv6 [RFC2460] are discussed within this context. The use of standard DHCP [RFC2131] [RFC3315] and neighbor discovery [RFC0826] [RFC1256] [RFC4861] mechanisms is assumed unless otherwise specified.
本文档规定了自动配置和网络互连操作的虚拟企业遍历（VET）抽象，其中不同范围的地址可分配到具有不同属性的各种类型的接口上。IPv4[RFC0791]和IPv6[RFC2460]都在本文中讨论。除非另有规定，否则假定使用标准DHCP[RFC2131][RFC3315]和邻居发现[RFC0826][RFC1256][RFC4861]机制。
Provider-Edge Interfaces
x x x
| | |
+--------------------+---+--------+----------+ E
| | | | | n
| I | | .... | | t
| n +---+---+--------+---+ | e
| t | +--------+ /| | r
| e I x----+ | Host | I /*+------+--< p I
| r n | |Function| n|**| | r n
| n t | +--------+ t|**| | i t
| a e x----+ V e|**+------+--< s e
| l r . | E r|**| . | e r
| f . | T f|**| . | f
| V a . | +--------+ a|**| . | I a
| i c . | | Router | c|**| . | n c
| r e x----+ |Function| e \*+------+--< t e
| t s | +--------+ \| | e s
| u +---+---+--------+---+ | r
| a | | .... | | i
| l | | | | o
+--------------------+---+--------+----------+ r
| | |
x x x
Enterprise-Edge Interfaces
Provider-Edge Interfaces
x x x
| | |
+--------------------+---+--------+----------+ E
| | | | | n
| I | | .... | | t
| n +---+---+--------+---+ | e
| t | +--------+ /| | r
| e I x----+ | Host | I /*+------+--< p I
| r n | |Function| n|**| | r n
| n t | +--------+ t|**| | i t
| a e x----+ V e|**+------+--< s e
| l r . | E r|**| . | e r
| f . | T f|**| . | f
| V a . | +--------+ a|**| . | I a
| i c . | | Router | c|**| . | n c
| r e x----+ |Function| e \*+------+--< t e
| t s | +--------+ \| | e s
| u +---+---+--------+---+ | r
| a | | .... | | i
| l | | | | o
+--------------------+---+--------+----------+ r
| | |
x x x
Enterprise-Edge Interfaces
Figure 1: Enterprise Router (ER) Architecture
图1：企业路由器（ER）体系结构
Figure 1 above depicts the architectural model for an Enterprise Router (ER). As shown in the figure, an ER may have a variety of interface types including enterprise-edge, enterprise-interior, provider-edge, internal-virtual, as well as VET interfaces used for IP-in-IP encapsulation. The different types of interfaces are defined, and the autoconfiguration mechanisms used for each type are specified. This architecture applies equally for MANET routers, in which enterprise-interior interfaces correspond to the wireless multihop radio interfaces typically associated with MANETs. Out of scope for this document is the autoconfiguration of provider interfaces, which must be coordinated in a manner specific to the service provider's network.
上面的图1描述了企业路由器（ER）的体系结构模型。如图所示，ER可以具有多种接口类型，包括企业边缘、企业内部、提供商边缘、内部虚拟以及用于IP-in-IP封装的VET接口。定义了不同类型的接口，并指定了用于每种类型的自动配置机制。该架构同样适用于MANET路由器，其中企业内部接口对应于通常与MANET相关联的无线多跳无线电接口。供应商接口的自动配置超出了本文档的范围，必须以特定于服务供应商网络的方式进行协调。
Enterprise networks must have a means for supporting both Provider-Independent (PI) and Provider-Aggregated (PA) IP prefixes. This is especially true for enterprise scenarios that involve mobility and multihoming. Also in scope are ingress filtering for multihomed sites, adaptation based on authenticated ICMP feedback from on-path routers, effective tunnel path MTU mitigations, and routing scaling suppression as required in many enterprise network scenarios.
企业网络必须具有支持独立于提供商（PI）和聚合提供商（PA）IP前缀的方法。对于涉及移动性和多宿的企业场景尤其如此。还包括多址站点的入口过滤、基于路径路由器的认证ICMP反馈的自适应、有效的隧道路径MTU缓解以及许多企业网络场景中所需的路由缩放抑制。
Recognizing that one size does not fit all, the VET specification provides adaptable mechanisms that address these issues, and more, in a wide variety of enterprise network use cases.
VET规范认识到一种规模并不能满足所有需求，因此它提供了可适应的机制，在各种企业网络用例中解决这些问题，甚至更多。
VET represents a functional superset of 6over4 [RFC2529] and Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) [RFC5214], and it further supports additional encapsulations such as IPsec [RFC4301], Subnetwork Encapsulation and Adaptation Layer (SEAL) [RFC5320], etc. Together, these technologies serve as functional building blocks for a new Internetworking architecture known as Routing and Addressing in Networks with Global Enterprise Recursion [RFC5720][RANGERS].
VET代表6over4[RFC2529]和站点内自动隧道寻址协议（ISATAP）[RFC5214]的功能超集，它进一步支持附加封装，如IPsec[RFC4301]、子网封装和适配层（SEAL）[RFC5320]等，这些技术作为一种新的网络互连体系结构的功能构建块，称为全球企业递归网络中的路由和寻址[RFC5720][RANGERS]。
The VET principles can be either directly or indirectly traced to the deliberations of the ROAD group in January 1992, and also to still earlier works including NIMROD [RFC1753], the Catenet model for internetworking [CATENET] [IEN48] [RFC2775], etc. [RFC1955] captures the high-level architectural aspects of the ROAD group deliberations in a "New Scheme for Internet Routing and Addressing (ENCAPS) for IPNG".
VET原则可以直接或间接追溯到1992年1月道路组的讨论，也可以追溯到更早的作品，包括NIMROD[RFC1753]、互联网络的Catenet模型[Catenet][IEN48][RFC2775]等[RFC1955]以一种全新的方式捕捉了道路组讨论的高层建筑方面“用于IPNG的Internet路由和寻址（ENCAPS）新方案”。
VET is related to the present-day activities of the IETF AUTOCONF, DHC, IPv6, MANET, and v6OPS working groups, as well as the IRTF RRG working group.
VET与IETF自动通信、DHC、IPv6、MANET和v6OPS工作组以及IRTF RRG工作组的当前活动有关。
The mechanisms within this document build upon the fundamental principles of IP-in-IP encapsulation. The terms "inner" and "outer" are used to, respectively, refer to the innermost IP {address, protocol, header, packet, etc.} *before* encapsulation, and the outermost IP {address, protocol, header, packet, etc.} *after* encapsulation. VET also allows for inclusion of "mid-layer" encapsulations between the inner and outer layers, including IPsec [RFC4301], the Subnetwork Encapsulation and Adaptation Layer (SEAL) [RFC5320], etc.
本文中的机制建立在IP-in-IP封装的基本原理之上。术语“内部”和“外部”分别指*封装前的最内部IP{地址、协议、报头、数据包等}*和*封装后的最外部IP{地址、协议、报头、数据包等}*。VET还允许在内层和外层之间包含“中间层”封装，包括IPsec[RFC4301]、子网封装和适配层（SEAL）[RFC5320]等。
The terminology in the normative references apply; the following terms are defined within the scope of this document:
规范性引用文件中的术语适用；本文件范围内定义了以下术语：
subnetwork the same as defined in [RFC3819].
子网络与[RFC3819]中的定义相同。
enterprise the same as defined in [RFC4852]. An enterprise is also understood to refer to a cooperative networked collective with a commonality of business, social, political, etc. interests.
与[RFC4852]中的定义相同。企业也被理解为是指具有商业、社会、政治等共同利益的合作网络集体。
Minimally, the only commonality of interest in some enterprise network scenarios may be the cooperative provisioning of connectivity itself.
至少，在某些企业网络场景中，唯一共同感兴趣的可能是连接本身的合作供应。
site a logical and/or physical grouping of interfaces that connect a topological area less than or equal to an enterprise in scope. A site within an enterprise can, in some sense, be considered as an enterprise unto itself.
站点连接范围小于或等于企业的拓扑区域的接口的逻辑和/或物理分组。从某种意义上讲，企业内的站点可以被视为自身的企业。
Mobile Ad hoc Network (MANET) a connected topology of mobile or fixed routers that maintain a routing structure among themselves over dynamic links, where a wide variety of MANETs share common properties with enterprise networks. The characteristics of MANETs are defined in [RFC2501], Section 3.
移动自组织网络（MANET）移动或固定路由器的连接拓扑，通过动态链路在它们之间维持路由结构，其中各种MANET与企业网络共享公共属性。[RFC2501]第3节定义了移动自组网的特性。
enterprise/site/MANET throughout the remainder of this document, the term "enterprise" is used to collectively refer to any of enterprise/site/MANET, i.e., the VET mechanisms and operational principles can be applied to enterprises, sites, and MANETs of any size or shape.
企业/站点/MANET在本文件的其余部分，术语“企业”用于统称任何企业/站点/MANET，即VET机制和操作原则可适用于任何规模或形状的企业、站点和MANET。
Enterprise Router (ER) As depicted in Figure 1, an Enterprise Router (ER) is a fixed or mobile router that comprises a router function, a host function, one or more enterprise-interior interfaces, and zero or more internal virtual, enterprise-edge, provider-edge, and VET interfaces. At a minimum, an ER forwards outer IP packets over one or more sets of enterprise-interior interfaces, where each set connects to a distinct enterprise.
企业路由器（ER）如图1所示，企业路由器（ER）是由路由器功能、主机功能、一个或多个企业内部接口以及零个或多个内部虚拟、企业边缘、提供商边缘和VET接口组成的固定或移动路由器。至少，ER通过一组或多组企业内部接口转发外部IP数据包，其中每组都连接到不同的企业。
Enterprise Border Router (EBR) an ER that connects edge networks to the enterprise and/or connects multiple enterprises together. An EBR is a tunnel endpoint router, and it configures a separate VET interface over each set of enterprise-interior interfaces that connect the EBR to each distinct enterprise. In particular, an EBR may configure multiple VET interfaces -- one for each distinct enterprise. All EBRs are also ERs.
企业边界路由器（EBR）：将边缘网络连接到企业和/或将多个企业连接在一起的ER。EBR是隧道端点路由器，它在将EBR连接到每个不同企业的每组企业内部接口上配置单独的VET接口。特别是，EBR可以配置多个VET接口——每个不同的企业一个。所有欧洲复兴开发银行也都是欧洲复兴开发银行。
Enterprise Border Gateway (EBG) an EBR that connects VET interfaces configured over child enterprises to a provider network -- either directly via a provider-edge interface or indirectly via another VET interface configured over a parent enterprise. EBRs may act as EBGs on some VET interfaces and as ordinary EBRs on other VET interfaces. All EBGs are also EBRs.
企业边界网关（EBG）一种EBR，它将通过子企业配置的VET接口直接连接到提供商网络，或者通过提供商边缘接口，或者通过通过通过父企业配置的另一个VET接口间接连接。EBR可在某些VET接口上充当EBG，在其他VET接口上充当普通EBR。所有EBG也是EBR。
enterprise-interior interface an ER's attachment to a link within an enterprise. Packets sent over enterprise-interior interfaces may be forwarded over multiple additional enterprise-interior interfaces within the enterprise before they are forwarded via an enterprise-edge interface, provider-edge interface, or a VET interface configured over a different enterprise. Enterprise-interior interfaces connect laterally within the IP network hierarchy.
企业内部接口企业内部链接的ER附件。通过企业内部接口发送的数据包可以在通过企业边缘接口、提供商边缘接口或通过不同企业配置的VET接口转发之前，通过企业内部的多个附加企业内部接口转发。企业内部接口在IP网络层次结构中横向连接。
enterprise-edge interface an EBR's attachment to a link (e.g., an Ethernet, a wireless personal area network, etc.) on an arbitrarily complex edge network that the EBR connects to an enterprise and/or provider network. Enterprise-edge interfaces connect to lower levels within the IP network hierarchy.
企业边缘接口EBR与任意复杂边缘网络上的链路（如以太网、无线个人区域网络等）的连接，EBR连接到企业和/或提供商网络。企业边缘接口连接到IP网络层次结构中的较低级别。
provider-edge interface an EBR's attachment to the Internet or to a provider network outside of the enterprise via which the Internet can be reached. Provider-edge interfaces connect to higher levels within the IP network hierarchy.
提供商边缘接口EBR与Internet或企业外部提供商网络的连接，通过该连接可以访问Internet。提供程序边缘接口连接到IP网络层次结构中的更高级别。
internal-virtual interface an interface that is internal to an EBR and does not in itself directly attach to a tangible physical link, e.g., an Ethernet cable. Examples include a loopback interface, a virtual LAN interface, or some form of tunnel interface.
内部虚拟接口EBR内部的接口，其本身不直接连接到有形物理链路，例如以太网电缆。示例包括环回接口、虚拟LAN接口或某种形式的隧道接口。
Virtual Enterprise Traversal (VET) an abstraction that uses IP-in-IP encapsulation to create an overlay that spans an enterprise in a single (inner) IP hop.
虚拟企业遍历（VET）一种抽象，它使用IP-in-IP封装来创建覆盖，该覆盖在单个（内部）IP跃点中跨越企业。
VET interface an EBR's tunnel virtual interface used for Virtual Enterprise Traversal. The EBR configures a VET interface over a set of underlying interfaces belonging to the same enterprise. When there are multiple distinct enterprises (each with their own distinct set of underlying interfaces), the EBR configures a separate VET interface over each set of underlying interfaces, i.e., the EBR configures multiple VET interfaces.
VET接口用于虚拟企业遍历的EBR隧道虚拟接口。EBR在属于同一企业的一组基础接口上配置VET接口。当存在多个不同的企业（每个企业都有各自不同的基础接口集）时，EBR在每一组基础接口上配置一个单独的VET接口，即EBR配置多个VET接口。
The VET interface encapsulates each inner IP packet in any mid-layer headers plus an outer IP header, then it forwards it on an underlying interface such that the Time to Live (TTL) / Hop Limit in the inner header is not decremented as the packet traverses the enterprise. The VET interface therefore presents an automatic tunneling abstraction that represents the enterprise as a single IP hop.
VET接口将每个内部IP数据包封装在任何中间层报头加上一个外部IP报头中，然后在底层接口上转发它，以便在数据包穿越企业时，内部报头中的生存时间（TTL）/跃点限制不会减少。因此，VET接口提供了一个自动隧道抽象，将企业表示为单个IP跃点。
VET interfaces in non-multicast environments are Non-Broadcast, Multiple Access (NBMA); VET interfaces in multicast environments are multicast capable.
非多播环境中的VET接口为非广播多址（NBMA）；多播环境中的VET接口支持多播。
VET host any node (host or router) that configures a VET interface for host operation only. Note that a single node may configure some of its VET interfaces as host interfaces and others as router interfaces.
VET host仅为主机操作配置VET接口的任何节点（主机或路由器）。请注意，单个节点可能会将其一些VET接口配置为主机接口，而将另一些配置为路由器接口。
VET node any node that configures and uses a VET interface.
VET节点配置和使用VET接口的任何节点。
Provider-Independent (PI) prefix an IPv6 or IPv4 prefix (e.g., 2001:DB8::/48, 192.0.2/24, etc.) that is either self-generated by an ER or delegated to an enterprise by a registry.
独立于提供商（PI）前缀由ER自行生成或由注册中心委托给企业的IPv6或IPv4前缀（例如，2001:DB8:：/48、192.0.2/24等）。
Provider Aggregated (PA) prefix an IPv6 or IPv4 prefix that is delegated to an enterprise by a provider network.
提供商聚合（PA）前缀由提供商网络委派给企业的IPv6或IPv4前缀。
Routing Locator (RLOC) a non-link-local IPv4 or IPv6 address taken from a PI/PA prefix that can appear in enterprise-interior and/or interdomain routing tables. Global-scope RLOC prefixes are delegated to specific enterprises and are routable within both the enterprise-interior and interdomain routing regions. Enterprise-local-scope RLOC prefixes (e.g., IPv6 Unique Local Addresses [RFC4193], IPv4 privacy addresses [RFC1918], etc.) are self-generated by individual enterprises and routable only within the enterprise-interior routing region.
路由定位器（RLOC）：从PI/PA前缀获取的非链路本地IPv4或IPv6地址，可出现在企业内部和/或域间路由表中。全局范围RLOC前缀被委托给特定的企业，并且可以在企业内部和域间路由区域内路由。企业本地范围RLOC前缀（例如IPv6唯一本地地址[RFC4193]、IPv4隐私地址[RFC1918]等）由单个企业自行生成，并且只能在企业内部路由区域内路由。
ERs use RLOCs for operating the enterprise-interior routing protocol and for next-hop determination in forwarding packets addressed to other RLOCs. End systems use RLOCs as addresses for communications between endpoints within the same enterprise. VET interfaces treat RLOCs as *outer* IP addresses during IP-in-IP encapsulation.
ERs使用RLOC来操作企业内部路由协议，并在将数据包转发到其他RLOC时确定下一跳。终端系统使用RLOC作为同一企业内端点之间通信的地址。在IP-in-IP封装期间，VET接口将RLOC视为*外部*IP地址。
Endpoint Interface iDentifier (EID) an IPv4 or IPv6 address taken from a PI/PA prefix that is routable within an enterprise-edge or VET overlay network scope, and may also appear in enterprise-interior and/or interdomain mapping tables. EID prefixes are typically separate and distinct from any RLOC prefix space.
端点接口标识符（EID）：取自PI/PA前缀的IPv4或IPv6地址，可在企业边缘或VET覆盖网络范围内路由，也可出现在企业内部和/或域间映射表中。EID前缀通常独立于任何RLOC前缀空间。
Edge network routers use EIDs for operating the enterprise-edge or VET overlay network routing protocol and for next-hop determination in forwarding packets addressed to other EIDs. End systems use EIDs as addresses for communications between endpoints either within the same enterprise or within different enterprises. VET interfaces treat EIDs as *inner* IP addresses during IP-in-IP encapsulation.
边缘网络路由器使用EID操作企业边缘或VET覆盖网络路由协议，并在将数据包转发到其他EID时确定下一跳。终端系统使用EID作为同一企业内或不同企业内端点之间通信的地址。在IP-in-IP封装期间，VET接口将EID视为*内部*IP地址。
The following additional acronyms are used throughout the document:
本文件中使用了以下其他首字母缩略词：
CGA - Cryptographically Generated Address
DHCP(v4, v6) - Dynamic Host Configuration Protocol
FIB - Forwarding Information Base
ISATAP - Intra-Site Automatic Tunnel Addressing Protocol
NBMA - Non-Broadcast, Multiple Access
ND - Neighbor Discovery
PIO - Prefix Information Option
PRL - Potential Router List
PRLNAME - Identifying name for the PRL (default is "isatap")
RIO - Route Information Option
RS/RA - IPv6 ND Router Solicitation/Advertisement
SEAL - Subnetwork Encapsulation and Adaptation Layer
SLAAC - IPv6 StateLess Address AutoConfiguation
CGA - Cryptographically Generated Address
DHCP(v4, v6) - Dynamic Host Configuration Protocol
FIB - Forwarding Information Base
ISATAP - Intra-Site Automatic Tunnel Addressing Protocol
NBMA - Non-Broadcast, Multiple Access
ND - Neighbor Discovery
PIO - Prefix Information Option
PRL - Potential Router List
PRLNAME - Identifying name for the PRL (default is "isatap")
RIO - Route Information Option
RS/RA - IPv6 ND Router Solicitation/Advertisement
SEAL - Subnetwork Encapsulation and Adaptation Layer
SLAAC - IPv6 StateLess Address AutoConfiguation
Enterprises consist of links that are connected by Enterprise Routers (ERs) as depicted in Figure 1. ERs typically participate in a routing protocol over enterprise-interior interfaces to discover routes that may include multiple Layer 2 or Layer 3 forwarding hops. Enterprise Border Routers (EBRs) are ERs that connect edge networks to the enterprise and/or join multiple enterprises together. Enterprise Border Gateways (EBGs) are EBRs that either directly or indirectly connect enterprises to provider networks.
企业由企业路由器（ER）连接的链路组成，如图1所示。ER通常通过企业内部接口参与路由协议，以发现可能包括多个第2层或第3层转发跃点的路由。企业边界路由器（EBR）是将边缘网络连接到企业和/或将多个企业连接在一起的路由器。企业边界网关（EBG）是直接或间接将企业连接到提供商网络的EBR。
An enterprise may be as simple as a small collection of ERs and their attached edge networks; an enterprise may also contain other enterprises and/or be a subnetwork of a larger enterprise. An enterprise may further encompass a set of branch offices and/or nomadic hosts connected to a home office over one or several service providers, e.g., through Virtual Private Network (VPN) tunnels.
一个企业可以简单到一小部分ER及其连接的边缘网络；企业还可能包含其他企业和/或是较大企业的子网络。企业还可以包括通过一个或多个服务提供商（例如，通过虚拟专用网络（VPN）隧道）连接到家庭办公室的一组分支办公室和/或游牧主机。
Enterprises that comprise link types with sufficiently similar properties (e.g., Layer 2 (L2) address formats, maximum transmission units (MTUs), etc.) can configure a sub-IP layer routing service such that IP sees the enterprise as an ordinary shared link the same as for a (bridged) campus LAN. In that case, a single IP hop is sufficient to traverse the enterprise without IP layer encapsulation.
包含具有足够相似属性（例如，第2层（L2）地址格式、最大传输单元（MTU）等）的链路类型的企业可以配置子IP层路由服务，以便IP将企业视为与（桥接）校园LAN相同的普通共享链路。在这种情况下，单个IP跃点足以在没有IP层封装的情况下遍历企业。
Enterprises that comprise link types with diverse properties and/or configure multiple IP subnets must also provide a routing service that operates as an IP layer mechanism. In that case, multiple IP hops may be necessary to traverse the enterprise such that care must be taken to avoid multi-link subnet issues [RFC4903].
包含具有不同属性的链路类型和/或配置多个IP子网的企业还必须提供作为IP层机制运行的路由服务。在这种情况下，可能需要多个IP跃点来遍历企业，因此必须小心避免多链路子网问题[RFC4903]。
Conceptually, an ER embodies both a host function and router function. The host function supports Endpoint Interface iDentifier (EID)-based and/or Routing LOCator (RLOC)-based communications according to the weak end-system model [RFC1122]. The router function engages in the enterprise-interior routing protocol, connects any of the ER's edge networks to the enterprise, and may also connect the enterprise to provider networks (see Figure 1).
从概念上讲，ER同时体现了主机功能和路由器功能。根据弱端系统模型[RFC1122]，主机功能支持基于端点接口标识符（EID）和/或基于路由定位器（RLOC）的通信。路由器功能参与企业内部路由协议，将ER的任何边缘网络连接到企业，还可以将企业连接到提供商网络（见图1）。
In addition to other interface types, VET nodes configure VET interfaces that view all other VET nodes in an enterprise as single-hop neighbors attached to a virtual link. VET nodes configure a separate VET interface for each distinct enterprise to which they connect, and discover other EBRs on each VET interface that can be used for forwarding packets to off-enterprise destinations.
除其他接口类型外，VET节点还配置VET接口，将企业中的所有其他VET节点视为连接到虚拟链路的单跳邻居。VET节点为其连接的每个不同企业配置单独的VET接口，并在每个VET接口上发现可用于将数据包转发到非企业目的地的其他EBR。
For each distinct enterprise, an enterprise trust basis must be established and consistently applied. For example, in enterprises in which EBRs establish symmetric security associations, mechanisms such as IPsec [RFC4301] can be used to assure authentication and confidentiality. In other enterprise network scenarios, asymmetric securing mechanisms such as SEcure Neighbor Discovery (SEND) [RFC3971] may be necessary to authenticate exchanges based on trust anchors.
对于每一个不同的企业，必须建立并一致应用企业信托基础。例如，在EBR建立对称安全关联的企业中，可以使用IPsec[RFC4301]等机制来确保身份验证和机密性。在其他企业网络场景中，可能需要诸如安全邻居发现（SEND）[RFC3971]之类的非对称安全机制来基于信任锚对交换进行身份验证。
Finally, in enterprises with a centralized management structure (e.g., a corporate campus network), the enterprise name service and a synchronized set of EBGs can provide infrastructure support for virtual enterprise traversal. In that case, the EBGs can provide a "default mapper" [APT] service used for short-term packet forwarding until EBR neighbor relationships can be established. In enterprises with a distributed management structure (e.g., MANETs), peer-to-peer coordination between the EBRs themselves may be required. Recognizing that various use cases will entail a continuum between a fully distributed and fully centralized approach, the following sections present the mechanisms of Virtual Enterprise Traversal as they apply to a wide variety of scenarios.
最后，在具有集中管理结构的企业中（例如，企业校园网），企业名称服务和一组同步的EBG可以为虚拟企业遍历提供基础设施支持。在这种情况下，EBG可以提供用于短期分组转发的“默认映射器”[APT]服务，直到可以建立EBR邻居关系。在具有分布式管理结构（如MANET）的企业中，可能需要EBR之间的点对点协调。认识到各种用例将在完全分布式和完全集中的方法之间形成一个连续统一体，以下各节介绍了虚拟企业遍历的机制，因为它们适用于各种各样的场景。
ERs, EBRs, EBGs, and VET hosts configure themselves for operation as specified in the following subsections.
ERs、EBR、EBGs和VET主机按照以下小节中的规定配置自己的操作。
ERs configure enterprise-interior interfaces and engage in any routing protocols over those interfaces.
ERs配置企业内部接口，并参与这些接口上的任何路由协议。
When an ER joins an enterprise, it first configures a unique IPv6 link-local address on each enterprise-interior interface and configures an IPv4 link-local address on each enterprise-interior interface that requires an IPv4 link-local capability. IPv6 link-local address generation mechanisms that provide sufficient uniqueness include Cryptographically Generated Addresses (CGAs) [RFC3972], IPv6 Privacy Addresses [RFC4941], StateLess Address AutoConfiguration (SLAAC) using EUI-64 interface identifiers [RFC4291] [RFC4862], etc. The mechanisms specified in [RFC3927] provide an IPv4 link-local address generation capability.
当ER加入企业时，它首先在每个企业内部接口上配置唯一的IPv6链路本地地址，并在每个需要IPv4链路本地功能的企业内部接口上配置IPv4链路本地地址。提供足够唯一性的IPv6链路本地地址生成机制包括加密生成地址（CGA）[RFC3972]、IPv6隐私地址[RFC4941]、使用EUI-64接口标识符[RFC4291][RFC4862]的无状态地址自动配置（SLAAC）等。在[RFC3927]中指定的机制提供IPv4链路本地地址生成功能。
Next, the ER configures an RLOC on each of its enterprise-interior interfaces and engages in any routing protocols on those interfaces. The ER can configure an RLOC via explicit management, DHCP autoconfiguration, pseudo-random self-generation from a suitably large address pool, or through an alternate autoconfiguration mechanism.
接下来，ER在其每个企业内部接口上配置RLOC，并参与这些接口上的任何路由协议。ER可以通过显式管理、DHCP自动配置、从适当大的地址池伪随机自生成或通过备用自动配置机制来配置RLOC。
Alternatively (or in addition), the ER can request RLOC prefix delegations via an automated prefix delegation exchange over an enterprise-interior interface and can assign the prefix(es) on enterprise-edge interfaces. In that case, the ER can use an RLOC assigned to an enterprise-edge interface for enterprise-interior routing protocol operation and next-hop determination purposes. Note that in some cases, the same enterprise-edge interfaces may assign both RLOC and an EID addresses if there is a means for source address selection. In other cases (e.g., for separation of security domains), RLOCs and EIDs must be assigned on separate sets of enterprise-edge interfaces.
或者（或者另外），ER可以通过企业内部接口上的自动前缀委派交换请求RLOC前缀委派，并且可以在企业边缘接口上分配前缀。在这种情况下，ER可以将分配给企业边缘接口的RLOC用于企业内部路由协议操作和下一跳确定目的。注意，在某些情况下，如果有选择源地址的方法，相同的企业边缘接口可能同时分配RLOC和EID地址。在其他情况下（例如，为了分离安全域），必须在不同的企业边缘接口集上分配RLOC和EID。
Self-generation of RLOCs for IPv6 can be from a large IPv6 local-use address range, e.g., IPv6 Unique Local Addresses [RFC4193]. Self-generation of RLOCs for IPv4 can be from a large IPv4 private address range (e.g., [RFC1918]). When self-generation is used alone, the ER must continuously monitor the RLOCs for uniqueness, e.g., by monitoring the routing protocol.
用于IPv6的RLOC的自生成可以来自较大的IPv6本地使用地址范围，例如IPv6唯一本地地址[RFC4193]。IPv4的RLOC可以从较大的IPv4专用地址范围（例如[RFC1918]）自行生成。当单独使用自生成时，ER必须持续监控RLOCs的唯一性，例如，通过监控路由协议。
DHCP generation of RLOCs may require support from relays within the enterprise. For DHCPv6, relays that do not already know the RLOC of a server within the enterprise forward requests to the 'All_DHCP_Servers' site-scoped IPv6 multicast group [RFC3315]. For DHCPv4, relays that do not already know the RLOC of a server within the enterprise forward requests to the site-scoped IPv4 multicast
RLOC的DHCP生成可能需要企业内中继的支持。对于DHCPv6，尚未知道企业内服务器的RLOC的中继将请求转发到“所有DHCP服务器”站点范围的IPv6多播组[RFC3315]。对于DHCPv4，尚未知道企业内服务器的RLOC的中继将请求转发到站点范围的IPv4多播
group address 'All_DHCPv4_Servers', which should be set to 239.255.2.1 unless an alternate multicast group for the site is known. DHCPv4 servers that delegate RLOCs should therefore join the 'All_DHCPv4_Servers' multicast group and service any DHCPv4 messages received for that group.
组地址“All_DHCPv4_Servers”，应设置为239.255.2.1，除非已知站点的备用多播组。因此，委托RLOC的DHCPv4服务器应加入“所有DHCPv4\u服务器”多播组，并为该组接收的任何DHCPv4消息提供服务。
A combined approach using both DHCP and self-generation is also possible when the ER configures both a DHCP client and relay that are connected, e.g., via a pair of back-to-back connected Ethernet interfaces, a tun/tap interface, a loopback interface, inter-process communication, etc. The ER first self-generates a temporary RLOC used only for the purpose of procuring an actual RLOC taken from a disjoint addressing range. The ER then engages in the routing protocol and performs a DHCP client/relay exchange using the temporary RLOC as the address of the relay. When the DHCP server delegates an actual RLOC address/prefix, the ER abandons the temporary RLOC and re-engages in the routing protocol using an RLOC taken from the delegation.
当ER配置连接的DHCP客户端和中继（例如，通过一对背对背连接的以太网接口、tun/tap接口、环回接口、进程间通信、，等等。ER第一自生成临时RLOC，该临时RLOC仅用于从不相交的寻址范围获取实际RLOC。然后，ER参与路由协议并使用临时RLOC作为中继地址执行DHCP客户端/中继交换。当DHCP服务器委托实际RLOC地址/前缀时，ER放弃临时RLOC，并使用从委托中获取的RLOC重新参与路由协议。
In some enterprise use cases (e.g., MANETs), assignment of RLOCs on enterprise-interior interfaces as singleton addresses (i.e., as addresses with /32 prefix lengths for IPv4, and as addresses with /128 prefix lengths for IPv6) may be necessary to avoid multi-link subnet issues.
在某些企业使用案例中（例如，移动自组网），为避免多链路子网问题，可能需要在企业内部接口上将RLOC分配为单件地址（即，对于IPv4，分配为前缀长度为/32的地址，对于IPv6，分配为前缀长度为/128的地址）。
EBRs are ERs that configure VET interfaces over distinct sets of underlying interfaces belonging to the same enterprise; an EBR can connect to multiple enterprises, in which case it would configure multiple VET interfaces. In addition to the ER autoconfiguration procedures specified in Section 4.1, EBRs perform the following autoconfiguration operations.
EBR是在属于同一企业的不同底层接口集上配置VET接口的ER；EBR可以连接到多个企业，在这种情况下，它将配置多个VET接口。除第4.1节规定的ER自动配置程序外，EBR还执行以下自动配置操作。
VET interface autoconfiguration entails:
VET接口自动配置需要：
1) interface initialization, 2) EBG discovery and enterprise identification, and 3) EID configuration.
1) 接口初始化，2）EBG发现和企业标识，以及3）EID配置。
These functions are specified in the following sections.
这些功能在以下章节中有详细说明。
EBRs configure a VET interface over a set of underlying interfaces belonging to the same enterprise, where the VET interface presents a virtual-link abstraction in which all EBRs in the enterprise appear as single-hop neighbors through the use of IP-in-IP encapsulation. After the EBR configures a VET interface, it initializes the interface and assigns an IPv6 link-local address and an IPv4 link-local address if necessary.
EBR在属于同一企业的一组底层接口上配置VET接口，其中VET接口呈现虚拟链路抽象，其中企业中的所有EBR通过使用IP-in-IP封装显示为单跳邻居。EBR配置VET接口后，将初始化接口，并根据需要分配IPv6链路本地地址和IPv4链路本地地址。
When IPv6 and IPv4 are used as the inner/outer protocols (respectively), the EBR autoconfigures an ISATAP link-local address ([RFC5214], Section 6.2) on the VET interface to support packet forwarding and operation of the IPv6 neighbor discovery protocol. The ISATAP link-local address embeds an IPv4 RLOC, and need not be checked for uniqueness since the IPv4 RLOC itself is managed for uniqueness (see Section 4.1).
当IPv6和IPv4分别用作内部/外部协议时，EBR会在VET接口上自动配置ISATAP链路本地地址（[RFC5214]，第6.2节），以支持IPv6邻居发现协议的数据包转发和操作。ISATAP链路本地地址嵌入IPv4 RLOC，无需检查其唯一性，因为IPv4 RLOC本身是为唯一性而管理的（请参见第4.1节）。
Link-local address configuration for other inner/outer IP protocol combinations is through administrative configuration or through an unspecified alternate method. Link-local address configuration for other inner/outer IP protocol combinations may not be necessary if an EID can be configured through other means (see Section 4.2.1.3).
其他内部/外部IP协议组合的链路本地地址配置通过管理配置或未指定的替代方法进行。如果可以通过其他方式配置EID，则可能不需要为其他内部/外部IP协议组合配置链路本地地址（见第4.2.1.3节）。
After the EBR initializes a VET interface, it can communicate with other VET nodes as single-hop neighbors on the VET interface from the viewpoint of the inner IP protocol.
EBR初始化VET接口后，从内部IP协议的角度来看，它可以作为VET接口上的单跳邻居与其他VET节点通信。
4.2.1.2. Enterprise Border Gateway Discovery and Enterprise Identification
4.2.1.2. 企业边界网关发现和企业标识
The EBR next discovers a list of EBGs for each of its VET interfaces. The list can be discovered through information conveyed in the routing protocol, through the Potential Router List (PRL) discovery mechanisms outlined in Section 8.3.2 of [RFC5214], through DHCP options, etc. In multicast-capable enterprises, EBRs can also listen for advertisements on the 'rasadv' [RASADV] multicast group address.
EBR接下来会发现其每个VET接口的EBG列表。可以通过路由协议中传输的信息、通过[RFC5214]第8.3.2节中概述的潜在路由器列表（PRL）发现机制、通过DHCP选项等发现列表。在支持多播的企业中，EBR还可以侦听“RASAV”[RASAV]多播组地址上的广告。
In particular, whether or not routing information is available, the EBR can discover the list of EBGs by resolving an identifying name for the PRL ('PRLNAME') formed as 'hostname.domainname', where 'hostname' is an enterprise-specific name string and 'domainname' is an enterprise-specific DNS suffix. The EBR discovers 'PRLNAME' through manual configuration, a DHCP option, 'rasadv' protocol advertisements, link-layer information (e.g., an IEEE 802.11 Service Set Identifier (SSID)), or through some other means specific to the enterprise. In the absence of other information, the EBR sets the
特别是，无论路由信息是否可用，EBR都可以通过解析形成为“hostname.domainname”的PRL的标识名（“PRLNAME”）来发现EBG列表，其中“hostname”是企业特定的名称字符串，“domainname”是企业特定的DNS后缀。EBR通过手动配置、DHCP选项、“RASAV”协议公告、链路层信息（例如IEEE 802.11服务集标识符（SSID））或通过特定于企业的其他方式发现“PRLNAME”。在没有其他信息的情况下，欧洲复兴开发银行将
'hostname' component of 'PRLNAME' to "isatap" and sets the 'domainname' component only if an enterprise-specific DNS suffix "example.com" is known (e.g., as "isatap.example.com").
“PRLNAME”的“hostname”组件设置为“isatap”，并且仅当已知特定于企业的DNS后缀“example.com”（例如“isatap.example.com”）时才设置“domainname”组件。
The global Internet interdomain routing core represents a specific example of an enterprise network scenario, albeit on an enormous scale. The 'PRLNAME' assigned to the global Internet interdomain routing core is "isatap.net".
全球互联网域间路由核心代表了企业网络场景的一个具体示例，尽管规模巨大。分配给全局Internet域间路由核心的“PRLNAME”是“isatap.net”。
After discovering 'PRLNAME', the EBR can discover the list of EBGs by resolving 'PRLNAME' to a list of RLOC addresses through a name service lookup. For centrally managed enterprises, the EBR resolves 'PRLNAME' using an enterprise-local name service (e.g., the enterprise-local DNS). For enterprises with a distributed management structure, the EBR resolves 'PRLNAME' using Link-Local Multicast Name Resolution (LLMNR) [RFC4795] over the VET interface. In that case, all EBGs in the PRL respond to the LLMNR query, and the EBR accepts the union of all responses.
在发现“PRLNAME”后，EBR可以通过名称服务查找将“PRLNAME”解析为RLOC地址列表来发现EBG列表。对于集中管理的企业，EBR使用企业本地名称服务（例如，企业本地DNS）解析“PRLNAME”。对于具有分布式管理结构的企业，EBR通过VET接口使用链路本地多播名称解析（LLMNR）[RFC4795]解析“PRLNAME”。在这种情况下，PRL中的所有EBG响应LLMNR查询，EBR接受所有响应的并集。
Each distinct enterprise must have a unique identity that EBRs can use to uniquely discern their enterprise affiliations. 'PRLNAME' as well as the RLOCs of EBGs and the IP prefixes they aggregate serve as an identifier for the enterprise.
每个不同的企业必须有一个唯一的身份，EBR可以使用该身份来唯一地识别其企业从属关系。”PRLNAME’以及EBG的RLOC和它们聚合的IP前缀用作企业的标识符。
After EBG discovery, the EBR configures EIDs on its VET interfaces. When IPv6 and IPv4 are used as the inner/outer protocols (respectively), the EBR autoconfigures EIDs as specified in Section 5.4.1. In particular, the EBR acts as a host on its VET interfaces for router and prefix discovery purposes but acts as a router on its VET interfaces for routing protocol operation and packet forwarding purposes.
EBG发现后，EBR在其VET接口上配置EID。当IPv6和IPv4分别用作内部/外部协议时，EBR将按照第5.4.1节的规定自动配置EID。特别是，EBR在其VET接口上充当主机，用于路由器和前缀发现，但在其VET接口上充当路由器，用于路由协议操作和数据包转发。
EID configuration for other inner/outer IP protocol combinations is through administrative configuration or through an unspecified alternate method; in some cases, such EID configuration can be performed independently of EBG discovery.
其他内部/外部IP协议组合的EID配置通过管理配置或未指定的替代方法进行；在某些情况下，可以独立于EBG发现来执行此类EID配置。
EBRs can acquire Provider-Aggregated (PA) EID prefixes through autoconfiguration exchanges with EBGs over VET interfaces, where each EBG may be configured as either a DHCP relay or DHCP server.
EBR可以通过VET接口与EBG进行自动配置交换来获取提供商聚合（PA）EID前缀，其中每个EBG可以配置为DHCP中继或DHCP服务器。
For IPv4 EIDs, the EBR acquires prefixes via an automated IPv4 prefix delegation exchange, explicit management, etc.
对于IPv4 EID，EBR通过自动IPv4前缀委派交换、显式管理等获取前缀。
For IPv6 EIDs, the EBR acquires prefixes via DHCPv6 Prefix Delegation exchanges. In particular, the EBR (acting as a requesting router) can use DHCPv6 prefix delegation [RFC3633] over the VET interface to obtain IPv6 EID prefixes from the server (acting as a delegating router).
对于IPv6 EID，EBR通过DHCPv6前缀委派交换获取前缀。特别是，EBR（充当请求路由器）可以通过VET接口使用DHCPv6前缀委派[RFC3633]从服务器（充当委派路由器）获取IPv6 EID前缀。
The EBR obtains prefixes using either a 2-message or 4-message DHCPv6 exchange [RFC3315]. For example, to perform the 2-message exchange, the EBR's DHCPv6 client forwards a Solicit message with an IA_PD option to its DHCPv6 relay, i.e., the EBR acts as a combined client/ relay (see Section 4.1). The relay then forwards the message over the VET interface to an EBG, which either services the request or relays it further. The forwarded Solicit message will elicit a reply from the server containing PA IPv6 prefix delegations.
EBR使用2消息或4消息DHCPv6交换[RFC3315]获取前缀。例如，为了执行双消息交换，EBR的DHCPv6客户端将带有IA_PD选项的请求消息转发给其DHCPv6中继，即EBR充当组合客户端/中继（参见第4.1节）。然后，中继通过VET接口将消息转发给EBG，EBG为请求提供服务或进一步中继。转发的请求消息将从包含PA IPv6前缀委托的服务器获取答复。
The EBR can propose a specific prefix to the DHCPv6 server per Section 7 of [RFC3633], e.g., if a prefix delegation hint is available. The server will check the proposed prefix for consistency and uniqueness, then return it in the reply to the EBR if it was able to perform the delegation.
EBR可根据[RFC3633]第7节向DHCPv6服务器建议特定前缀，例如，如果前缀委派提示可用。服务器将检查建议的前缀的一致性和唯一性，如果能够执行委派，则在回复EBR时将其返回。
After the EBR receives PA prefix delegations, it can provision the prefixes on enterprise-edge interfaces as well as on other VET interfaces for which it is configured as an EBG. It can also provision the prefixes on enterprise-interior interfaces as long as other nodes on those interfaces unambiguously associate the prefixes with the EBR.
EBR收到PA前缀委托后，可以在企业边缘接口以及其他VET接口上提供前缀，并将其配置为EBG。它还可以在企业内部接口上提供前缀，只要这些接口上的其他节点明确地将前缀与EBR关联。
Independent of any PA prefixes, EBRs can acquire and use Provider-Independent (PI) EID prefixes that are self-configured (e.g., using [RFC4193], etc.) and/or delegated by a registration authority (e.g., using [CENTRL-ULA], etc.). When an EBR acquires a PI prefix, it must also obtain credentials that it can use to prove prefix ownership when it registers the prefixes with EBGs within an enterprise (see Sections 5.4 and 5.5).
独立于任何PA前缀，EBR可以获取和使用自配置（例如，使用[RFC4193]等）和/或由注册机构授权（例如，使用[CENTRL-ULA]等）的独立于提供商（PI）EID前缀。当EBR获得PI前缀时，还必须获得凭证，当EBR在企业内向EBGs注册前缀时，该凭证可用于证明前缀所有权（见第5.4和5.5节）。
After the EBR receives PI prefix delegations, it can provision the prefixes on enterprise-edge interfaces as well as on other VET interfaces for which it is configured as an EBG. It can also provision the prefixes on enterprise-interior interfaces as long as other nodes on those interfaces can unambiguously associate the prefixes with the EBR.
EBR收到PI前缀委托后，可以在企业边缘接口以及其他VET接口上提供前缀，并将其配置为EBG。它还可以在企业内部接口上提供前缀，只要这些接口上的其他节点可以明确地将前缀与EBR关联。
The minimum-sized IPv6 PI prefix that an EBR may acquire is a /56.
EBR可能获得的最小大小的IPv6 PI前缀是a/56。
The minimum-sized IPv4 PI prefix that an EBR may acquire is a /24.
EBR可能获得的最小大小的IPv4 PI前缀是a/24。
EBGs are EBRs that connect child enterprises to provider networks via provider-edge interfaces and/or via VET interfaces configured over parent enterprises. EBGs autoconfigure their provider-edge interfaces in a manner that is specific to the provider connections, and they autoconfigure their VET interfaces that were configured over parent enterprises, using the EBR autoconfiguration procedures specified in Section 4.2.
EBG是EBR，通过提供商边缘接口和/或通过在父企业上配置的VET接口将子企业连接到提供商网络。EBG以特定于提供商连接的方式自动配置其提供商边缘接口，并使用第4.2节中规定的EBR自动配置程序，自动配置通过母企业配置的VET接口。
For each of its VET interfaces configured over a child enterprise, the EBG initializes the interface and configures an EID the same as for an ordinary EBR (see Section 4.2.1). It must then arrange to add one or more of its RLOCs associated with the child enterprise to the PRL, and it must maintain these resource records in accordance with [RFC5214], Section 9. In particular, for each VET interface configured over a child enterprise, the EBG adds the RLOCs to name-service resource records for 'PRLNAME'.
对于通过子企业配置的每个VET接口，EBG将初始化接口并配置与普通EBR相同的EID（参见第4.2.1节）。然后必须安排将一个或多个与子企业相关的RLOC添加到PRL中，并且必须按照[RFC5214]第9节维护这些资源记录。特别是，对于在子企业上配置的每个VET接口，EBG将RLOCs添加到“PRLNAME”的服务资源记录名称中。
EBGs respond to LLMNR queries for 'PRLNAME' on VET interfaces configured over child enterprises with a distributed management structure.
EBG在通过分布式管理结构的子企业配置的VET接口上响应LLMNR对“PRLNAME”的查询。
EBGs configure a DHCP relay/server on VET interfaces configured over child enterprises that require DHCP services.
EBG在通过需要DHCP服务的子企业配置的VET接口上配置DHCP中继/服务器。
To avoid looping, EBGs must not configure a default route on a VET interface configured over a child interface.
为避免循环，EBGs不得在通过子接口配置的VET接口上配置默认路由。
Nodes that cannot be attached via an EBR's enterprise-edge interface (e.g., nomadic laptops that connect to a home office via a Virtual Private Network (VPN)) can instead be configured for operation as a simple host connected to the VET interface. Such VET hosts perform the same VET interface autoconfiguration procedures as specified for EBRs in Section 4.2.1, but they configure their VET interfaces as host interfaces (and not router interfaces). VET hosts can then send packets to the EID addresses of other hosts on the VET interface, or to off-enterprise EID destinations via a next-hop EBR.
不能通过EBR的企业边缘接口连接的节点（例如，通过虚拟专用网络（VPN）连接到家庭办公室的游牧笔记本电脑）可以配置为作为连接到VET接口的简单主机运行。此类VET主机执行第4.2.1节中为EBR规定的相同VET接口自动配置程序，但它们将其VET接口配置为主机接口（而不是路由器接口）。然后，VET主机可以将数据包发送到VET接口上其他主机的EID地址，或通过下一跳EBR发送到非企业EID目的地。
Note that a node may be configured as a host on some VET interfaces and as an EBR/EBG on other VET interfaces.
注意，节点可以在某些VET接口上配置为主机，在其他VET接口上配置为EBR/EBG。
Following the autoconfiguration procedures specified in Section 4, ERs, EBRs, EBGs, and VET hosts engage in normal internetworking operations as discussed in the following sections.
按照第4节中规定的自动配置程序，ERs、EBRs、EBGs和VET主机参与正常的网络互连操作，如下节所述。
Following autoconfiguration, ERs engage in any RLOC-based IP routing protocols and forward IP packets with RLOC addresses. EBRs can additionally engage in any EID-based IP routing protocols and forward IP packets with EID addresses. Note that the EID-based IP routing domains are separate and distinct from any RLOC-based IP routing domains.
在自动配置之后，ER参与任何基于RLOC的IP路由协议，并使用RLOC地址转发IP数据包。EBRs还可以参与任何基于EID的IP路由协议，并使用EID地址转发IP数据包。请注意，基于EID的IP路由域与任何基于RLOC的IP路由域是分开的。
When permitted by policy and supported by routing, end systems can avoid VET interface encapsulation through communications that directly invoke the outer IP protocol using RLOC addresses instead of EID addresses. End systems can use source address selection rules to determine whether to use EID or RLOC addresses based on, e.g., name-service records.
在策略允许和路由支持的情况下，终端系统可以通过使用RLOC地址而不是EID地址直接调用外部IP协议的通信来避免VET接口封装。终端系统可以使用源地址选择规则，根据例如名称服务记录来确定是否使用EID或RLOC地址。
In many enterprise scenarios, the use of EID-based communications (i.e., instead of RLOC-based communications) may be necessary and/or beneficial to support address scaling, NAT avoidance, security domain separation, site multihoming, traffic engineering, etc.
在许多企业场景中，使用基于EID的通信（即代替基于RLOC的通信）对于支持地址缩放、NAT避免、安全域分离、站点多宿主、流量工程等可能是必要和/或有益的。
The remainder of this section discusses internetworking operation for EID-based communications using the VET interface abstraction.
本节的其余部分将使用VET接口抽象讨论基于EID的通信的网络互连操作。
The following sections discuss router and prefix discovery considerations for the case of IPv6 as the inner IP protocol.
以下各节将讨论作为内部IP协议的IPv6情况下的路由器和前缀发现注意事项。
EBGs follow the router and prefix discovery procedures specified in [RFC5214], Section 8.2. They send solicited RAs over VET interfaces for which they are configured as gateways with default router lifetimes, with PIOs that contain PA prefixes for SLAAC, and with any other required options/parameters. The RAs can also include PIOs with the 'L' bit set to 0 and with a prefix such as '2001: DB8::/48'
EBG遵循[RFC5214]第8.2节中规定的路由器和前缀发现程序。它们通过VET接口发送请求的RAs，并将其配置为具有默认路由器生存期的网关、包含SLAAC PA前缀的PIO以及任何其他必需的选项/参数。RAs还可以包括“L”位设置为0且前缀为“2001:DB8:：/48”的PIO
as a hint of an aggregated prefix from which the EBG is willing to delegate longer PA prefixes. When PIOs that contain PA prefixes for SLAAC are included, the 'M' flag in the RA should also be set to 0.
作为聚合前缀的提示，EBG愿意从中委派更长的PA前缀。当包含SLAAC PA前缀的PIO时，RA中的“M”标志也应设置为0。
VET nodes follow the router and prefix discovery procedures specified in [RFC5214], Section 8.3. They discover EBGs within the enterprise as specified in Section 4.2.1.2, then perform RS/RA exchanges with the EBGs to establish and maintain default routes. In particular, the VET node sends unicast RS messages to EBGs over its VET interface(s) to receive RAs. Depending on the enterprise network trust basis, VET nodes may be required to use SEND to secure the RS/RA exchanges.
VET节点遵循[RFC5214]第8.3节中规定的路由器和前缀发现程序。他们按照第4.2.1.2节的规定在企业内发现EBG，然后与EBG进行RS/RA交换，以建立和维护默认路由。具体而言，VET节点通过其VET接口向EBGs发送单播RS消息以接收RAs。根据企业网络信任基础，VET节点可能需要使用SEND来保护RS/RA交换。
When the VET node receives an RA, it authenticates the message, then configures a default route based on the Router Lifetime. If the RA contains Prefix Information Options (PIOs) with the 'A' and 'L' bits set to 1, the VET node also autoconfigures IPv6 addresses from the advertised prefixes using SLAAC and assigns them to the VET interface. Thereafter, the VET node accepts packets that are forwarded by EBGs for which it has current default routing information (i.e., ingress filtering is based on the default router trust relationship rather than a prefix-specific ingress filter entry).
当VET节点接收到RA时，它对消息进行身份验证，然后根据路由器生存期配置默认路由。如果RA包含前缀信息选项（PIO），且“A”和“L”位设置为1，则VET节点还使用SLAAC自动配置播发前缀的IPv6地址，并将其分配给VET接口。此后，VET节点接受由EBGs转发的、其具有当前默认路由信息的分组（即，入口过滤基于默认路由器信任关系，而不是前缀特定的入口过滤条目）。
In enterprises in which DHCPv6 is preferred, DHCPv6 exchanges between EBRs and EBGs may be sufficient to convey default router and prefix information. In that case, RS/RA exchanges may not be necessary.
在首选DHCPv6的企业中，EBR和EBG之间的DHCPv6交换可能足以传递默认路由器和前缀信息。在这种情况下，可能不需要RS/RA交换。
After an EBR discovers default routes, it can use DHCP prefix delegation to obtain PA prefixes via an EBG as specified in Section 4.2.2. The DHCP server ensures that the delegations are unique and that the EBG's router function will forward IP packets over the VET interface to the correct EBR. In particular, the EBG must register and track the PA prefixes that are delegated to each EBR.
EBR发现默认路由后，可以使用DHCP前缀委派，通过第4.2.2节规定的EBG获得PA前缀。DHCP服务器确保委托是唯一的，并且EBG的路由器功能将通过VET接口将IP数据包转发到正确的EBR。特别是，EBG必须注册并跟踪委派给每个EBR的PA前缀。
The PA prefix registrations remain active in the EBGs as long as the EBR continues to issue DHCP renewals over the VET interface before lease lifetimes expire. The lease lifetime also keeps the delegation state active even if communications between the EBR and DHCP server are disrupted for a period of time (e.g., due to an enterprise network partition) before being reestablished (e.g., due to an enterprise network merge).
只要EBR在租赁期限到期之前继续通过VET接口发布DHCP续订，PA前缀注册在EBGs中保持活动状态。即使在重新建立之前（例如，由于企业网络合并），EBR和DHCP服务器之间的通信中断一段时间（例如，由于企业网络分区），租约生存期也会使委派状态保持活动状态。
After an EBR discovers default routes, it must register its PI prefixes by sending RAs to a set of one or more EBGs with Route Information Options (RIOs) [RFC4191] that contain the EBR's PI prefixes. Each RA must include the RLOC of an EBG as the outer IP destination address and a link-local address assigned to the VET interface as the inner IP destination address. For enterprises that use SEND, the RAs also include a CGA link-local inner source address, SEND credentials, plus any certificates needed to prove ownership of the PI prefixes. The EBR additionally tracks the set of EBGs to which it sends RAs so that it can send subsequent RAs to the same set.
EBR发现默认路由后，必须通过向包含EBR PI前缀的路由信息选项（RIO）[RFC4191]的一组或多个EBG发送RAs来注册其PI前缀。每个RA必须包括EBG的RLOC作为外部IP目标地址，以及分配给VET接口的链路本地地址作为内部IP目标地址。对于使用SEND的企业，RAs还包括CGA链接本地内部源地址、SEND凭证，以及证明PI前缀所有权所需的任何证书。EBR还跟踪向其发送RAs的EBG集，以便可以向同一集合发送后续RAs。
When the EBG receives the RA, it first authenticates the message; if the authentication fails, the EBG discards the RA. Otherwise, the EBG installs the PI prefixes with their respective lifetimes in its Forwarding Information Base (FIB) and configures them for both ingress filtering [RFC3704] and forwarding purposes. In particular, the EBG configures the FIB entries as ingress filter rules to accept packets received on the VET interface that have a source address taken from the PI prefixes. It also configures the FIB entries to forward packets received on other interfaces with a destination address taken from the PI prefixes to the EBR that registered the prefixes on the VET interface.
当EBG接收到RA时，它首先认证消息；如果身份验证失败，EBG将丢弃RA。否则，EBG在其转发信息库（FIB）中安装PI前缀及其各自的生存期，并将其配置为入口过滤[RFC3704]和转发目的。特别是，EBG将FIB条目配置为入口过滤器规则，以接受VET接口上接收的数据包，这些数据包的源地址取自PI前缀。它还将FIB条目配置为将在其他接口上接收的数据包转发到在VET接口上注册前缀的EBR，这些数据包的目标地址取自PI前缀。
The EBG then publishes the PI prefixes in a distributed database (e.g., in a private instance of a routing protocol in which only EBGs participate, via an automated name-service update mechanism [RFC3007], etc.). For enterprises that are managed under a centralized administrative authority, the EBG also publishes the PI prefixes in the enterprise-local name-service (e.g., the enterprise-local DNS [RFC1035]).
然后，EBG在分布式数据库中发布PI前缀（例如，在只有EBG参与的路由协议的私有实例中，通过自动名称服务更新机制[RFC3007]等）。对于在集中管理机构下管理的企业，EBG还将PI前缀发布在企业本地名称服务中（例如，企业本地DNS[RFC1035]）。
In particular, the EBG publishes each /56 prefix taken from the PI prefixes as a separate Fully Qualified Domain Name (FQDN) that consists of a sequence of 14 nibbles in reverse order (i.e., the same as in [RFC3596], Section 2.5) followed by the string 'ip6' followed by the string 'PRLNAME'. For example, when 'PRLNAME' is "isatap.example.com", the EBG publishes the prefix '2001:DB8::/56' as:
特别是，EBG将取自PI前缀的每个/56前缀发布为单独的完全限定域名（FQDN），该域名由14个半字节组成，顺序相反（即与[RFC3596]第2.5节中的相同），后跟字符串“ip6”，后跟字符串“PRLNAME”。例如，当“PRLNAME”为“isatap.example.com”时，EBG将前缀“2001:DB8:：/56”发布为：
'0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.isatap.example.com'.
“0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.isatap.example.com”。
The EBG includes the outer RLOC source address of the RA (e.g., in a DNS A resource record) in each prefix publication. For enterprises that use SEND, the EBG also includes the inner IPv6 CGA source address (e.g., in a DNS AAAA record) in each prefix publication. If
EBG在每个前缀发布中包括RA的外部RLOC源地址（例如，在DNS a资源记录中）。对于使用SEND的企业，EBG还包括每个前缀发布中的内部IPv6 CGA源地址（例如，在DNS AAAA记录中）。如果
the prefix was already installed in the distributed database, the EBG instead adds the outer RLOC source address (e.g., in an additional DNS A record) to the preexisting publication to support PI prefixes that are multihomed. For enterprises that use SEND, this latter provision requires all EBRs of a multihomed site that advertise the same PI prefixes in RAs to use the same CGA and the same SEND credentials.
前缀已安装在分布式数据库中，EBG将外部RLOC源地址（例如，在附加DNS A记录中）添加到先前存在的发布中，以支持多址PI前缀。对于使用SEND的企业，后一项规定要求在RAs中公布相同PI前缀的多址站点的所有EBR使用相同的CGA和相同的SEND凭据。
After the EBG authenticates the RA and publishes the PI prefixes, it next acts as a Neighbor Discovery proxy (NDProxy) [RFC4389] on the VET interfaces configured over any of its parent enterprises, and it relays a proxied RA to the EBGs on those interfaces. (For enterprises that use SEND, the EBG additionally acts as a SEcure Neighbor Discovery Proxy (SENDProxy) [SEND-PROXY].) EBGs in parent enterprises that receive the proxied RAs in turn act as NDProxys/SENDProxys to relay the RAs to EBGs on their parent enterprises, etc. The RA proxying and PI prefix publication recurses in this fashion and ends when an EBR attached to an interdomain routing core is reached.
EBG对RA进行身份验证并发布PI前缀后，接下来在其任何父企业上配置的VET接口上充当邻居发现代理（NDProxy）[RFC4389]，并将代理RA中继到这些接口上的EBG。（对于使用SEND的企业，EBG还充当安全邻居发现代理（SENDProxy）[SEND-Proxy]）。接收代理RAs的母企业中的EBG依次充当NDProxys/SENDProxys，将RAs中继到其母企业上的EBG，等。RA代理和PI前缀发布以这种方式递归，并在到达连接到域间路由核心的EBR时结束。
After the initial PI prefix registration, the EBR that owns the prefix(es) must periodically send additional RAs to its set of EBGs to refresh prefix lifetimes. Each such EBG tracks the set of EBGs in parent enterprises to which it relays the proxied RAs, and should relay subsequent RAs to the same set.
初始PI前缀注册后，拥有前缀的EBR必须定期向其EBG集发送额外的RAs以刷新前缀生存期。每个这样的EBG跟踪其将代理RAs中继到的母企业中的EBG集合，并且应该将后续RAs中继到同一集合。
This procedure has a direct analogy in the Teredo method of maintaining state in network middleboxes through the periodic transmission of "bubbles" [RFC4380].
该程序与Teredo方法直接类似，Teredo方法通过定期传输“气泡”来维持网络中间盒的状态[RFC4380]。
VET nodes discover destination-specific next-hop EBRs within the enterprise by querying the name service for the /56 IPv6 PI prefix taken from a packet's destination address, by forwarding packets via a default route to an EBG, or by some other inner-IP-to-outer-IP address mapping mechanism. For example, for the IPv6 destination address '2001:DB8:1:2::1' and 'PRLNAME' "isatap.example.com" the VET node can lookup the domain name:
VET节点通过查询从数据包目的地地址获取的/56 IPv6 PI前缀的名称服务，通过将数据包通过默认路由转发到EBG，或通过某种其他内部IP到外部IP地址映射机制，在企业内发现特定于目的地的下一跳EBR。例如，对于IPv6目标地址“2001:DB8:1:2:：1”和“PRLNAME”isatap.example.com”，VET节点可以查找域名：
'0.0.1.0.0.0.8.b.d.0.1.0.0.2.ip6.isatap.example.com'.
“0.0.1.0.0.0.8.b.d.0.1.0.0.2.ip6.isatap.example.com”。
If the name-service lookup succeeds, it will return RLOC addresses (e.g., in DNS A records) that correspond to next-hop EBRs to which the VET node can forward packets. (In enterprises that use SEND, it will also return an IPv6 CGA address, e.g., in a DNS AAAA record.)
如果名称服务查找成功，它将返回对应于VET节点可以转发数据包的下一跳EBR的RLOC地址（例如，在DNS A记录中）。（在使用SEND的企业中，它还将返回IPv6 CGA地址，例如在DNS AAAA记录中。）
Name-service lookups in enterprises with a centralized management structure use an infrastructure-based service, e.g., an enterprise-local DNS. Name-service lookups in enterprises with a distributed management structure and/or that lack an infrastructure-based name-service instead use LLMNR over the VET interface. When LLMNR is used, the EBR that performs the lookup sends an LLMNR query (with the /56 prefix taken from the IP destination address encoded in dotted-nibble format as shown above) and accepts the union of all replies it receives from other EBRs on the VET interface. When an EBR receives an LLMNR query, it responds to the query IFF it aggregates an IP prefix that covers the prefix in the query.
在具有集中管理结构的企业中，名称服务查找使用基于基础结构的服务，例如，企业本地DNS。在具有分布式管理结构和/或缺少基于基础设施的名称服务的企业中，名称服务查找将通过VET接口使用LLMNR。当使用LLMNR时，执行查找的EBR发送一个LLMNR查询（其中/56前缀取自以点半字节格式编码的IP目标地址，如上所示），并接受VET接口上从其他EBR接收的所有回复的联合。当EBR收到LLMNR查询时，如果它聚合了一个覆盖查询中前缀的IP前缀，它将响应查询。
Alternatively, in enterprises with a stable and highly-available set of EBGs, the VET node can simply forward an initial packet via a default route to an EBG. The EBG will forward the packet to a next-hop EBR on the VET interface and return an ICMPv6 Redirect [RFC4861] (using SEND, if necessary). If the packet's source address is on-link on the VET interface, the EBG returns an ordinary "router-to-host" redirect with the source address of the packet as its destination. If the packet's source address is not on-link, the EBG instead returns a "router-to-router" redirect with the link-local ISATAP address of the previous-hop EBR as its destination. When IPv4 is used as the outer IP protocol, the EBG also includes in the redirect one or more IPv6 Link-Layer Address Options (LLAOs) that contain the IPv4 RLOCs of potential next-hop EBRs arranged in order from lowest to highest priority (i.e., the first LLAO contains the lowest priority RLOC and the final LLAO option contains the highest priority). These LLAOs are formatted using a modified version of the form specified in Section 5 of [RFC2529], as shown in Figure 2 (the LLAO format for IPv6 as the outer IP protocol is out of scope).
或者，在具有一组稳定且高度可用的EBG的企业中，VET节点可以简单地经由默认路由将初始分组转发到EBG。EBG将数据包转发到VET接口上的下一跳EBR，并返回ICMPv6重定向[RFC4861]（必要时使用SEND）。如果数据包的源地址在VET接口的链路上，EBG返回一个普通的“路由器到主机”重定向，数据包的源地址作为其目的地。如果数据包的源地址不在链路上，EBG将返回一个“路由器到路由器”重定向，并将前一跳EBR的链路本地ISATAP地址作为其目的地。当IPv4用作外部IP协议时，EBG还在重定向中包括一个或多个IPv6链路层地址选项（LLAO），其中包含按从最低到最高优先级排列的潜在下一跳EBR的IPv4 RLOC（即，第一个LLAO包含最低优先级的RLOC，最后一个LLAO选项包含最高优先级）。这些LLAO使用[RFC2529]第5节中规定格式的修改版本进行格式化，如图2所示（作为外部IP协议的IPv6的LLAO格式超出范围）。
+-------+-------+-------+-------+-------+-------+-------+-------+
| Type |Length | TTL | IPv4 Address |
+-------+-------+-------+-------+-------+-------+-------+-------+
+-------+-------+-------+-------+-------+-------+-------+-------+
| Type |Length | TTL | IPv4 Address |
+-------+-------+-------+-------+-------+-------+-------+-------+
Figure 2: VET Link-Layer Address Option Format
图2:VET链路层地址选项格式
For each such IPv6/IPv4 LLAO, the Type is set to 2 (for Target Link-Layer Address Option), Length is set to 1, and IPv4 Address is set to the IPv4 RLOC of the next-hop EBR. TTL is set to the time in seconds that the recipient may cache the RLOC, where the value 65535 represents infinity and the value 0 suspends forwarding through this RLOC.
对于每个这样的IPv6/IPv4 LLAO，类型设置为2（对于目标链路层地址选项），长度设置为1，IPv4地址设置为下一跳EBR的IPv4 RLOC。TTL设置为收件人可以缓存RLOC的时间（以秒为单位），其中值65535表示无穷大，值0暂停通过该RLOC的转发。
When a VET host receives an ordinary "router-to-host" redirect, it processes the redirect exactly as specified in [RFC4861], Section 8. When an EBR receives a "router-to-router" redirect, it discovers the RLOC addresses of potential next-hop EBRs by examining the LLAOs
当VET主机收到普通的“路由器到主机”重定向时，它将按照[RFC4861]第8节的规定处理重定向。当EBR收到“路由器到路由器”重定向时，它通过检查LLAO发现潜在下一跳EBR的RLOC地址
included in the redirect. The EBR then installs a FIB entry that contains the /56 prefix of the destination address encoded in the redirect and the list of RLOCs of potential next-hop EBRs. The EBR then enables the FIB entry for forwarding to next-hop EBRs but DOES NOT enable it for ingress filtering acceptance of packets from next-hop EBRs (i.e., the forwarding determination is unidirectional).
包括在重定向中。然后，EBR安装一个FIB条目，该条目包含重定向中编码的目标地址的/56前缀和潜在下一跳EBR的RLOC列表。然后，EBR启用FIB条目以转发到下一跳EBR，但不启用它以对来自下一跳EBR的数据包进行入口过滤接受（即，转发确定是单向的）。
In enterprises in which spoofing is possible, after discovering potential next-hop EBRs (either through name-service lookup or ICMP redirect) the EBR must send authenticating credentials before forwarding packets via the next-hops. To do so, the EBR must send RAs over the VET interface (using SEND, if necessary) to one or more of the potential next-hop EBRs with an RLOC as the outer IP destination address. The RAs must include a Route Information Option (RIO) [RFC4191] that contains the /56 PI prefix of the original packet's source address. After sending the RAs, the EBR can either enable the new FIB entry for forwarding immediately or delay until it receives an explicit acknowledgement that a next-hop EBR received the RA (e.g., using the SEAL explicit acknowledgement mechanism -- see Section 5.7).
在可能进行欺骗的企业中，在发现潜在的下一跳EBR（通过名称服务查找或ICMP重定向）后，EBR必须在通过下一跳转发数据包之前发送身份验证凭据。为此，EBR必须通过VET接口（如有必要，使用send）将RAs发送到一个或多个具有RLOC作为外部IP目标地址的潜在下一跳EBR。RAs必须包括路由信息选项（RIO）[RFC4191]，该选项包含原始数据包源地址的/56 PI前缀。发送RAs后，EBR可以立即启用新的FIB条目进行转发，也可以延迟直到收到下一跳EBR接收到RA的明确确认（例如，使用SEAL明确确认机制——参见第5.7节）。
When a next-hop EBR receives the RA, it authenticates the message then it performs a name-service lookup on the prefix in the RIO if further authenticating evidence is required. If the name service returns resource records that are consistent with the inner and outer IP addresses of the RA, the next-hop EBR then installs the prefix in the RIO in its FIB and enables the FIB entry for ingress filtering but DOES NOT enable it for forwarding purposes. After an EBR sends initial RAs following a redirect, it should send periodic RAs to refresh the next-hop EBR's ingress filter prefix lifetimes as long as traffic is flowing.
当下一跳EBR接收到RA时，它会对消息进行身份验证，然后如果需要进一步的身份验证证据，它会对RIO中的前缀执行名称服务查找。如果名称服务返回的资源记录与RA的内部和外部IP地址一致，则下一跳EBR将在其FIB的RIO中安装前缀，并启用FIB条目进行入口过滤，但不启用它进行转发。EBR在重定向后发送初始RAs后，应定期发送RAs以刷新下一跳EBR的入口过滤器前缀寿命，只要流量在流动。
EBRs retain the FIB entries created as a result of an ICMP redirect until all RLOC TTLs expire, or until no hints of forward progress through any of the associated RLOCs are received. In this way, RLOC liveness detection exactly parallels IPv6 Neighbor Unreachability Detection ([RFC4861], Section 3).
EBR保留因ICMP重定向而创建的FIB条目，直到所有RLOC TTL过期，或者直到没有收到通过任何相关RLOC的前进提示。通过这种方式，RLOC活动性检测与IPv6邻居不可达性检测完全平行（[RFC4861]，第3节）。
When IPv4 is used as the inner IP protocol, router discovery and prefix registration exactly parallel the mechanisms specified for IPv6 in Section 5.4. To support this, modifications to the ICMPv4 Router Advertisement [RFC1256] function to include SEND constructs and modifications to the ICMPv4 Redirect [RFC0792] function to support router-to-router redirects will be specified in a future
当IPv4用作内部IP协议时，路由器发现和前缀注册与第5.4节中为IPv6指定的机制完全并行。为了支持这一点，将来将指定对ICMPv4路由器公告[RFC1256]功能的修改，以包括发送构造，以及对ICMPv4重定向[RFC0792]功能的修改，以支持路由器到路由器的重定向
document. Additionally, publications for IPv4 prefixes will be in dotted-nibble format in the 'ip4.isatap.example.com' domain. For example, the IPv4 prefix 192.0.2/24 would be represented as:
文件此外，IPv4前缀的发布将在“ip4.isatap.example.com”域中采用点半字节格式。例如，IPv4前缀192.0.2/24将表示为：
'2.0.0.0.0.c.ip4.isatap.example.com'
“2.0.0.0.0.c.ip4.isatap.example.com”
VET nodes forward packets by consulting the FIB to determine a specific EBR/EBG as the next-hop router on a VET interface. When multiple next-hop routers are available, VET nodes can use default router preferences, routing protocol information, traffic engineering configurations, etc. to select the best exit router. When there is no FIB information other than "default" available, VET nodes can discover the next-hop EBR/EBG through the mechanisms specified in Section 5.4 and Section 5.5.
VET节点通过咨询FIB来转发数据包，以确定特定EBR/EBG作为VET接口上的下一跳路由器。当多个下一跳路由器可用时，VET节点可以使用默认路由器首选项、路由协议信息、流量工程配置等来选择最佳退出路由器。当没有除“默认”之外的FIB信息可用时，VET节点可以通过第5.4节和第5.5节中指定的机制发现下一跳EBR/EBG。
VET interfaces encapsulate inner IP packets in any mid-layer headers followed by an outer IP header according to the specific encapsulation type (e.g., [RFC4301], [RFC5214], [RFC5320], etc.); they next submit the encapsulated packet to the outer IP forwarding engine for transmission on an underlying interface.
VET接口根据特定的封装类型（例如，[RFC4301]、[RFC5214]、[RFC5320]等）将内部IP数据包封装在任何中间层报头中，然后是外部IP报头；然后，他们将封装的数据包提交给外部IP转发引擎，以便在底层接口上进行传输。
For forwarding to next-hop addresses over VET interfaces that use IPv6-in-IPv4 encapsulation, VET nodes determine the outer destination address (i.e., the IPv4 RLOC of the next-hop EBR) through static extraction of the IPv4 address embedded in the next-hop ISATAP address. For other IP-in-IP encapsulations, determination of the outer destination address is through administrative configuration or through an unspecified alternate method. When there are multiple candidate destination RLOCs available, the VET node should only select an RLOC for which there is current forwarding information in the outer IP protocol FIB.
为了通过使用IPv6-in-IPv4封装的VET接口转发到下一跳地址，VET节点通过静态提取嵌入到下一跳ISATAP地址中的IPv4地址来确定外部目标地址（即，下一跳EBR的IPv4 RLOC）。对于其他IP-in-IP封装，通过管理配置或未指定的替代方法确定外部目标地址。当有多个候选目的地RLOC可用时，VET节点应仅选择外部IP协议FIB中存在当前转发信息的RLOC。
VET nodes should use SEAL encapsulation [RFC5320] over VET interfaces to accommodate path MTU diversity, to defeat source address spoofing, and to monitor next-hop EBR reachability. SEAL encapsulation maintains a unidirectional and monotonically incrementing per-packet identification value known as the 'SEAL_ID'. When a VET node that uses SEAL encapsulation sends a SEND-protected Router Advertisement (RA) or Router Solicitation (RS) message to another VET node, both nodes cache the new SEAL_ID as per-tunnel state used for maintaining a window of unacknowledged SEAL_IDs.
VET节点应在VET接口上使用密封封装[RFC5320]，以适应路径MTU多样性，防止源地址欺骗，并监控下一跳EBR的可达性。密封封装保持一个单向且单调递增的每个数据包标识值，称为“密封ID”。当使用密封封装的VET节点向另一个VET节点发送发送受保护的路由器广告（RA）或路由器请求（RS）消息时，两个节点根据用于维护未确认的密封ID窗口的隧道状态缓存新的密封ID。
In terms of security, when a VET node receives an ICMP message, it can confirm that the packet-in-error within the ICMP message corresponds to one of its recently sent packets by examining the SEAL_ID along with source and destination addresses, etc. Additionally, a next-hop EBR can track the SEAL_ID in packets received from EBRs for which there is an ingress filter entry and discard packets that have SEAL_ID values outside of the current window.
在安全性方面，当VET节点接收到ICMP消息时，它可以通过检查封条ID以及源地址和目的地地址等来确认ICMP消息中出错的数据包对应于其最近发送的数据包之一。此外，下一跳EBR可以跟踪从EBR接收的数据包中的SEAL_ID，其中存在入口过滤器条目，并丢弃当前窗口之外具有SEAL_ID值的数据包。
In terms of next-hop reachability, an EBR can set the SEAL "Acknowledgement Requested" bit in messages to receive confirmation that a next-hop EBR is reachable. Setting the "Acknowledgement Requested" bit is also used as the method for maintaining the window of outstanding SEAL_IDs.
就下一跳可达性而言，EBR可以在消息中设置SEAL“acknowledge Requested”位，以接收下一跳EBR可达性的确认。设置“确认请求”位也用作维护未完成印章ID窗口的方法。
When an EBR receives an IPv6 packet over a VET interface and there is no matching ingress filter entry, it drops the packet and returns an ICMPv6 [RFC4443] "Destination Unreachable; Source address failed ingress/egress policy" message to the previous-hop EBR subject to rate limiting.
当EBR通过VET接口接收到IPv6数据包且没有匹配的入口过滤器条目时，EBR会丢弃该数据包并将ICMPv6[RFC4443]“目的地不可访问；源地址失败的入口/出口策略”消息返回给前一跳EBR（受速率限制）。
When an EBR receives an IPv6 packet over a VET interface, and there is no longest-prefix-match FIB entry for the destination, it returns an ICMPv6 "Destination Unreachable; No route to destination" message to the previous hop EBR subject to rate limiting.
当EBR通过VET接口接收到IPv6数据包，且目的地没有最长前缀匹配FIB条目时，它会向受速率限制的前一跳EBR返回ICMPv6“目的地不可访问；无路由到目的地”消息。
When an EBR receives an IPv6 packet over a VET interface and the longest-prefix-match FIB entry for the destination is via a next-hop configured over the same VET interface the packet arrived on, the EBR forwards the packet, then (if the FIB prefix is longer than ::/0) sends a router-to-router ICMPv6 Redirect message (using SEND, if necessary) to the previous-hop EBR as specified in Section 5.4.4.
当EBR通过VET接口接收到IPv6数据包，且目的地的最长前缀匹配FIB条目是通过数据包到达的同一VET接口上配置的下一跳进行的，EBR转发数据包，然后（如果FIB前缀长于：：/0）向路由器发送一条ICMPv6重定向消息（必要时使用SEND）按照第5.4.4节的规定，连接到上一跳EBR。
Generation of other ICMP messages [RFC0792] [RFC4443] is the same as for any IP interface.
其他ICMP消息[RFC0792][RFC4443]的生成与任何IP接口相同。
When an EBR receives an ICMPv6 "Destination Unreachable; Source address failed ingress/egress policy" message from a next-hop EBR, and there is a longest-prefix-match FIB entry for the original packet's destination that is more specific than ::/0, the EBR discards the message and marks the FIB entry for the destination as "forwarding suspended" for the RLOC taken from the source address of the ICMPv6 message. The EBR should then allow subsequent packets to flow through different RLOCs associated with the FIB entry until it
当EBR从下一跳EBR接收到ICMPv6“目的地不可访问；源地址失败的入口/出口策略”消息，并且原始数据包的目的地有一个最长的前缀匹配FIB条目，该条目比：：/0更具体时，EBR丢弃该消息并将目的地的FIB条目标记为“转发已暂停”用于从ICMPv6消息的源地址获取的RLOC。然后，EBR应允许后续数据包流经与FIB条目相关联的不同RLOC，直到
forwards a new RA to the suspended RLOC. If the EBR receives excessive ICMPv6 ingress/egress policy errors through multiple RLOCs associated with the same FIB entry, it should delete the FIB entry and allow subsequent packets to flow through an EBG if supported in the specific enterprise scenario.
将新RA转发给挂起的RLOC。如果EBR通过与同一FIB条目关联的多个RLOC接收到过多的ICMPv6入口/出口策略错误，则应删除FIB条目，并允许后续数据包流经EBG（如果特定企业场景中支持）。
When a VET node receives an ICMPv6 "Destination Unreachable; No route to destination" message from a next-hop EBR, it forwards the ICMPv6 message to the source of the original packet as normal. If the EBR has longest-prefix-match FIB entry for the original packet's destination that is more specific than ::/0, the EBR also deletes the FIB entry.
当VET节点从下一跳EBR接收到ICMPv6“无法到达目的地；没有到目的地的路由”消息时，它会正常地将ICMPv6消息转发到原始数据包的源。如果EBR的原始数据包目的地的最长前缀匹配FIB条目比：：/0更具体，则EBR也会删除FIB条目。
When an EBR receives an authentic ICMPv6 Redirect, it processes the packet as specified in Section 5.4.4.
当EBR接收到真实的ICMPv6重定向时，它将按照第5.4.4节的规定处理数据包。
When an EBG receives new mapping information for a specific destination prefix, it can propagate the update to other EBRs/EBGs by sending an ICMPv6 redirect message to the 'All Routers' link-local multicast address with an LLAO with the TTL for the unreachable LLAO set to zero, and with a NULL packet in error.
当EBG接收到特定目的地前缀的新映射信息时，它可以通过向“所有路由器”链路本地多播地址发送ICMPv6重定向消息，将更新传播到其他EBR/EBG，其中LLAO的TTL设置为零，不可访问LLAO的TTL设置为零，并且错误的数据包为空。
Additionally, a VET node may receive ICMP "Destination Unreachable; net / host unreachable" messages from an ER indicating that the path to a VET neighbor may be failing. The VET node should first check, e.g., the SEAL_ID, IPsec sequence number, source address of the original packet if available, etc. to obtain reasonable assurance that the ICMP message is authentic, then should mark the longest-prefix-match FIB entry for the destination as "forwarding suspended" for the RLOC destination address of the ICMP packet-in-error. If the VET node receives excessive ICMP unreachable errors through multiple RLOCs associated with the same FIB entry, it should delete the FIB entry and allow subsequent packets to flow through a different route.
此外，VET节点可以从ER接收ICMP“目的地不可访问；网络/主机不可访问”消息，指示到VET邻居的路径可能失败。VET节点应首先检查封条ID、IPsec序列号、原始数据包的源地址（如果可用）等，以获得ICMP消息真实性的合理保证，然后应将目标的最长前缀匹配FIB条目标记为“转发暂停”错误的ICMP数据包的RLOC目标地址。如果VET节点通过与同一FIB条目相关联的多个RLOC接收到过多的ICMP不可到达错误，则它应删除FIB条目，并允许后续数据包通过不同的路由。
EBRs that travel between distinct enterprise networks must either abandon their PA prefixes that are relative to the "old" enterprise and obtain new ones relative to the "new" enterprise or somehow coordinate with a "home" enterprise to retain ownership of the prefixes. In the first instance, the EBR would be required to coordinate a network renumbering event using the new PA prefixes [RFC4192]. In the second instance, an ancillary mobility management mechanism must be used.
在不同企业网络之间移动的EBR必须放弃其相对于“旧”企业的PA前缀，获得相对于“新”企业的新前缀，或者以某种方式与“主”企业协调以保留前缀的所有权。在第一种情况下，EBR需要使用新的PA前缀协调网络重新编号事件[RFC4192]。在第二种情况下，必须使用辅助移动管理机制。
EBRs can retain their PI prefixes as they travel between distinct enterprise networks as long as they register the prefixes with new EBGs and (preferably) withdraw the prefixes from old EBGs prior to
EBR可以在不同的企业网络之间移动时保留其PI前缀，只要它们向新EBG注册前缀，并且（最好）在迁移之前从旧EBG中提取前缀
departure. Prefix registration with new EBGs is coordinated exactly as specified in Section 5.4.3; prefix withdrawal from old EBGs is simply through re-announcing the PI prefixes with zero lifetimes.
离开与新EBG的前缀注册完全按照第5.4.3节的规定进行协调；从旧EBG中提取前缀只是通过重新宣布PI前缀的零生存期。
Since EBRs can move about independently of one another, stale FIB entry state may be left in VET nodes when a neighboring EBR departs. Additionally, EBRs can lose state for various reasons, e.g., power failure, machine reboot, etc. For this reason, EBRs are advised to set relatively short PI prefix lifetimes in RIO options, and to send additional RAs to refresh lifetimes before they expire. (EBRs should place conservative limits on the RAs they send to reduce congestion, however.)
由于EBR可以彼此独立地移动，当相邻EBR离开时，过时的FIB进入状态可能会留在VET节点中。此外，由于各种原因，EBR可能会失去状态，例如电源故障、机器重新启动等。因此，建议EBR在RIO选项中设置相对较短的PI前缀生存期，并在其到期之前发送额外的RAs以刷新生存期。（然而，欧洲复兴开发银行应该对其发送的RAs设置保守限制，以减少拥堵。）
EBRs may register their PI prefixes with multiple EBGs for multihoming purposes. EBRs should only forward packets via EBGs with which it has registered its PI prefixes, since other EBGs may drop the packets and return ICMPv6 "Destination Unreachable; Source address failed ingress/egress policy" messages.
EBR可将其PI前缀注册到多个EBG，以实现多归宿。EBR应仅通过已注册其PI前缀的EBG转发数据包，因为其他EBG可能会丢弃数据包并返回ICMPv6“目的地不可访问；源地址失败的入口/出口策略”消息。
EBRs can also act as delegating routers to sub-delegate portions of their PI prefixes to requesting routers on their enterprise-edge interfaces and on VET interfaces for which they are configured as EBGs. In this sense, the sub-delegations of an EBR's PI prefixes become the PA prefixes for downstream-dependent nodes. Downstream-dependent nodes that travel with a mobile provider EBR can continue to use addresses configured from PA prefixes; downstream-dependent nodes that move away from their provider EBR must perform address/ prefix renumbering when they associate with a new provider.
EBR还可以充当委托路由器，将其PI前缀的一部分再委托给其企业边缘接口和VET接口上的请求路由器，这些路由器被配置为EBG。在这个意义上，EBR的PI前缀的子委托成为下游依赖节点的PA前缀。与移动提供商EBR一起旅行的下游依赖节点可以继续使用从PA前缀配置的地址；从提供程序EBR移出的下游从属节点在与新提供程序关联时必须执行地址/前缀重新编号。
The EBGs of a multihomed enterprise should participate in a private inner IP routing protocol instance between themselves (possibly over an alternate topology) to accommodate enterprise partitions/merges as well as intra-enterprise mobility events. These peer EBGs should accept packets from one another without respect to the destination (i.e., ingress filtering is based on the peering relationship rather than a prefix-specific ingress filter entry).
多宿企业的EBG应参与它们之间的私有内部IP路由协议实例（可能通过备用拓扑），以适应企业分区/合并以及企业内移动事件。这些对等EBG应接受来自彼此的数据包，而不考虑目的地（即，入口过滤基于对等关系，而不是前缀特定的入口过滤条目）。
In multicast-capable deployments, ERs provide an enterprise-wide multicasting service (e.g., Simplified Multicast Forwarding (SMF) [MANET-SMF], Protocol Independent Multicast (PIM) routing, Distance Vector Multicast Routing Protocol (DVMRP) routing, etc.) over their enterprise-interior interfaces such that outer IP multicast messages of site-scope or greater scope will be propagated across the enterprise. For such deployments, VET nodes can also provide an inner IP multicast/broadcast capability over their VET interfaces through mapping of the inner IP multicast address space to the outer
在支持多播的部署中，ER提供企业范围的多播服务（例如，简化多播转发（SMF）[MANET-SMF]、协议独立多播（PIM）路由、距离向量多播路由协议（DVMRP）路由等）通过其企业内部接口，站点范围或更大范围的外部IP多播消息将在整个企业中传播。对于此类部署，VET节点还可以通过将内部IP多播地址空间映射到外部IP多播地址空间，通过其VET接口提供内部IP多播/广播功能
IP multicast address space. In that case, operation of link-scoped (or greater scoped) inner IP multicasting services (e.g., a link-scoped neighbor discovery protocol) over the VET interface is available, but link-scoped services should be used sparingly to minimize enterprise-wide flooding.
IP多播地址空间。在这种情况下，可以通过VET接口操作链路范围（或更大范围）的内部IP多播服务（例如，链路范围的邻居发现协议），但应谨慎使用链路范围的服务，以最小化企业范围的泛洪。
VET nodes encapsulate inner IP multicast messages sent over the VET interface in any mid-layer headers (e.g., IPsec, SEAL, etc.) plus an outer IP header with a site-scoped outer IP multicast address as the destination. For the case of IPv6 and IPv4 as the inner/outer protocols (respectively), [RFC2529] provides mappings from the IPv6 multicast address space to a site-scoped IPv4 multicast address space (for other IP-in-IP encapsulations, mappings are established through administrative configuration or through an unspecified alternate static mapping).
VET节点将通过VET接口发送的内部IP多播消息封装在任何中间层报头（如IPsec、SEAL等）中，再加上一个外部IP报头，其中一个站点范围的外部IP多播地址作为目标。对于将IPv6和IPv4分别作为内部/外部协议的情况，[RFC2529]提供从IPv6多播地址空间到站点范围的IPv4多播地址空间的映射（对于IP封装中的其他IP，通过管理配置或未指定的备用静态映射建立映射）。
Multicast mapping for inner IP multicast groups over outer IP multicast groups can be accommodated, e.g., through VET interface snooping of inner multicast group membership and routing protocol control messages. To support inner-to-outer IP multicast mapping, the VET interface acts as a virtual outer IP multicast host connected to its underlying interfaces. When the VET interface detects that an inner IP multicast group joins or leaves, it forwards corresponding outer IP multicast group membership reports on an underlying interface over which the VET interface is configured. If the VET node is configured as an outer IP multicast router on the underlying interfaces, the VET interface forwards locally looped-back group membership reports to the outer IP multicast routing process. If the VET node is configured as a simple outer IP multicast host, the VET interface instead forwards actual group membership reports (e.g., IGMP messages) directly over an underlying interface.
例如，通过内部多播组成员资格和路由协议控制消息的VET接口窥探，可以在外部IP多播组上容纳内部IP多播组的多播映射。为了支持内部到外部IP多播映射，VET接口充当连接到其底层接口的虚拟外部IP多播主机。当VET接口检测到内部IP多播组加入或离开时，它会在配置VET接口的基础接口上转发相应的外部IP多播组成员资格报告。如果VET节点配置为基础接口上的外部IP多播路由器，则VET接口将本地环回组成员资格报告转发给外部IP多播路由进程。如果将VET节点配置为简单的外部IP多播主机，则VET接口将直接通过底层接口转发实际的组成员报告（例如，IGMP消息）。
Since inner IP multicast groups are mapped to site-scoped outer IP multicast groups, the VET node must ensure that the site-scope outer IP multicast messages received on the underlying interfaces for one VET interface do not "leak out" to the underlying interfaces of another VET interface. This is accommodated through normal site-scoped outer IP multicast group filtering at enterprise boundaries.
由于内部IP多播组映射到站点范围的外部IP多播组，因此VET节点必须确保在一个VET接口的基础接口上接收的站点范围外部IP多播消息不会“泄漏”到另一个VET接口的基础接口。这是通过在企业边界进行正常的站点范围的外部IP多播组过滤来实现的。
VET nodes can perform enterprise-wide service discovery using a suitable name-to-address resolution service. Examples of flooding-based services include the use of LLMNR [RFC4795] over the VET
VET节点可以使用适当的名称来执行企业范围的服务发现，以解决解决服务问题。基于泛洪的服务示例包括在VET上使用LLMNR[RFC4795]
interface or multicast DNS [mDNS] over an underlying interface. More scalable and efficient service discovery mechanisms are for further study.
通过基础接口的接口或多播DNS[MDN]。更具可扩展性和效率的服务发现机制有待进一步研究。
EBGs can physically partition an enterprise by configuring multiple VET interfaces over multiple distinct sets of underlying interfaces. In that case, each partition (i.e., each VET interface) must configure its own distinct 'PRLNAME' (e.g., 'isatap.zone1.example.com', 'isatap.zone2.example.com', etc.).
EBG可以通过在多个不同的底层接口集上配置多个VET接口来对企业进行物理分区。在这种情况下，每个分区（即每个VET接口）必须配置自己独特的“PRLNAME”（例如，“isatap.zone1.example.com”、“isatap.zone2.example.com”等）。
EBGs can logically partition an enterprise using a single VET interface by sending RAs with PIOs containing different IPv6 PA prefixes to group nodes into different logical partitions. EBGs can identify partitions, e.g., by examining RLOC prefixes, observing the interfaces over which RSs are received, etc. In that case, a single 'PRLNAME' can cover all partitions.
EBG可以使用单个VET接口对企业进行逻辑分区，方法是向RAs发送包含不同IPv6 PA前缀的PIO，将节点分组到不同的逻辑分区中。EBG可以识别分区，例如，通过检查RLOC前缀、观察接收RSs的接口等。在这种情况下，单个“PRLNAME”可以覆盖所有分区。
EBGs must retain explicit state that tracks the inner IP prefixes owned by EBRs within the enterprise, e.g., so that packets are delivered to the correct EBRs and not incorrectly "leaked out" of the enterprise via a default route. For PA prefixes, the state is maintained via an EBR's DHCP prefix delegation lease renewals, while for PI prefixes the state is maintained via an EBR's periodic prefix registration RAs.
EBG必须保留跟踪企业内EBR拥有的内部IP前缀的明确状态，例如，这样数据包就可以传送到正确的EBR，而不会通过默认路由错误地“泄漏”出企业。对于PA前缀，状态通过EBR的DHCP前缀委派租约续订来维护，而对于PI前缀，状态通过EBR的定期前缀注册RAs来维护。
When an EBG loses some or all of its state (e.g., due to a power failure), it must recover the state so that packets can be forwarded over correct routes. If the EBG aggregates PA prefixes from which the IP prefixes of all EBRs in the enterprise are sub-delegated, then the EBG can recover state through DHCP prefix delegation lease renewals, through bulk lease queries, or through on-demand name-service lookups based due to IP packet forwarding. If the EBG serves as an anchor for PI prefixes, however, care must be taken to avoid looping while state is recovered through prefix registration RAs from EBRs. In that case, when the EBG that is recovering state forwards an IP packet for which it has no explicit route other than ::/0, it must first perform an on-demand name-service lookup to refresh state.
当EBG失去部分或全部状态（例如，由于电源故障）时，它必须恢复该状态，以便可以通过正确的路由转发数据包。如果EBG聚合了PA前缀，企业中所有EBR的IP前缀都是从这些PA前缀中转授的，则EBG可以通过DHCP前缀转授租约续订、批量租约查询或基于IP数据包转发的按需名称服务查找来恢复状态。但是，如果EBG充当PI前缀的锚，则必须注意避免在通过前缀注册RAs从EBRs恢复状态时发生循环。在这种情况下，当正在恢复状态的EBG转发其没有明确路由的IP数据包时，除了：：/0，它必须首先执行按需名称服务查找以刷新状态。
Security considerations for MANETs are found in [RFC2501].
移动自组网的安全注意事项见[RFC2501]。
Security considerations with tunneling that apply also to VET are found in [RFC2529] [RFC5214]. In particular, VET nodes must verify that the outer IP source address of a packet received on a VET interface is correct for the inner IP source address using the procedures specified in Section 7.3 of [RFC5214] in conjunction with the ingress filtering mechanisms specified in this document.
在[RFC2529][RFC5214]中可以找到同样适用于VET的隧道安全注意事项。特别是，VET节点必须使用[RFC5214]第7.3节中规定的程序以及本文件中规定的入口过滤机制，验证在VET接口上接收的数据包的外部IP源地址与内部IP源地址是否正确。
SEND [RFC3971], IPsec [RFC4301], and SEAL [RFC5320] provide additional securing mitigations to detect source address spoofing and bogus RA messages sent by rogue routers.
SEND[RFC3971]、IPsec[RFC4301]和SEAL[RFC5320]提供了额外的安全缓解措施，以检测恶意路由器发送的源地址欺骗和伪造RA消息。
Rogue routers can send bogus RA messages with spoofed RLOC source addresses that can consume network resources and cause EBGs to perform extra work. Nonetheless, EBGs should not "blacklist" such RLOCs, as that may result in a denial of service to the RLOCs' legitimate owners.
恶意路由器可以发送带有伪造RLOC源地址的虚假RA消息，这可能会消耗网络资源并导致EBG执行额外工作。尽管如此，EBG不应将此类RLOCs列入“黑名单”，因为这可能会导致拒绝向RLOCs的合法所有者提供服务。
Brian Carpenter and Cyndi Jung introduced the concept of intra-site automatic tunneling in [RFC2529]; this concept was later called: "Virtual Ethernet" and investigated by Quang Nguyen under the guidance of Dr. Lixia Zhang. Subsequent works by these authors and their colleagues have motivated a number of foundational concepts on which this work is based.
Brian Carpenter和Cyndi Jung在[RFC2529]中介绍了场内自动隧道的概念；这一概念后来被称为“虚拟以太网”，并由广元在张立霞博士的指导下进行了研究。这些作者及其同事的后续工作激发了许多基础概念，这项工作就是基于这些概念。
Telcordia has proposed DHCP-related solutions for MANETs through the CECOM MOSAIC program.
Telcordia通过CECOM MOSAIC计划为移动自组网提出了DHCP相关解决方案。
The Naval Research Lab (NRL) Information Technology Division uses DHCP in their MANET research testbeds.
海军研究实验室（NRL）信息技术部门在其MANET研究试验台上使用DHCP。
Security concerns pertaining to tunneling mechanisms are discussed in [TUNNEL-SEC].
与隧道机制相关的安全问题在[TUNNEL-SEC]中讨论。
Default router and prefix information options for DHCPv6 are discussed in [DEF-ROUTER].
DHCPv6的默认路由器和前缀信息选项在[DEF-router]中讨论。
An automated IPv4 prefix delegation mechanism is proposed in [SUBNET].
[SUBNET]中提出了一种自动IPv4前缀委派机制。
RLOC prefix delegation for enterprise-edge interfaces is discussed in [MANET-REC].
[MANET-REC]中讨论了企业边缘接口的RLOC前缀委派。
MANET link types are discussed in [LINKTYPE].
MANET链路类型在[LINKTYPE]中讨论。
Various proposals within the IETF have suggested similar mechanisms.
IETF内的各种提案提出了类似的机制。
The following individuals gave direct and/or indirect input that was essential to the work: Jari Arkko, Teco Boot, Emmanuel Bacelli, James Bound, Scott Brim, Brian Carpenter, Thomas Clausen, Claudiu Danilov, Ralph Droms, Dino Farinacci, Vince Fuller, Thomas Goff, Joel Halpern, Bob Hinden, Sapumal Jayatissa, Dan Jen, Darrel Lewis, Tony Li, Joe Macker, David Meyer, Thomas Narten, Pekka Nikander, Dave Oran, Alexandru Petrescu, John Spence, Jinmei Tatuya, Dave Thaler, Ole Troan, Michaela Vanderveen, Lixia Zhang, and others in the IETF AUTOCONF and MANET working groups. Many others have provided guidance over the course of many years.
以下人员提供了对工作至关重要的直接和/或间接输入：雅丽·阿克科、Teco Boot、伊曼纽尔·巴切利、詹姆斯·邦德、斯科特·布里姆、布赖恩·卡彭特、托马斯·克劳森、克劳迪乌·达尼洛夫、拉尔夫·德罗姆斯、迪诺·法里纳奇、文斯·富勒、托马斯·戈夫、乔尔·哈尔彭、鲍勃·欣登、萨普玛·贾亚蒂萨、丹·詹、达雷尔·刘易斯、托尼·李，Joe Macker、David Meyer、Thomas Narten、Pekka Nikander、Dave Oran、Alexandru Petrescu、John Spence、Jinmei Tatuya、Dave Thaler、Ole Troan、Michaela Vanderveen、Lixia Zhang以及IETF自动通信和MANET工作组的其他成员。许多其他人在多年的过程中提供了指导。
The following individuals have contributed to this document:
以下个人对本文件作出了贡献：
Eric Fleischman (eric.fleischman@boeing.com) Thomas Henderson (thomas.r.henderson@boeing.com) Steven Russert (steven.w.russert@boeing.com) Seung Yi (seung.yi@boeing.com)
埃里克·弗莱斯曼（埃里克。fleischman@boeing.com)托马斯·亨德森（托马斯·r。henderson@boeing.com)史蒂文·拉塞特（史蒂文·w。russert@boeing.com)承义（承）。yi@boeing.com)
Ian Chakeres (ian.chakeres@gmail.com) contributed to earlier versions of the document.
伊恩·查克斯（伊恩·查克斯）。chakeres@gmail.com)对文档的早期版本作出了贡献。
Jim Bound's foundational work on enterprise networks provided significant guidance for this effort. We mourn his loss and honor his contributions.
Jim Bound关于企业网络的基础工作为这项工作提供了重要的指导。我们哀悼他的损失，并对他的贡献表示敬意。
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1981.
[RFC0791]Postel，J.，“互联网协议”，STD 5，RFC 7911981年9月。
[RFC0792] Postel, J., "Internet Control Message Protocol", STD 5, RFC 792, September 1981.
[RFC0792]Postel，J.，“互联网控制消息协议”，STD 5，RFC 792，1981年9月。
[RFC0826] Plummer, D., "Ethernet Address Resolution Protocol: Or Converting Network Protocol Addresses to 48.bit Ethernet Address for Transmission on Ethernet Hardware", STD 37, RFC 826, November 1982.
[RFC0826]Plummer，D.，“以太网地址解析协议：或将网络协议地址转换为48位以太网地址，以便在以太网硬件上传输”，STD 37，RFC 826，1982年11月。
[RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987.
[RFC1035]Mockapetris，P.，“域名-实现和规范”，STD 13，RFC 1035，1987年11月。
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997.
[RFC2131]Droms，R.，“动态主机配置协议”，RFC21311997年3月。
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998.
[RFC2460]Deering，S.和R.Hinden，“互联网协议，第6版（IPv6）规范”，RFC 2460，1998年12月。
[RFC3007] Wellington, B., "Secure Domain Name System (DNS) Dynamic Update", RFC 3007, November 2000.
[RFC3007]惠灵顿，B.，“安全域名系统（DNS）动态更新”，RFC 3007，2000年11月。
[RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC3315]Droms，R.，Ed.，Bound，J.，Volz，B.，Lemon，T.，Perkins，C.，和M.Carney，“IPv6的动态主机配置协议（DHCPv6）”，RFC3315，2003年7月。
[RFC3596] Thomson, S., Huitema, C., Ksinant, V., and M. Souissi, "DNS Extensions to Support IP Version 6", RFC 3596, October 2003.
[RFC3596]Thomson，S.，Huitema，C.，Ksinant，V.，和M.Souissi，“支持IP版本6的DNS扩展”，RFC 3596，2003年10月。
[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, December 2003.
[RFC3633]Troan，O.和R.Droms，“动态主机配置协议（DHCP）版本6的IPv6前缀选项”，RFC 3633，2003年12月。
[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander, "SEcure Neighbor Discovery (SEND)", RFC 3971, March 2005.
[RFC3971]Arkko，J.，Ed.，Kempf，J.，Zill，B.，和P.Nikander，“安全邻居发现（SEND）”，RFC 39712005年3月。
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)", RFC 3972, March 2005.
[RFC3972]Aura，T.，“加密生成地址（CGA）”，RFC 39722005年3月。
[RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and More-Specific Routes", RFC 4191, November 2005.
[RFC4191]Draves，R.和D.Thaler，“默认路由器首选项和更具体的路由”，RFC 41912005年11月。
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, February 2006.
[RFC4291]Hinden，R.和S.Deering，“IP版本6寻址体系结构”，RFC 42912006年2月。
[RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", RFC 4443, March 2006.
[RFC4443]Conta，A.，Deering，S.，和M.Gupta，Ed.，“互联网协议版本6（IPv6）规范的互联网控制消息协议（ICMPv6）”，RFC 4443，2006年3月。
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007.
[RFC4861]Narten，T.，Nordmark，E.，Simpson，W.，和H.Soliman，“IP版本6（IPv6）的邻居发现”，RFC 48612007年9月。
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, September 2007.
[RFC4862]Thomson，S.，Narten，T.，和T.Jinmei，“IPv6无状态地址自动配置”，RFC 48622007年9月。
[RFC5214] Templin, F., Gleeson, T., and D. Thaler, "Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)", RFC 5214, March 2008.
[RFC5214]Templin，F.，Gleeson，T.，和D.Thaler，“站点内自动隧道寻址协议（ISATAP）”，RFC 52142008年3月。
[CATENET] Pouzin, L., "A Proposal for Interconnecting Packet Switching Networks", May 1974.
[CATENET]Pouzin，L.，“互连分组交换网络的提案”，1974年5月。
[mDNS] Cheshire, S. and M. Krochmal, "Multicast DNS", Work in Progress, September 2009.
[mDNS]Cheshire，S.和M.Krocmal，“多播DNS”，正在进行的工作，2009年9月。
[MANET-REC] Clausen, T. and U. Herberg, "MANET Router Configuration Recommendations", Work in Progress, February 2009.
[MANET-REC]Clausen，T.和U.Herberg，“MANET路由器配置建议”，正在进行的工作，2009年2月。
[LINKTYPE] Clausen, T., "The MANET Link Type", Work in Progress, October 2008.
[LINKTYPE]Clausen，T.，“移动自组网链路类型”，正在进行的工作，2008年10月。
[DEF-ROUTER] Droms, R. and T. Narten, "Default Router and Prefix Advertisement Options for DHCPv6", Work in Progress, October 2009.
[DEF-ROUTER]Droms，R.和T.Narten，“DHCPv6的默认路由器和前缀广告选项”，正在进行的工作，2009年10月。
[SEND-PROXY] Krishnan, S., Laganier, J., and M. Bonola, "Secure Proxy ND Support for SEND", Work in progress, July 2009.
[发送代理]Krishnan，S.，Laganier，J.，和M.Bonola，“发送的安全代理和支持”，正在进行的工作，2009年7月。
[SUBNET] Johnson, R., Kumarasamy, J., Kinnear, K., and M. Stapp, "Subnet Allocation Option", Work in Progress, October 2009.
[子网]Johnson，R.，Kumarasamy，J.，Kinnear，K.，和M.Stapp，“子网分配选项”，正在进行的工作，2009年10月。
[CENTRL-ULA] Hinden, R., Huston, G., and T. Narten, "Centrally Assigned Unique Local IPv6 Unicast Addresses", Work in Progress, June 2007.
[CENTRL-ULA]Hinden，R.，Huston，G.，和T.Narten，“集中分配的唯一本地IPv6单播地址”，正在进行的工作，2007年6月。
[MANET-SMF] Macker, J., Ed. and SMF Design Team, "Simplified Multicast Forwarding for MANET", Work in Progress, July 2009.
[MANET-SMF]Macker，J.，Ed.和SMF设计团队，“MANET的简化多播转发”，正在进行的工作，2009年7月。
[TUNNEL-SEC] Hoagland, J., Krishnan, S., and D. Thaler, "Security Concerns With IP Tunneling", Work in Progress, October 2008.
[TUNNEL-SEC]Hoagland，J.，Krishnan，S.，和D.Thaler，“IP隧道的安全问题”，正在进行的工作，2008年10月。
[APT] Jen, D., Meisel, M., Massey, D., Wang, L., Zhang, B., and L. Zhang, "APT: A Practical Transit Mapping Service", Work in Progress, November 2007.
[APT]Jen，D.，Meisel，M.，Massey，D.，Wang，L.，Zhang，B.，和L.Zhang，“APT：一种实用的交通测绘服务”，正在进行的工作，2007年11月。
[IEN48] Cerf, V., "The Catenet Model for Internetworking", IEN 48, July 1978.
[IEN48]Cerf，V.，“互联网的Catenet模型”，IEN48，1978年7月。
[RASADV] Microsoft, "Remote Access Server Advertisement (RASADV) Protocol Specification", October 2008.
[RASADV]微软，“远程访问服务器广告（RASADV）协议规范”，2008年10月。
[RFC1122] Braden, R., Ed., "Requirements for Internet Hosts - Communication Layers", STD 3, RFC 1122, October 1989.
[RFC1122]Braden，R.，Ed.“互联网主机的要求-通信层”，STD 3，RFC 1122，1989年10月。
[RFC1256] Deering, S., Ed., "ICMP Router Discovery Messages", RFC 1256, September 1991.
[RFC1256]迪林，S.，编辑，“ICMP路由器发现消息”，RFC1256，1991年9月。
[RFC1753] Chiappa, N., "IPng Technical Requirements Of the Nimrod Routing and Addressing Architecture", RFC 1753, December 1994.
[RFC1753]Chiapa，N.，“Nimrod路由和寻址体系结构的IPng技术要求”，RFC 1753，1994年12月。
[RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G., and E. Lear, "Address Allocation for Private Internets", BCP 5, RFC 1918, February 1996.
[RFC1918]Rekhter，Y.，Moskowitz，B.，Karrenberg，D.，de Groot，G.，和E.Lear，“私人互联网地址分配”，BCP 5，RFC 1918，1996年2月。
[RFC1955] Hinden, R., "New Scheme for Internet Routing and Addressing (ENCAPS) for IPNG", RFC 1955, June 1996.
[RFC1955]Hinden，R.，“IPNG的互联网路由和寻址新方案（ENCAPS）”，RFC 19551996年6月。
[RFC2501] Corson, S. and J. Macker, "Mobile Ad hoc Networking (MANET): Routing Protocol Performance Issues and Evaluation Considerations", RFC 2501, January 1999.
[RFC2501]Corson，S.和J.Macker，“移动自组网（MANET）：路由协议性能问题和评估考虑”，RFC 2501，1999年1月。
[RFC2529] Carpenter, B. and C. Jung, "Transmission of IPv6 over IPv4 Domains without Explicit Tunnels", RFC 2529, March 1999.
[RFC2529]Carpenter，B.和C.Jung，“在没有明确隧道的IPv4域上传输IPv6”，RFC 2529，1999年3月。
[RFC2775] Carpenter, B., "Internet Transparency", RFC 2775, February 2000.
[RFC2775]Carpenter，B.，“互联网透明度”，RFC 27752000年2月。
[RFC3704] Baker, F. and P. Savola, "Ingress Filtering for Multihomed Networks", BCP 84, RFC 3704, March 2004.
[RFC3704]Baker，F.和P.Savola，“多宿网络的入口过滤”，BCP 84，RFC 37042004年3月。
[RFC3819] Karn, P., Ed., Bormann, C., Fairhurst, G., Grossman, D., Ludwig, R., Mahdavi, J., Montenegro, G., Touch, J., and L. Wood, "Advice for Internet Subnetwork Designers", BCP 89, RFC 3819, July 2004.
[RFC3819]Karn，P.，Ed.，Bormann，C.，Fairhurst，G.，Grossman，D.，Ludwig，R.，Mahdavi，J.，黑山，G.，Touch，J.，和L.Wood，“互联网子网络设计师的建议”，BCP 89，RFC 3819，2004年7月。
[RFC3927] Cheshire, S., Aboba, B., and E. Guttman, "Dynamic Configuration of IPv4 Link-Local Addresses", RFC 3927, May 2005.
[RFC3927]Cheshire，S.，Aboba，B.和E.Guttman，“IPv4链路本地地址的动态配置”，RFC 3927，2005年5月。
[RFC4192] Baker, F., Lear, E., and R. Droms, "Procedures for Renumbering an IPv6 Network without a Flag Day", RFC 4192, September 2005.
[RFC4192]Baker，F.，Lear，E.，和R.Droms，“在没有国旗日的情况下对IPv6网络重新编号的程序”，RFC 41922005年9月。
[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast Addresses", RFC 4193, October 2005.
[RFC4193]Hinden，R.和B.Haberman，“唯一本地IPv6单播地址”，RFC 41932005年10月。
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, December 2005.
[RFC4301]Kent，S.和K.Seo，“互联网协议的安全架构”，RFC 43012005年12月。
[RFC4380] Huitema, C., "Teredo: Tunneling IPv6 over UDP through Network Address Translations (NATs)", RFC 4380, February 2006.
[RFC4380]Huitema，C.，“Teredo：通过网络地址转换（NAT）通过UDP传输IPv6”，RFC 43802006年2月。
[RFC4389] Thaler, D., Talwar, M., and C. Patel, "Neighbor Discovery Proxies (ND Proxy)", RFC 4389, April 2006.
[RFC4389]Thaler，D.，Talwar，M.，和C.Patel，“邻居发现代理（ND代理）”，RFC 4389，2006年4月。
[RFC4795] Aboba, B., Thaler, D., and L. Esibov, "Link-Local Multicast Name Resolution (LLMNR)", RFC 4795, January 2007.
[RFC4795]Aboba，B.，Thaler，D.，和L.Esibov，“链路本地多播名称解析（LLMNR）”，RFC 47952007年1月。
[RFC4852] Bound, J., Pouffary, Y., Klynsma, S., Chown, T., and D. Green, "IPv6 Enterprise Network Analysis - IP Layer 3 Focus", RFC 4852, April 2007.
[RFC4852]Bound，J.，Pouffary，Y.，Klynsma，S.，Chown，T.，和D.Green，“IPv6企业网络分析-IP层3焦点”，RFC 48522007年4月。
[RFC4903] Thaler, D., "Multi-Link Subnet Issues", RFC 4903, June 2007.
[RFC4903]Thaler，D.，“多链路子网问题”，RFC 49032007年6月。
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy Extensions for Stateless Address Autoconfiguration in IPv6", RFC 4941, September 2007.
[RFC4941]Narten，T.，Draves，R.，和S.Krishnan，“IPv6中无状态地址自动配置的隐私扩展”，RFC 49412007年9月。
[RFC5320] Templin, F., "The Subnetwork Encapsulation and Adaptation Layer (SEAL)", RFC 5320, February 2010.
[RFC5320]Templin，F.“子网络封装和适配层（密封）”，RFC 5320，2010年2月。
[RFC5720] Templin, F., "Routing and Addressing in Networks with Global Enterprise Recursion (RANGER)", RFC 5720, February 2010.
[RFC5720]Templin，F.“具有全局企业递归（RANGER）的网络中的路由和寻址”，RFC 5720，2010年2月。
[RANGERS] Russert, S., Ed., Fleischman, E., Ed., and F. Templin, Ed., "RANGER Scenarios", Work in Progress, September 2009.
[游骑兵]拉塞特，S.，编辑，弗莱斯曼，E.，编辑和F.坦普林，编辑，“游骑兵场景”，正在进行的工作，2009年9月。
Appendix A. Duplicate Address Detection (DAD) Considerations
附录A.重复地址检测（DAD）注意事项
A priori uniqueness determination (also known as "pre-service DAD") for an RLOC assigned on an enterprise-interior interface would require either flooding the entire enterprise or somehow discovering a link in the enterprise on which a node that configures a duplicate address is attached and performing a localized DAD exchange on that link. But, the control message overhead for such an enterprise-wide DAD would be substantial and prone to false-negatives due to packet loss and intermittent connectivity. An alternative to pre-service DAD is to autoconfigure pseudo-random RLOCs on enterprise-interior interfaces and employ a passive in-service DAD (e.g., one that monitors routing protocol messages for duplicate assignments).
在企业内部接口上分配的RLOC的先验唯一性确定（也称为“服务前DAD”）将需要淹没整个企业，或者以某种方式发现企业中连接了配置重复地址的节点的链接，并在该链接上执行本地化DAD交换。但是，这样一个企业范围的DAD的控制消息开销将是巨大的，并且由于数据包丢失和间歇性连接而容易出现误报。服务前DAD的另一种替代方法是在企业内部接口上自动配置伪随机RLOC，并使用被动的服务内DAD（例如，监视路由协议消息的重复分配）。
Pseudo-random IPv6 RLOCs can be generated with mechanisms such as CGAs, IPv6 privacy addresses, etc. with very small probability of collision. Pseudo-random IPv4 RLOCs can be generated through random assignment from a suitably large IPv4 prefix space.
伪随机IPv6 RLOC可以通过CGA、IPv6隐私地址等机制生成，冲突概率非常小。伪随机IPv4 RLOC可以通过从适当大的IPv4前缀空间进行随机分配来生成。
Consistent operational practices can assure uniqueness for EBG-aggregated addresses/prefixes, while statistical properties for pseudo-random address self-generation can assure uniqueness for the RLOCs assigned on an ER's enterprise-interior interfaces. Still, an RLOC delegation authority should be used when available, while a passive in-service DAD mechanism should be used to detect RLOC duplications when there is no RLOC delegation authority.
一致的操作实践可以确保EBG聚合地址/前缀的唯一性，而伪随机地址自生成的统计特性可以确保分配给ER企业内部接口的RLOC的唯一性。尽管如此，在可用时仍应使用RLOC委派权限，而在没有RLOC委派权限时，应使用被动的在用DAD机制来检测RLOC重复。
Author's Address
作者地址
Fred L. Templin (editor) Boeing Research & Technology P.O. Box 3707 MC 7L-49 Seattle, WA 98124 USA
Fred L.Templin（编辑）美国华盛顿州西雅图波音研究与技术公司邮政信箱3707 MC 7L-49 98124
EMail: fltemplin@acm.org
EMail: fltemplin@acm.org