Internet Engineering Task Force (IETF) S. Nadas, Ed.
Request for Comments: 5798 Ericsson
Obsoletes: 3768 March 2010
Category: Standards Track
ISSN: 2070-1721
Internet Engineering Task Force (IETF) S. Nadas, Ed.
Request for Comments: 5798 Ericsson
Obsoletes: 3768 March 2010
Category: Standards Track
ISSN: 2070-1721
Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6
IPv4和IPv6的虚拟路由器冗余协议（VRRP）版本3
Abstract
摘要
This memo defines the Virtual Router Redundancy Protocol (VRRP) for IPv4 and IPv6. It is version three (3) of the protocol, and it is based on VRRP (version 2) for IPv4 that is defined in RFC 3768 and in "Virtual Router Redundancy Protocol for IPv6". VRRP specifies an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. The VRRP router controlling the IPv4 or IPv6 address(es) associated with a virtual router is called the Master, and it forwards packets sent to these IPv4 or IPv6 addresses. VRRP Master routers are configured with virtual IPv4 or IPv6 addresses, and VRRP Backup routers infer the address family of the virtual addresses being carried based on the transport protocol. Within a VRRP router, the virtual routers in each of the IPv4 and IPv6 address families are a domain unto themselves and do not overlap. The election process provides dynamic failover in the forwarding responsibility should the Master become unavailable. For IPv4, the advantage gained from using VRRP is a higher-availability default path without requiring configuration of dynamic routing or router discovery protocols on every end-host. For IPv6, the advantage gained from using VRRP for IPv6 is a quicker switchover to Backup routers than can be obtained with standard IPv6 Neighbor Discovery mechanisms.
此备忘录定义了IPv4和IPv6的虚拟路由器冗余协议（VRRP）。它是协议的第三（3）版，基于RFC 3768和“IPv6虚拟路由器冗余协议”中定义的IPv4 VRRP（第2版）。VRRP指定一个选择协议，该协议动态地将虚拟路由器的责任分配给LAN上的一个VRRP路由器。控制与虚拟路由器关联的IPv4或IPv6地址的VRRP路由器称为主路由器，它转发发送到这些IPv4或IPv6地址的数据包。VRRP主路由器配置有虚拟IPv4或IPv6地址，VRRP备份路由器根据传输协议推断所承载虚拟地址的地址族。在VRRP路由器中，IPv4和IPv6地址族中的每一个虚拟路由器本身都是一个域，不重叠。如果主机不可用，选择过程在转发责任中提供动态故障切换。对于IPv4，使用VRRP所获得的优势是更高的可用性默认路径，而无需在每个终端主机上配置动态路由或路由器发现协议。对于IPv6，与标准IPv6邻居发现机制相比，将VRRP用于IPv6所获得的优势是更快地切换到备份路由器。
Status of This Memo
关于下段备忘
This is an Internet Standards Track document.
这是一份互联网标准跟踪文件。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。有关互联网标准的更多信息，请参见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/rfc5798.
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/rfc5798.
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. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
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。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English.
本文件可能包含2008年11月10日之前发布或公开的IETF文件或IETF贡献中的材料。控制某些材料版权的人员可能未授予IETF信托允许在IETF标准流程之外修改此类材料的权利。在未从控制此类材料版权的人员处获得充分许可的情况下，不得在IETF标准流程之外修改本文件，也不得在IETF标准流程之外创建其衍生作品，除了将其格式化以RFC形式发布或将其翻译成英语以外的其他语言。
Table of Contents
目录
1. Introduction ....................................................4
1.1. A Note on Terminology ......................................4
1.2. IPv4 .......................................................5
1.3. IPv6 .......................................................6
1.4. Requirements Language ......................................6
1.5. Scope ......................................................7
1.6. Definitions ................................................7
2. Required Features ...............................................8
2.1. IPvX Address Backup ........................................8
2.2. Preferred Path Indication ..................................8
2.3. Minimization of Unnecessary Service Disruptions ............9
2.4. Efficient Operation over Extended LANs .....................9
2.5. Sub-Second Operation for IPv4 and IPv6 .....................9
3. VRRP Overview ..................................................10
4. Sample Configurations ..........................................11
4.1. Sample Configuration 1 ....................................11
4.2. Sample Configuration 2 ....................................13
1. Introduction ....................................................4
1.1. A Note on Terminology ......................................4
1.2. IPv4 .......................................................5
1.3. IPv6 .......................................................6
1.4. Requirements Language ......................................6
1.5. Scope ......................................................7
1.6. Definitions ................................................7
2. Required Features ...............................................8
2.1. IPvX Address Backup ........................................8
2.2. Preferred Path Indication ..................................8
2.3. Minimization of Unnecessary Service Disruptions ............9
2.4. Efficient Operation over Extended LANs .....................9
2.5. Sub-Second Operation for IPv4 and IPv6 .....................9
3. VRRP Overview ..................................................10
4. Sample Configurations ..........................................11
4.1. Sample Configuration 1 ....................................11
4.2. Sample Configuration 2 ....................................13
5. Protocol .......................................................14
5.1. VRRP Packet Format ........................................15
5.1.1. IPv4 Field Descriptions ............................15
5.1.1.1. Source Address ............................15
5.1.1.2. Destination Address .......................15
5.1.1.3. TTL .......................................16
5.1.1.4. Protocol ..................................16
5.1.2. IPv6 Field Descriptions ............................16
5.1.2.1. Source Address ............................16
5.1.2.2. Destination Address .......................16
5.1.2.3. Hop Limit .................................16
5.1.2.4. Next Header ...............................16
5.2. VRRP Field Descriptions ...................................16
5.2.1. Version ............................................16
5.2.2. Type ...............................................17
5.2.3. Virtual Rtr ID (VRID) ..............................17
5.2.4. Priority ...........................................17
5.2.5. Count IPvX Addr ....................................17
5.2.6. Rsvd ...............................................17
5.2.7. Maximum Advertisement Interval (Max Adver Int) .....17
5.2.8. Checksum ...........................................18
5.2.9. IPvX Address(es) ...................................18
6. Protocol State Machine .........................................18
6.1. Parameters Per Virtual Router .............................18
6.2. Timers ....................................................20
6.3. State Transition Diagram ..................................21
6.4. State Descriptions ........................................21
6.4.1. Initialize .........................................21
6.4.2. Backup .............................................22
6.4.3. Master .............................................24
7. Sending and Receiving VRRP Packets .............................26
7.1. Receiving VRRP Packets ....................................26
7.2. Transmitting VRRP Packets .................................27
7.3. Virtual Router MAC Address ................................28
7.4. IPv6 Interface Identifiers ................................28
8. Operational Issues .............................................29
8.1. IPv4 ......................................................29
8.1.1. ICMP Redirects .....................................29
8.1.2. Host ARP Requests ..................................29
8.1.3. Proxy ARP ..........................................30
8.2. IPv6 ......................................................30
8.2.1. ICMPv6 Redirects ...................................30
8.2.2. ND Neighbor Solicitation ...........................30
8.2.3. Router Advertisements ..............................31
8.3. IPvX ......................................................31
8.3.1. Potential Forwarding Loop ..........................31
8.3.2. Recommendations Regarding Setting Priority Values ..32
5. Protocol .......................................................14
5.1. VRRP Packet Format ........................................15
5.1.1. IPv4 Field Descriptions ............................15
5.1.1.1. Source Address ............................15
5.1.1.2. Destination Address .......................15
5.1.1.3. TTL .......................................16
5.1.1.4. Protocol ..................................16
5.1.2. IPv6 Field Descriptions ............................16
5.1.2.1. Source Address ............................16
5.1.2.2. Destination Address .......................16
5.1.2.3. Hop Limit .................................16
5.1.2.4. Next Header ...............................16
5.2. VRRP Field Descriptions ...................................16
5.2.1. Version ............................................16
5.2.2. Type ...............................................17
5.2.3. Virtual Rtr ID (VRID) ..............................17
5.2.4. Priority ...........................................17
5.2.5. Count IPvX Addr ....................................17
5.2.6. Rsvd ...............................................17
5.2.7. Maximum Advertisement Interval (Max Adver Int) .....17
5.2.8. Checksum ...........................................18
5.2.9. IPvX Address(es) ...................................18
6. Protocol State Machine .........................................18
6.1. Parameters Per Virtual Router .............................18
6.2. Timers ....................................................20
6.3. State Transition Diagram ..................................21
6.4. State Descriptions ........................................21
6.4.1. Initialize .........................................21
6.4.2. Backup .............................................22
6.4.3. Master .............................................24
7. Sending and Receiving VRRP Packets .............................26
7.1. Receiving VRRP Packets ....................................26
7.2. Transmitting VRRP Packets .................................27
7.3. Virtual Router MAC Address ................................28
7.4. IPv6 Interface Identifiers ................................28
8. Operational Issues .............................................29
8.1. IPv4 ......................................................29
8.1.1. ICMP Redirects .....................................29
8.1.2. Host ARP Requests ..................................29
8.1.3. Proxy ARP ..........................................30
8.2. IPv6 ......................................................30
8.2.1. ICMPv6 Redirects ...................................30
8.2.2. ND Neighbor Solicitation ...........................30
8.2.3. Router Advertisements ..............................31
8.3. IPvX ......................................................31
8.3.1. Potential Forwarding Loop ..........................31
8.3.2. Recommendations Regarding Setting Priority Values ..32
8.4. VRRPv3 and VRRPv2 Interoperation ..........................32
8.4.1. Assumptions ........................................32
8.4.2. VRRPv3 Support of VRRPv2 ...........................32
8.4.3. VRRPv3 Support of VRRPv2 Considerations ............33
8.4.3.1. Slow, High-Priority Masters ...............33
8.4.3.2. Overwhelming VRRPv2 Backups ...............33
9. Security Considerations ........................................33
10. Contributors and Acknowledgments ..............................34
11. IANA Considerations ...........................................35
12. References ....................................................35
12.1. Normative References .....................................35
12.2. Informative References ...................................36
Appendix A. Operation over FDDI, Token Ring, and ATM LANE .........38
A.1. Operation over FDDI .......................................38
A.2. Operation over Token Ring .................................38
A.3. Operation over ATM LANE ...................................40
8.4. VRRPv3 and VRRPv2 Interoperation ..........................32
8.4.1. Assumptions ........................................32
8.4.2. VRRPv3 Support of VRRPv2 ...........................32
8.4.3. VRRPv3 Support of VRRPv2 Considerations ............33
8.4.3.1. Slow, High-Priority Masters ...............33
8.4.3.2. Overwhelming VRRPv2 Backups ...............33
9. Security Considerations ........................................33
10. Contributors and Acknowledgments ..............................34
11. IANA Considerations ...........................................35
12. References ....................................................35
12.1. Normative References .....................................35
12.2. Informative References ...................................36
Appendix A. Operation over FDDI, Token Ring, and ATM LANE .........38
A.1. Operation over FDDI .......................................38
A.2. Operation over Token Ring .................................38
A.3. Operation over ATM LANE ...................................40
This memo defines the Virtual Router Redundancy Protocol (VRRP) for IPv4 and IPv6. It is version three (3) of the protocol. It is based on VRRP (version 2) for IPv4 that is defined in [RFC3768] and in [VRRP-IPv6]. VRRP specifies an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. The VRRP router controlling the IPv4 or IPv6 address(es) associated with a virtual router is called the Master, and it forwards packets sent to these IPv4 or IPv6 addresses. VRRP Master routers are configured with virtual IPv4 or IPv6 addresses, and VRRP Backup routers infer the address family of the virtual addresses being carried based on the transport protocol. Within a VRRP router, the virtual routers in each of the IPv4 and IPv6 address families are a domain unto themselves and do not overlap. The election process provides dynamic failover in the forwarding responsibility should the Master become unavailable.
此备忘录定义了IPv4和IPv6的虚拟路由器冗余协议（VRRP）。这是协议的第三（3）版。它基于[RFC3768]和[VRRP-IPv6]中定义的IPv4的VRRP（版本2）。VRRP指定一个选择协议，该协议动态地将虚拟路由器的责任分配给LAN上的一个VRRP路由器。控制与虚拟路由器关联的IPv4或IPv6地址的VRRP路由器称为主路由器，它转发发送到这些IPv4或IPv6地址的数据包。VRRP主路由器配置有虚拟IPv4或IPv6地址，VRRP备份路由器根据传输协议推断所承载虚拟地址的地址族。在VRRP路由器中，IPv4和IPv6地址族中的每一个虚拟路由器本身都是一个域，不重叠。如果主机不可用，选择过程在转发责任中提供动态故障切换。
VRRP provides a function similar to the proprietary protocols "Hot Standby Router Protocol (HSRP)" [RFC2281] and "IP Standby Protocol" [IPSTB].
VRRP提供的功能类似于专有协议“热备用路由器协议（HSRP）”[RFC2281]和“IP备用协议”[IPSTB]。
This document discusses both IPv4 and IPv6 operation, and with respect to the VRRP protocol, many of the descriptions and procedures are common. In this document, it would be less verbose to be able to refer to "IP" to mean either "IPv4 or IPv6". However, historically, the term "IP" usually refers to IPv4. For this reason, in this specification, the term "IPvX" (where X is 4 or 6) is introduced to mean either "IPv4" or "IPv6". In this text, where the IP version
本文档讨论IPv4和IPv6操作，关于VRRP协议，许多描述和过程是通用的。在本文档中，如果能够将“IP”指代为“IPv4或IPv6”，则不会太详细。然而，历史上，“IP”一词通常指IPv4。因此，在本规范中，术语“IPvX”（其中X为4或6）表示“IPv4”或“IPv6”。在本文中，IP版本
matters, the appropriate term is used and the use of the term "IP" is avoided.
在这些问题上，使用适当的术语，避免使用术语“IP”。
There are a number of methods that an IPv4 end-host can use to determine its first-hop router towards a particular IPv4 destination. These include running (or snooping) a dynamic routing protocol such as Routing Information Protocol [RFC2453] or OSPF version 2 [RFC2328], running an ICMP router discovery client [RFC1256], or using a statically configured default route.
IPv4终端主机可以使用多种方法确定其朝向特定IPv4目标的第一跳路由器。这些包括运行（或窥探）动态路由协议，如路由信息协议[RFC2453]或OSPF版本2[RFC2328]，运行ICMP路由器发现客户端[RFC1256]，或使用静态配置的默认路由。
Running a dynamic routing protocol on every end-host may be infeasible for a number of reasons, including administrative overhead, processing overhead, security issues, or lack of a protocol implementation for some platforms. Neighbor or router discovery protocols may require active participation by all hosts on a network, leading to large timer values to reduce protocol overhead in the face of large numbers of hosts. This can result in a significant delay in the detection of a lost (i.e., dead) neighbor; such a delay may introduce unacceptably long "black hole" periods.
由于许多原因，在每个终端主机上运行动态路由协议可能是不可行的，包括管理开销、处理开销、安全问题，或者某些平台缺少协议实现。邻居或路由器发现协议可能需要网络上所有主机的积极参与，从而导致较大的计时器值，以减少面对大量主机时的协议开销。这可能导致丢失（即，死亡）邻居检测的显著延迟；这样的延迟可能会引入不可接受的长“黑洞”周期。
The use of a statically configured default route is quite popular; it minimizes configuration and processing overhead on the end-host and is supported by virtually every IPv4 implementation. This mode of operation is likely to persist as dynamic host configuration protocols [RFC2131] are deployed, which typically provide configuration for an end-host IPv4 address and default gateway. However, this creates a single point of failure. Loss of the default router results in a catastrophic event, isolating all end-hosts that are unable to detect any alternate path that may be available.
使用静态配置的默认路由非常流行；它最大限度地减少了终端主机上的配置和处理开销，几乎每个IPv4实现都支持它。随着动态主机配置协议[RFC2131]的部署，这种操作模式可能会持续下去，动态主机配置协议通常为终端主机IPv4地址和默认网关提供配置。但是，这会造成单点故障。丢失默认路由器会导致灾难性事件，隔离所有无法检测任何可用备用路径的终端主机。
The Virtual Router Redundancy Protocol (VRRP) is designed to eliminate the single point of failure inherent in the static default-routed environment. VRRP specifies an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. The VRRP router controlling the IPv4 address(es) associated with a virtual router is called the Master and forwards packets sent to these IPv4 addresses. The election process provides dynamic failover in the forwarding responsibility should the Master become unavailable. Any of the virtual router's IPv4 addresses on a LAN can then be used as the default first hop
虚拟路由器冗余协议（VRRP）旨在消除静态默认路由环境中固有的单点故障。VRRP指定一个选择协议，该协议动态地将虚拟路由器的责任分配给LAN上的一个VRRP路由器。控制与虚拟路由器关联的IPv4地址的VRRP路由器称为主路由器，并转发发送到这些IPv4地址的数据包。如果主机不可用，选择过程在转发责任中提供动态故障切换。局域网上的任何虚拟路由器的IPv4地址都可以用作默认的第一跳
router by end-hosts. The advantage gained from using VRRP is a higher availability default path without requiring configuration of dynamic routing or router discovery protocols on every end-host.
终端主机的路由器。使用VRRP的优点是，无需在每个终端主机上配置动态路由或路由器发现协议，即可获得更高的可用性默认路径。
IPv6 hosts on a LAN will usually learn about one or more default routers by receiving Router Advertisements sent using the IPv6 Neighbor Discovery (ND) protocol [RFC4861]. The Router Advertisements are multicast periodically at a rate that the hosts will learn about the default routers in a few minutes. They are not sent frequently enough to rely on the absence of the Router Advertisement to detect router failures.
局域网上的IPv6主机通常通过接收使用IPv6邻居发现（ND）协议[RFC4861]发送的路由器广告来了解一个或多个默认路由器。路由器广告以主机将在几分钟内了解默认路由器的速率定期进行多播。它们的发送频率不足以依赖路由器广告的缺失来检测路由器故障。
Neighbor Discovery (ND) includes a mechanism called Neighbor Unreachability Detection to detect the failure of a neighbor node (router or host) or the forwarding path to a neighbor. This is done by sending unicast ND Neighbor Solicitation messages to the neighbor node. To reduce the overhead of sending Neighbor Solicitations, they are only sent to neighbors to which the node is actively sending traffic and only after there has been no positive indication that the router is up for a period of time. Using the default parameters in ND, it will take a host about 38 seconds to learn that a router is unreachable before it will switch to another default router. This delay would be very noticeable to users and cause some transport protocol implementations to time out.
邻居发现（ND）包括一种称为邻居不可达性检测的机制，用于检测邻居节点（路由器或主机）的故障或到邻居的转发路径。这是通过向邻居节点发送单播ND邻居请求消息来实现的。为了减少发送邻居请求的开销，这些请求仅发送给节点正在向其主动发送流量的邻居，并且仅在没有路由器运行一段时间的肯定指示之后发送。使用ND中的默认参数，主机在切换到另一个默认路由器之前，需要大约38秒的时间才能知道某个路由器无法访问。这种延迟对于用户来说非常明显，并导致一些传输协议实现超时。
While the ND unreachability detection could be made quicker by changing the parameters to be more aggressive (note that the current lower limit for this is 5 seconds), this would have the downside of significantly increasing the overhead of ND traffic, especially when there are many hosts all trying to determine the reachability of one of more routers.
虽然可以通过将参数更改为更具攻击性（注意，当前的下限为5秒）来加快ND不可达性检测，但这会显著增加ND流量的开销，特别是当有许多主机都试图确定一个或多个路由器的可达性时。
The Virtual Router Redundancy Protocol for IPv6 provides a much faster switchover to an alternate default router than can be obtained using standard ND procedures. Using VRRP, a Backup router can take over for a failed default router in around three seconds (using VRRP default parameters). This is done without any interaction with the hosts and a minimum amount of VRRP traffic.
IPv6虚拟路由器冗余协议提供了比使用标准ND过程更快的到备用默认路由器的切换。使用VRRP，备份路由器可以在大约三秒钟内接管故障的默认路由器（使用VRRP默认参数）。这是在不与主机进行任何交互的情况下完成的，并且VRRP通信量最少。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照[RFC2119]中所述进行解释。
The remainder of this document describes the features, design goals, and theory of operation of VRRP. The message formats, protocol processing rules, and state machine that guarantee convergence to a single Virtual Router Master are presented. Finally, operational issues related to MAC address mapping, handling of ARP requests, generation of ICMP redirect messages, and security issues are addressed.
本文件的其余部分描述了VRRP的特点、设计目标和运行理论。介绍了保证收敛到单个虚拟路由器主机的消息格式、协议处理规则和状态机。最后，讨论了与MAC地址映射、ARP请求处理、ICMP重定向消息生成和安全问题相关的操作问题。
VRRP Router A router running the Virtual Router Redundancy Protocol. It may participate as one or more virtual routers.
VRRP路由器运行虚拟路由器冗余协议的路由器。它可以作为一个或多个虚拟路由器参与。
Virtual Router An abstract object managed by VRRP that acts as a default router for hosts on a shared LAN. It consists of a Virtual Router Identifier and either a set of associated IPv4 addresses or a set of associated IPv6 addresses across a common LAN. A VRRP Router may back up one or more virtual routers.
虚拟路由器由VRRP管理的抽象对象，用作共享LAN上主机的默认路由器。它由一个虚拟路由器标识符和一组关联的IPv4地址或一组跨公共LAN的关联IPv6地址组成。VRRP路由器可以备份一个或多个虚拟路由器。
IP Address Owner The VRRP router that has the virtual router's IPvX address(es) as real interface address(es). This is the router that, when up, will respond to packets addressed to one of these IPvX addresses for ICMP pings, TCP connections, etc.
IP地址所有者将虚拟路由器的IPvX地址作为实际接口地址的VRRP路由器。这是一个路由器，当它启动时，将响应发送到这些IPvX地址之一的数据包，用于ICMP ping、TCP连接等。
Primary IP Address In IPv4, an IPv4 address selected from the set of real interface addresses. One possible selection algorithm is to always select the first address. In IPv4 mode, VRRP advertisements are always sent using the primary IPv4 address as the source of the IPv4 packet. In IPv6, the link-local address of the interface over which the packet is transmitted is used.
IPv4中的主IP地址，从实际接口地址集中选择的IPv4地址。一种可能的选择算法是始终选择第一个地址。在IPv4模式下，始终使用主IPv4地址作为IPv4数据包的源发送VRRP播发。在IPv6中，使用数据包传输接口的链路本地地址。
Virtual Router Master The VRRP router that is assuming the responsibility of forwarding packets sent to the IPvX address(es) associated with the virtual router, answering ARP requests
虚拟路由器主控VRRP路由器，负责转发发送到与虚拟路由器相关的IPvX地址的数据包，应答ARP请求
for the IPv4 address(es), and answering ND requests for the IPv6 address(es). Note that if the IPvX address owner is available, then it will always become the Master.
用于IPv4地址，并应答IPv6地址的ND请求。请注意，如果IPvX地址所有者可用，则它将始终成为主地址。
Virtual Router Backup The set of VRRP routers available to assume forwarding responsibility for a virtual router should the current Master fail.
虚拟路由器备份如果当前主路由器出现故障，可用于承担虚拟路由器转发责任的一组VRRP路由器。
This section outlines the set of features that were considered mandatory and that guided the design of VRRP.
本节概述了被认为是强制性的、指导VRRP设计的一系列功能。
Backup of an IPvX address or addresses is the primary function of VRRP. While providing election of a Virtual Router Master and the additional functionality described below, the protocol should strive to:
一个或多个IPvX地址的备份是VRRP的主要功能。在提供虚拟路由器主机的选择和下面描述的附加功能的同时，协议应努力：
o Minimize the duration of black holes.
o 尽量减少黑洞的持续时间。
o Minimize the steady-state bandwidth overhead and processing complexity.
o 最小化稳态带宽开销和处理复杂性。
o Function over a wide variety of multiaccess LAN technologies capable of supporting IPvX traffic.
o 在多种多址LAN技术上运行，能够支持IPvX通信。
o Allow multiple virtual routers on a network for load balancing.
o 允许网络上的多个虚拟路由器进行负载平衡。
o Support multiple logical IPvX subnets on a single LAN segment.
o 支持单个LAN网段上的多个逻辑IPvX子网。
A simple model of Master election among a set of redundant routers is to treat each router with equal preference and claim victory after converging to any router as Master. However, there are likely to be many environments where there is a distinct preference (or range of preferences) among the set of redundant routers. For example, this preference may be based upon access link cost or speed, router performance or reliability, or other policy considerations. The protocol should allow the expression of this relative path preference in an intuitive manner and guarantee Master convergence to the most preferential router currently available.
在一组冗余路由器中，主选择的一个简单模型是以相同的偏好对待每个路由器，并在收敛到任何一个路由器作为主路由器后声称胜利。然而，在许多环境中，冗余路由器组之间可能存在明显的偏好（或偏好范围）。例如，此偏好可基于接入链路成本或速度、路由器性能或可靠性或其他策略考虑。该协议应允许以直观的方式表达这种相对路径偏好，并保证主机收敛到当前可用的最优先路由器。
Once Master election has been performed, any unnecessary transitions between Master and Backup routers can result in a disruption in service. The protocol should ensure after Master election that no state transition is triggered by any Backup router of equal or lower preference as long as the Master continues to function properly.
一旦执行了主选择，主路由器和备份路由器之间任何不必要的转换都可能导致服务中断。协议应确保在主设备选择后，只要主设备继续正常工作，具有相同或更低优先级的任何备份路由器都不会触发状态转换。
Some environments may find it beneficial to avoid the state transition triggered when a router that is preferred over the current Master becomes available. It may be useful to support an override of the immediate convergence to the preferred path.
某些环境可能会发现，避免在优先于当前主机的路由器可用时触发状态转换是有益的。支持覆盖立即收敛到首选路径可能很有用。
Sending IPvX packets (that is, sending either IPv4 or IPv6) on a multiaccess LAN requires mapping from an IPvX address to a MAC address. The use of the virtual router MAC address in an extended LAN employing learning bridges can have a significant effect on the bandwidth overhead of packets sent to the virtual router. If the virtual router MAC address is never used as the source address in a link-level frame, then the station location is never learned, resulting in flooding of all packets sent to the virtual router. To improve the efficiency in this environment, the protocol should: 1) use the virtual router MAC address as the source in a packet sent by the Master to trigger station learning; 2) trigger a message immediately after transitioning to the Master to update the station learning; and 3) trigger periodic messages from the Master to maintain the station learning cache.
在多址LAN上发送IPvX数据包（即，发送IPv4或IPv6）需要从IPvX地址映射到MAC地址。在采用学习网桥的扩展LAN中使用虚拟路由器MAC地址会对发送到虚拟路由器的数据包的带宽开销产生显著影响。如果虚拟路由器MAC地址从未用作链路级帧中的源地址，则永远不会读入站点位置，从而导致发送到虚拟路由器的所有数据包泛滥。为了提高这种环境下的效率，该协议应该：1）使用虚拟路由器MAC地址作为主节点发送的数据包中的源来触发站点学习；2） 转换到主机后立即触发消息，以更新站点学习；以及3）触发来自主机的周期性消息，以维护站点学习缓存。
Sub-second detection of Master VRRP router failure is needed in both IPv4 and IPv6 environments. Earlier work proposed that sub-second operation was for IPv6; this specification leverages that earlier approach for IPv4 and IPv6.
IPv4和IPv6环境中都需要对主VRRP路由器故障进行亚秒级检测。早期的工作提出，亚秒级操作是针对IPv6的；此规范利用了IPv4和IPv6的早期方法。
One possible problematic scenario when using small VRRP_Advertisement_Intervals may occur when a router is delivering more packets onto the LAN than can be accommodated, and so a queue builds up in the router. It is possible that packets being transmitted onto the VRRP-protected LAN could see larger queueing delay than the smallest VRRP Advertisement_Interval. In this case, the Master_Down_Interval will be small enough so that normal queuing delays might cause a VRRP Backup to conclude that the Master is down, and therefore promote itself to Master. Very shortly afterwards, the delayed VRRP packets from the Master cause a switch back to Backup status. Furthermore, this process can repeat many times per second,
使用小VRRP_广告_间隔时，当路由器向LAN上传送的数据包超过其可容纳的数量时，可能会出现一种可能出现问题的情况，因此路由器中会出现队列。传输到受VRRP保护的LAN上的数据包可能比最小的VRRP广告间隔看到更大的排队延迟。在这种情况下，Master_Down_间隔将足够小，以便正常排队延迟可能会导致VRRP备份得出Master已关闭的结论，从而将其自身提升为Master。不久之后，来自主机的延迟VRRP数据包导致切换回备份状态。此外，该过程每秒可以重复多次，
causing significant disruption to traffic. To mitigate this problem, priority forwarding of VRRP packets should be considered. It should be possible for a VRRP Master to observe that this situation is occurring frequently and at least log the problem.
对交通造成重大干扰。为了缓解这个问题，应该考虑VRRP数据包的优先级转发。VRRP主机应能够观察到这种情况经常发生，并至少记录问题。
VRRP specifies an election protocol to provide the virtual router function described earlier. All protocol messaging is performed using either IPv4 or IPv6 multicast datagrams; thus, the protocol can operate over a variety of multiaccess LAN technologies supporting IPvX multicast. Each link of a VRRP virtual router has a single well-known MAC address allocated to it. This document currently only details the mapping to networks using the IEEE 802 48-bit MAC address. The virtual router MAC address is used as the source in all periodic VRRP messages sent by the Master router to enable bridge learning in an extended LAN.
VRRP指定一个选择协议，以提供前面描述的虚拟路由器功能。使用IPv4或IPv6多播数据报执行所有协议消息传递；因此，该协议可以在支持IPvX多播的多种多址LAN技术上运行。VRRP虚拟路由器的每条链路都分配有一个已知的MAC地址。本文档目前仅详细说明了使用IEEE 802 48位MAC地址到网络的映射。虚拟路由器MAC地址用作主路由器发送的所有定期VRRP消息的源，以在扩展LAN中启用网桥学习。
A virtual router is defined by its virtual router identifier (VRID) and a set of either IPv4 or IPv6 address(es). A VRRP router may associate a virtual router with its real address on an interface. The scope of each virtual router is restricted to a single LAN. A VRRP router may be configured with additional virtual router mappings and priority for virtual routers it is willing to back up. The mapping between the VRID and its IPvX address(es) must be coordinated among all VRRP routers on a LAN.
虚拟路由器由其虚拟路由器标识符（VRID）和一组IPv4或IPv6地址定义。VRRP路由器可将虚拟路由器与其接口上的真实地址相关联。每个虚拟路由器的作用域仅限于单个LAN。VRRP路由器可以配置额外的虚拟路由器映射和它愿意备份的虚拟路由器的优先级。必须在局域网上的所有VRRP路由器之间协调VRID与其IPvX地址之间的映射。
There is no restriction against reusing a VRID with a different address mapping on different LANs, nor is there a restriction against using the same VRID number for a set of IPv4 addresses and a set of IPv6 addresses; however, these are two different virtual routers.
不存在对在不同LAN上重用具有不同地址映射的VRID的限制，也不存在对在一组IPv4地址和一组IPv6地址中使用相同VRID号的限制；然而，这是两个不同的虚拟路由器。
To minimize network traffic, only the Master for each virtual router sends periodic VRRP Advertisement messages. A Backup router will not attempt to preempt the Master unless it has higher priority. This eliminates service disruption unless a more preferred path becomes available. It's also possible to administratively prohibit all preemption attempts. The only exception is that a VRRP router will always become Master of any virtual router associated with addresses it owns. If the Master becomes unavailable, then the highest-priority Backup will transition to Master after a short delay, providing a controlled transition of the virtual router responsibility with minimal service interruption.
为了最小化网络流量，只有每个虚拟路由器的主路由器定期发送VRRP广告消息。备份路由器不会尝试抢占主路由器，除非它具有更高的优先级。这将消除服务中断，除非有更首选的路径可用。还可以通过管理禁止所有抢占尝试。唯一的例外是，VRRP路由器将始终成为与其拥有的地址相关联的任何虚拟路由器的主机。如果主机变得不可用，则最高优先级的备份将在短时间延迟后过渡到主机，以最小的服务中断提供虚拟路由器责任的受控过渡。
The VRRP protocol design provides rapid transition from Backup to Master to minimize service interruption and incorporates optimizations that reduce protocol complexity while guaranteeing
VRRP协议设计提供了从备份到主备份的快速过渡，以最大限度地减少服务中断，并采用了一些优化，在保证安全性的同时降低了协议复杂性
controlled Master transition for typical operational scenarios. The optimizations result in an election protocol with minimal runtime state requirements, minimal active protocol states, and a single message type and sender. The typical operational scenarios are defined to be two redundant routers and/or distinct path preferences among each router. A side effect when these assumptions are violated (i.e., more than two redundant paths, all with equal preference) is that duplicate packets may be forwarded for a brief period during Master election. However, the typical scenario assumptions are likely to cover the vast majority of deployments, loss of the Master router is infrequent, and the expected duration in Master election convergence is quite small ( << 1 second ). Thus, the VRRP optimizations represent significant simplifications in the protocol design while incurring an insignificant probability of brief network degradation.
典型操作场景的受控主转换。优化的结果是选举协议具有最低的运行时状态要求、最低的活动协议状态以及单一的消息类型和发送方。典型的操作场景定义为两个冗余路由器和/或每个路由器之间的不同路径偏好。当违反这些假设时（即，两条以上的冗余路径，所有路径具有相同的优先权）的副作用是，在主选择期间，重复数据包可能会被转发一小段时间。然而，典型的场景假设可能涵盖绝大多数部署，主路由器的丢失很少，并且主选择收敛的预期持续时间非常小（<<1秒）。因此，VRRP优化代表了协议设计中的重大简化，同时导致短暂网络退化的可能性很小。
The following figure shows a simple network with two VRRP routers implementing one virtual router.
下图显示了一个简单的网络，其中两个VRRP路由器实现一个虚拟路由器。
+-----------+ +-----------+
| Rtr1 | | Rtr2 |
|(MR VRID=1)| |(BR VRID=1)|
| | | |
VRID=1 +-----------+ +-----------+
IPvX A--------->* *<---------IPvX B
| |
| |
----------------+------------+-----+----------+----------+----------+--
^ ^ ^ ^
| | | |
default rtr IPvX addrs-------> (IPvX A) (IPvX A) (IPvX A) (IPvX A)
| | | |
IPvX H1->* IpvX H2->* IPvX H3->* IpvX H4->*
+--+--+ +--+--+ +--+--+ +--+--+
| H1 | | H2 | | H3 | | H4 |
+-----+ +-----+ +--+--+ +--+--+
Legend:
--+---+---+-- = Ethernet, Token Ring, or FDDI
H = Host computer
MR = Master Router
BR = Backup Router
* = IPvX Address; X is 4 everywhere in IPv4 case
X is 6 everywhere in IPv6 case
(IPvX) = default router for hosts
+-----------+ +-----------+
| Rtr1 | | Rtr2 |
|(MR VRID=1)| |(BR VRID=1)|
| | | |
VRID=1 +-----------+ +-----------+
IPvX A--------->* *<---------IPvX B
| |
| |
----------------+------------+-----+----------+----------+----------+--
^ ^ ^ ^
| | | |
default rtr IPvX addrs-------> (IPvX A) (IPvX A) (IPvX A) (IPvX A)
| | | |
IPvX H1->* IpvX H2->* IPvX H3->* IpvX H4->*
+--+--+ +--+--+ +--+--+ +--+--+
| H1 | | H2 | | H3 | | H4 |
+-----+ +-----+ +--+--+ +--+--+
Legend:
--+---+---+-- = Ethernet, Token Ring, or FDDI
H = Host computer
MR = Master Router
BR = Backup Router
* = IPvX Address; X is 4 everywhere in IPv4 case
X is 6 everywhere in IPv6 case
(IPvX) = default router for hosts
Eliminating all mention of VRRP (VRID=1) from the figure above leaves it as a typical deployment.
从上图中删除所有提及VRRP（VRID=1）的内容，使其成为典型的部署。
In the IPv4 case (that is, IPvX is IPv4 everywhere in the figure), each router is permanently assigned an IPv4 address on the LAN interface (Rtr1 is assigned IPv4 A and Rtr2 is assigned IPv4 B), and each host installs a static default route through one of the routers (in this example they all use Rtr1's IPv4 A).
在IPv4情况下（即，图中IPvX在任何地方都是IPv4），每个路由器在LAN接口上被永久分配一个IPv4地址（Rtr1被分配到IPv4 A，Rtr2被分配到IPv4 B），并且每个主机通过一个路由器安装一个静态默认路由（在本例中，它们都使用Rtr1的IPv4 A）。
In the IPv6 case (that is, IPvX is IPv6 everywhere in the figure), each router has a link-local IPv6 address on the LAN interface (Rtr1 is assigned IPv6 Link-Local A and Rtr2 is assigned IPv6 Link-Local B), and each host learns a default route from Router Advertisements through one of the routers (in this example, they all use Rtr1's IPv6 Link-Local A).
在IPv6情况下（即，图中IPvX在任何地方都是IPv6），每个路由器在LAN接口上都有一个链路本地IPv6地址（Rtr1被分配到IPv6链路本地a，Rtr2被分配到IPv6链路本地B），并且每个主机通过一个路由器从路由器公告中学习默认路由（在本例中，它们都使用Rtr1的IPv6本地链路）。
Moving to an IPv4 VRRP environment, each router has the exact same permanently assigned IPv4 address. Rtr1 is said to be the IPv4 address owner of IPv4 A, and Rtr2 is the IPv4 address owner of IPv4 B. A virtual router is then defined by associating a unique identifier (the virtual router ID) with the address owned by a router.
移动到IPv4 VRRP环境，每个路由器都具有完全相同的永久分配IPv4地址。Rtr1被称为IPv4 A的IPv4地址所有者，Rtr2是IPv4 B的IPv4地址所有者。然后，通过将唯一标识符（虚拟路由器ID）与路由器拥有的地址相关联来定义虚拟路由器。
Moving to an IPv6 VRRP environment, each router has the exact same Link-Local IPv6 address. Rtr1 is said to be the IPv6 address owner of IPv6 A, and Rtr2 is the IPv6 address owner of IPv6 B. A virtual router is then defined by associating a unique identifier (the virtual router ID) with the address owned by a router.
移动到IPv6 VRRP环境，每个路由器都具有完全相同的链路本地IPv6地址。Rtr1被称为IPv6 A的IPv6地址所有者，Rtr2是IPv6 B的IPv6地址所有者。然后通过将唯一标识符（虚拟路由器ID）与路由器拥有的地址相关联来定义虚拟路由器。
Finally, in both the IPv4 and IPv6 cases, the VRRP protocol manages virtual router failover to a Backup router.
最后，在IPv4和IPv6情况下，VRRP协议管理到备份路由器的虚拟路由器故障切换。
The IPv4 example above shows a virtual router configured to cover the IPv4 address owned by Rtr1 (VRID=1, IPv4_Address=A). When VRRP is enabled on Rtr1 for VRID=1, it will assert itself as Master, with priority = 255, since it is the IP address owner for the virtual router IP address. When VRRP is enabled on Rtr2 for VRID=1, it will transition to Backup, with priority = 100 (the default priority is 100), since it is not the IPv4 address owner. If Rtr1 should fail, then the VRRP protocol will transition Rtr2 to Master, temporarily taking over forwarding responsibility for IPv4 A to provide uninterrupted service to the hosts. When Rtr1 returns to service, it will re-assert itself as Master.
上面的IPv4示例显示了一个虚拟路由器，它被配置为覆盖Rtr1拥有的IPv4地址（VRID=1，IPv4_地址=a）。当VRRP在Rtr1上为VRID=1启用时，它将断言自己为主机，优先级为255，因为它是虚拟路由器IP地址的IP地址所有者。当在Rtr2上为VRID=1启用VRRP时，它将转换为备份，优先级为100（默认优先级为100），因为它不是IPv4地址所有者。如果Rtr1失败，则VRRP协议将Rtr2转换为主协议，临时接管IPv4 A的转发责任，以向主机提供不间断服务。当Rtr1返回服务时，它将重新声明自己为主服务器。
The IPv6 example above shows a virtual router configured to cover the IPv6 address owned by Rtr1 (VRID=1, IPv6_Address=A). When VRRP is enabled on Rtr1 for VRID=1, it will assert itself as Master, with priority = 255, since it is the IPv6 address owner for the virtual
上面的IPv6示例显示了配置为覆盖Rtr1拥有的IPv6地址的虚拟路由器（VRID=1，IPv6_地址=a）。当在Rtr1上为VRID=1启用VRRP时，它将声明自己为主机，优先级为255，因为它是虚拟机的IPv6地址所有者
router IPv6 address. When VRRP is enabled on Rtr2 for VRID=1, it will transition to Backup, with priority = 100 (the default priority is 100), since it is not the IPv6 address owner. If Rtr1 should fail, then the VRRP protocol will transition Rtr2 to Master, temporarily taking over forwarding responsibility for IPv6 A to provide uninterrupted service to the hosts.
路由器IPv6地址。当在Rtr2上为VRID=1启用VRRP时，它将转换为备份，优先级为100（默认优先级为100），因为它不是IPv6地址所有者。如果Rtr1失败，则VRRP协议将Rtr2转换为主协议，临时接管IPv6 A的转发责任，以向主机提供不间断服务。
Note that in both cases, in this example IPvX B is not backed up; it is only used by Rtr2 as its interface address. In order to back up IPvX B, a second virtual router must be configured. This is shown in the next section.
注意，在这两种情况下，在本例中，IPvX B未备份；它仅由Rtr2用作其接口地址。为了备份IPvX B，必须配置第二个虚拟路由器。这将在下一节中显示。
The following figure shows a configuration with two virtual routers with the hosts splitting their traffic between them.
下图显示了两个虚拟路由器的配置，其中主机在两个虚拟路由器之间分配流量。
+-----------+ +-----------+
| Rtr1 | | Rtr2 |
|(MR VRID=1)| |(BR VRID=1)|
|(BR VRID=2)| |(MR VRID=2)|
VRID=1 +-----------+ +-----------+ VRID=2
IPvX A -------->* *<---------- IPvX B
| |
| |
----------------+------------+-----+----------+----------+----------+--
^ ^ ^ ^
| | | |
default rtr IPvX addrs -----> (IPvX A) (IPvX A) (IPvX B) (IPvX B)
| | | |
IPvX H1->* IpvX H2->* IPvX H3->* IpvX H4->*
+--+--+ +--+--+ +--+--+ +--+--+
| H1 | | H2 | | H3 | | H4 |
+-----+ +-----+ +--+--+ +--+--+
Legend:
---+---+---+-- = Ethernet, Token Ring, or FDDI
H = Host computer
MR = Master Router
BR = Backup Router
* = IPvX Address; X is 4 everywhere in IPv4 case
X is 6 everywhere in IPv6 case
(IPvX) = default router for hosts
+-----------+ +-----------+
| Rtr1 | | Rtr2 |
|(MR VRID=1)| |(BR VRID=1)|
|(BR VRID=2)| |(MR VRID=2)|
VRID=1 +-----------+ +-----------+ VRID=2
IPvX A -------->* *<---------- IPvX B
| |
| |
----------------+------------+-----+----------+----------+----------+--
^ ^ ^ ^
| | | |
default rtr IPvX addrs -----> (IPvX A) (IPvX A) (IPvX B) (IPvX B)
| | | |
IPvX H1->* IpvX H2->* IPvX H3->* IpvX H4->*
+--+--+ +--+--+ +--+--+ +--+--+
| H1 | | H2 | | H3 | | H4 |
+-----+ +-----+ +--+--+ +--+--+
Legend:
---+---+---+-- = Ethernet, Token Ring, or FDDI
H = Host computer
MR = Master Router
BR = Backup Router
* = IPvX Address; X is 4 everywhere in IPv4 case
X is 6 everywhere in IPv6 case
(IPvX) = default router for hosts
In the IPv4 example above (that is, IPvX is IPv4 everywhere in the figure), half of the hosts have configured a static route through Rtr1's IPv4 A, and half are using Rtr2's IPv4 B. The configuration of virtual router VRID=1 is exactly the same as in the first example (see Section 4.1), and a second virtual router has been added to
在上面的IPv4示例中（即，IPvX在图中的任何位置都是IPv4），一半的主机通过Rtr1的IPv4 a配置了静态路由，一半使用Rtr2的IPv4 B。虚拟路由器VRID=1的配置与第一个示例中的配置完全相同（参见第4.1节），第二个虚拟路由器已添加到
cover the IPv4 address owned by Rtr2 (VRID=2, IPv4_Address=B). In this case, Rtr2 will assert itself as Master for VRID=2 while Rtr1 will act as a Backup. This scenario demonstrates a deployment providing load splitting when both routers are available, while providing full redundancy for robustness.
覆盖Rtr2拥有的IPv4地址（VRID=2，IPv4\U地址=B）。在这种情况下，Rtr2将自己声明为VRID=2的主控，而Rtr1将充当备份。此场景演示了在两个路由器都可用时提供负载拆分的部署，同时为健壮性提供完全冗余。
In the IPv6 example above (that is, IPvX is IPv6 everywhere in the figure), half of the hosts have learned a default route through Rtr1's IPv6 A, and half are using Rtr2's IPv6 B. The configuration of virtual router VRID=1 is exactly the same as in the first example (see Section 4.1), and a second virtual router has been added to cover the IPv6 address owned by Rtr2 (VRID=2, IPv6_Address=B). In this case, Rtr2 will assert itself as Master for VRID=2 while Rtr1 will act as a Backup. This scenario demonstrates a deployment providing load splitting when both routers are available, while providing full redundancy for robustness.
在上面的IPv6示例中（即图中IPvX在任何地方都是IPv6），一半的主机通过Rtr1的IPv6 a学习了默认路由，一半使用Rtr2的IPv6 B。虚拟路由器VRID=1的配置与第一个示例中的配置完全相同（见第4.1节），并且添加了第二个虚拟路由器以覆盖Rtr2拥有的IPv6地址（VRID=2，IPv6_地址=B）。在这种情况下，Rtr2将自己声明为VRID=2的主控，而Rtr1将充当备份。此场景演示了在两个路由器都可用时提供负载拆分的部署，同时为健壮性提供完全冗余。
Note that the details of load balancing are out of scope of this document. However, in a case where the servers need different weights, it may not make sense to rely on router advertisements alone to balance the host load between the routers.
请注意，负载平衡的详细信息超出了本文档的范围。然而，在服务器需要不同权重的情况下，仅依靠路由器广告来平衡路由器之间的主机负载可能没有意义。
The purpose of the VRRP packet is to communicate to all VRRP routers the priority and the state of the Master router associated with the VRID.
VRRP包的目的是向所有VRRP路由器传达与VRID相关联的主路由器的优先级和状态。
When VRRP is protecting an IPv4 address, VRRP packets are sent encapsulated in IPv4 packets. They are sent to the IPv4 multicast address assigned to VRRP.
当VRRP保护IPv4地址时，VRRP数据包被封装在IPv4数据包中发送。它们被发送到分配给VRRP的IPv4多播地址。
When VRRP is protecting an IPv6 address, VRRP packets are sent encapsulated in IPv6 packets. They are sent to the IPv6 multicast address assigned to VRRP.
当VRRP保护IPv6地址时，VRRP数据包被封装在IPv6数据包中发送。它们被发送到分配给VRRP的IPv6多播地址。
This section defines the format of the VRRP packet and the relevant fields in the IP header.
本节定义了VRRP数据包的格式以及IP报头中的相关字段。
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Fields or IPv6 Fields |
... ...
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Type | Virtual Rtr ID| Priority |Count IPvX Addr|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|(rsvd) | Max Adver Int | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| IPvX Address(es) |
+ +
+ +
+ +
+ +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Fields or IPv6 Fields |
... ...
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Type | Virtual Rtr ID| Priority |Count IPvX Addr|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|(rsvd) | Max Adver Int | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| IPvX Address(es) |
+ +
+ +
+ +
+ +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This is the primary IPv4 address of the interface the packet is being sent from.
这是从中发送数据包的接口的主IPv4地址。
The IPv4 multicast address as assigned by the IANA for VRRP is:
IANA为VRRP分配的IPv4多播地址为：
224.0.0.18
224.0.0.18
This is a link-local scope multicast address. Routers MUST NOT forward a datagram with this destination address, regardless of its TTL.
这是一个链路本地作用域多播地址。路由器不得转发具有此目标地址的数据报，无论其TTL如何。
The TTL MUST be set to 255. A VRRP router receiving a packet with the TTL not equal to 255 MUST discard the packet.
TTL必须设置为255。接收TTL不等于255的数据包的VRRP路由器必须丢弃该数据包。
The IPv4 protocol number assigned by the IANA for VRRP is 112 (decimal).
IANA为VRRP分配的IPv4协议号为112（十进制）。
This is the IPv6 link-local address of the interface the packet is being sent from.
这是发送数据包的接口的IPv6链路本地地址。
The IPv6 multicast address assigned by the IANA for VRRP is:
IANA为VRRP分配的IPv6多播地址为：
FF02:0:0:0:0:0:0:12
FF02:0:0:0:0:0:0:12
This is a link-local scope multicast address. Routers MUST NOT forward a datagram with this destination address, regardless of its Hop Limit.
这是一个链路本地作用域多播地址。路由器不得转发具有此目标地址的数据报，无论其跳数限制如何。
The Hop Limit MUST be set to 255. A VRRP router receiving a packet with the Hop Limit not equal to 255 MUST discard the packet.
跃点限制必须设置为255。接收跃点限制不等于255的数据包的VRRP路由器必须丢弃该数据包。
The IPv6 Next Header protocol assigned by the IANA for VRRP is 112 (decimal).
IANA为VRRP分配的IPv6下一个报头协议为112（十进制）。
The version field specifies the VRRP protocol version of this packet. This document defines version 3.
版本字段指定此数据包的VRRP协议版本。本文档定义了版本3。
The type field specifies the type of this VRRP packet. The only packet type defined in this version of the protocol is:
类型字段指定此VRRP数据包的类型。本协议版本中定义的唯一数据包类型为：
1 ADVERTISEMENT
1广告
A packet with unknown type MUST be discarded.
必须丢弃类型未知的数据包。
The Virtual Rtr ID field identifies the virtual router this packet is reporting status for.
Virtual Rtr ID字段标识此数据包报告状态的虚拟路由器。
The priority field specifies the sending VRRP router's priority for the virtual router. Higher values equal higher priority. This field is an 8-bit unsigned integer field.
优先级字段为虚拟路由器指定发送VRRP路由器的优先级。值越高，优先级越高。此字段是一个8位无符号整数字段。
The priority value for the VRRP router that owns the IPvX address associated with the virtual router MUST be 255 (decimal).
拥有与虚拟路由器关联的IPvX地址的VRRP路由器的优先级值必须为255（十进制）。
VRRP routers backing up a virtual router MUST use priority values between 1-254 (decimal). The default priority value for VRRP routers backing up a virtual router is 100 (decimal).
备份虚拟路由器的VRRP路由器必须使用1-254（十进制）之间的优先级值。备份虚拟路由器的VRRP路由器的默认优先级值为100（十进制）。
The priority value zero (0) has special meaning, indicating that the current Master has stopped participating in VRRP. This is used to trigger Backup routers to quickly transition to Master without having to wait for the current Master to time out.
优先级值0（0）具有特殊意义，表示当前主机已停止参与VRRP。这用于触发备份路由器快速过渡到主路由器，而无需等待当前主路由器超时。
This is the number of either IPv4 addresses or IPv6 addresses contained in this VRRP advertisement. The minimum value is 1.
这是此VRRP播发中包含的IPv4地址或IPv6地址数。最小值为1。
This field MUST be set to zero on transmission and ignored on reception.
此字段在传输时必须设置为零，在接收时必须忽略。
The Maximum Advertisement Interval is a 12-bit field that indicates the time interval (in centiseconds) between ADVERTISEMENTS. The default is 100 centiseconds (1 second).
最大播发间隔是一个12位字段，表示播发之间的时间间隔（以厘米为单位）。默认值为100厘米秒（1秒）。
Note that higher-priority Master routers with slower transmission rates than their Backup routers are unstable. This is because low-priority nodes configured to faster rates could come online and decide they should be Masters before they have heard anything from the higher-priority Master with a slower rate. When this happens, it is temporary: once the lower-priority node does hear from the higher-priority Master, it will relinquish mastership.
请注意，传输速率比备份路由器慢的高优先级主路由器是不稳定的。这是因为配置为更快速率的低优先级节点可能会在线，并在听到来自更高优先级、更慢速率的主节点的任何消息之前决定它们应该是主节点。当这种情况发生时，它是暂时的：一旦低优先级节点确实收到高优先级主节点的消息，它将放弃主节点。
The checksum field is used to detect data corruption in the VRRP message.
校验和字段用于检测VRRP消息中的数据损坏。
The checksum is the 16-bit one's complement of the one's complement sum of the entire VRRP message starting with the version field and a "pseudo-header" as defined in Section 8.1 of [RFC2460]. The next header field in the "pseudo-header" should be set to 112 (decimal) for VRRP. For computing the checksum, the checksum field is set to zero. See RFC1071 for more detail [RFC1071].
校验和是以版本字段和[RFC2460]第8.1节中定义的“伪标头”开始的整个VRRP消息的16位一补一补。对于VRRP，“伪标头”中的下一个标头字段应设置为112（十进制）。为了计算校验和，校验和字段设置为零。有关更多详细信息，请参见RFC1071[RFC1071]。
This refers to one or more IPvX addresses associated with the virtual router. The number of addresses included is specified in the "Count IP Addr" field. These fields are used for troubleshooting misconfigured routers. If more than one address is sent, it is recommended that all routers be configured to send these addresses in the same order to make it easier to do this comparison.
这是指与虚拟路由器关联的一个或多个IPvX地址。包含的地址数在“计数IP地址”字段中指定。这些字段用于对配置错误的路由器进行故障排除。如果发送多个地址，建议将所有路由器配置为以相同的顺序发送这些地址，以便于进行比较。
For IPv4 addresses, this refers to one or more IPv4 addresses that are backed up by the virtual router.
对于IPv4地址，这是指由虚拟路由器备份的一个或多个IPv4地址。
For IPv6, the first address must be the IPv6 link-local address associated with the virtual router.
对于IPv6，第一个地址必须是与虚拟路由器关联的IPv6链路本地地址。
This field contains either one or more IPv4 addresses, or one or more IPv6 addresses, that is, IPv4 and IPv6 MUST NOT both be carried in one IPvX Address field.
此字段包含一个或多个IPv4地址，或一个或多个IPv6地址，即IPv4和IPv6不能同时包含在一个IPvX地址字段中。
VRID Virtual Router Identifier. Configurable item in the range 1-255 (decimal). There is no default.
虚拟路由器标识符。范围为1-255（十进制）的可配置项。没有默认设置。
Priority Priority value to be used by this VRRP router in Master election for this virtual router. The value of 255 (decimal) is reserved for the router that owns the IPvX address associated with the virtual router. The value of 0 (zero) is reserved for the Master router to indicate it is releasing responsibility for the virtual router. The range 1-254 (decimal) is available for VRRP routers backing up the virtual router. Higher values indicate higher priorities. The default value is 100 (decimal).
此VRRP路由器在此虚拟路由器的主选择中使用的优先级值。255（十进制）的值是为拥有与虚拟路由器关联的IPvX地址的路由器保留的。0（零）的值保留给主路由器，以表示它正在释放对虚拟路由器的责任。范围1-254（十进制）可用于备份虚拟路由器的VRRP路由器。值越高表示优先级越高。默认值为100（十进制）。
IPv4_Addresses One or more IPv4 addresses associated with this virtual router. Configured item with no default.
IPv4\地址与此虚拟路由器关联的一个或多个IPv4地址。配置的项目没有默认值。
IPv6_Addresses One or more IPv6 addresses associated with this virtual router. Configured item with no default. The first address must be the Link-Local address associated with the virtual router.
IPv6\地址与此虚拟路由器关联的一个或多个IPv6地址。配置的项目没有默认值。第一个地址必须是与虚拟路由器关联的链路本地地址。
Advertisement_Interval Time interval between ADVERTISEMENTS (centiseconds). Default is 100 centiseconds (1 second).
广告间隔广告之间的时间间隔（厘米秒）。默认值为100厘米秒（1秒）。
Master_Adver_Interval Advertisement interval contained in ADVERTISEMENTS received from the Master (centiseconds). This value is saved by virtual routers in the Backup state and used to compute Skew_Time and Master_Down_Interval. The initial value is the same as Advertisement_Interval.
主机广告间隔从主机接收的广告中包含的广告间隔（厘米秒）。此值由处于备份状态的虚拟路由器保存，并用于计算倾斜时间和主下降间隔。初始值与U间隔相同。
Skew_Time Time to skew Master_Down_Interval in centiseconds. Calculated as
倾斜时间以厘米为单位倾斜主控向下间隔的时间。计算为
(((256 - priority) * Master_Adver_Interval) / 256)
(((256 - priority) * Master_Adver_Interval) / 256)
Master_Down_Interval Time interval for Backup to declare Master down (centiseconds). Calculated as
主控停机时间间隔备份宣布主控停机的时间间隔（厘米秒）。计算为
(3 * Master_Adver_Interval) + Skew_time
（3*主/辅间隔）+倾斜时间
Preempt_Mode Controls whether a (starting or restarting) higher-priority Backup router preempts a lower-priority Master router. Values are True to allow preemption and False to prohibit preemption. Default is True.
抢占模式控制（启动或重新启动）高优先级备份路由器是否抢占低优先级主路由器。值为True表示允许抢占，值为False表示禁止抢占。默认值为True。
Note: The exception is that the router that owns the IPvX address associated with the virtual router always preempts, independent of the setting of this flag.
注意：例外情况是，拥有与虚拟路由器关联的IPvX地址的路由器总是抢占，与此标志的设置无关。
Accept_Mode Controls whether a virtual router in Master state will accept packets addressed to the address owner's IPvX address as its own if it is not the IPvX address owner. The default is False. Deployments that rely on, for example, pinging the address owner's IPvX address may wish to configure Accept_Mode to True.
Accept_模式控制处于主状态的虚拟路由器是否将地址所有者的IPvX地址的数据包作为自己的数据包接受（如果它不是IPvX地址所有者）。默认值为False。例如，依赖ping地址所有者的IPvX地址的部署可能希望将Accept_Mode配置为True。
Note: IPv6 Neighbor Solicitations and Neighbor Advertisements MUST NOT be dropped when Accept_Mode is False.
注意：当Accept_Mode为False时，不得删除IPv6邻居请求和邻居播发。
Virtual_Router_MAC_Address The MAC address used for the source MAC address in VRRP advertisements and advertised in ARP responses as the MAC address to use for IP_Addresses.
虚拟路由器MAC地址在VRRP广告中用作源MAC地址的MAC地址，在ARP响应中用作IP地址的MAC地址。
Master_Down_Timer Timer that fires when ADVERTISEMENT has not been heard for Master_Down_Interval.
Master_Down_定时器，当尚未听到Master_Down_间隔的广告时触发。
Adver_Timer Timer that fires to trigger sending of ADVERTISEMENT based on Advertisement_Interval.
Adver_定时器，根据广告间隔触发广告发送。
+---------------+
+--------->| |<-------------+
| | Initialize | |
| +------| |----------+ |
| | +---------------+ | |
| | | |
| V V |
+---------------+ +---------------+
| |---------------------->| |
| Master | | Backup |
| |<----------------------| |
+---------------+ +---------------+
+---------------+
+--------->| |<-------------+
| | Initialize | |
| +------| |----------+ |
| | +---------------+ | |
| | | |
| V V |
+---------------+ +---------------+
| |---------------------->| |
| Master | | Backup |
| |<----------------------| |
+---------------+ +---------------+
In the state descriptions below, the state names are identified by {state-name}, and the packets are identified by all-uppercase characters.
在下面的状态描述中，状态名称由{state name}标识，数据包由所有大写字符标识。
A VRRP router implements an instance of the state machine for each virtual router election it is participating in.
VRRP路由器为其参与的每个虚拟路由器选择实现一个状态机实例。
The purpose of this state is to wait for a Startup event, that is, an implementation-defined mechanism that initiates the protocol once it has been configured. The configuration mechanism is out of scope of this specification.
此状态的目的是等待启动事件，即一种实现定义的机制，该机制在配置协议后启动协议。配置机制超出了本规范的范围。
(100) If a Startup event is received, then:
（100）如果收到启动事件，则：
(105) - If the Priority = 255 (i.e., the router owns the IPvX address associated with the virtual router), then:
（105）-如果优先级=255（即，路由器拥有与虚拟路由器关联的IPvX地址），则：
(110) + Send an ADVERTISEMENT
（110）+发送广告
(115) + If the protected IPvX address is an IPv4 address, then:
（115）+如果受保护的IPvX地址是IPv4地址，则：
(120) * Broadcast a gratuitous ARP request containing the virtual router MAC address for each IP address associated with the virtual router.
（120）*广播免费ARP请求，其中包含与虚拟路由器相关的每个IP地址的虚拟路由器MAC地址。
(125) + else // IPv6
(125) + else // IPv6
(130) * For each IPv6 address associated with the virtual router, send an unsolicited ND Neighbor Advertisement with
（130）*对于与虚拟路由器关联的每个IPv6地址，使用
the Router Flag (R) set, the Solicited Flag (S) unset, the Override flag (O) set, the target address set to the IPv6 address of the virtual router, and the target link-layer address set to the virtual router MAC address.
路由器标志（R）设置、请求标志（S）未设置、覆盖标志（O）设置、目标地址设置为虚拟路由器的IPv6地址、目标链路层地址设置为虚拟路由器MAC地址。
(135) +endif // was protected addr IPv4?
(135) +endif // was protected addr IPv4?
(140) + Set the Adver_Timer to Advertisement_Interval
（140）+将广告计时器设置为广告间隔
(145) + Transition to the {Master} state
(145) + Transition to the {Master} state
(150) - else // rtr does not own virt addr
(150) - else // rtr does not own virt addr
(155) + Set Master_Adver_Interval to Advertisement_Interval
（155）+将主广告间隔设置为广告间隔
(160) + Set the Master_Down_Timer to Master_Down_Interval
（160）+将Master_Down_定时器设置为Master_Down_间隔
(165) + Transition to the {Backup} state
(165) + Transition to the {Backup} state
(170) -endif // priority was not 255
(170) -endif // priority was not 255
(175) endif // startup event was recv
（175）endif//启动事件为recv
The purpose of the {Backup} state is to monitor the availability and state of the Master router.
{Backup}状态的目的是监视主路由器的可用性和状态。
(300) While in this state, a VRRP router MUST do the following:
（300）在此状态下，VRRP路由器必须执行以下操作：
(305) - If the protected IPvX address is an IPv4 address, then:
（305）-如果受保护的IPvX地址是IPv4地址，则：
(310) + MUST NOT respond to ARP requests for the IPv4 address(es) associated with the virtual router.
（310）+不得响应与虚拟路由器关联的IPv4地址的ARP请求。
(315) - else // protected addr is IPv6
(315) - else // protected addr is IPv6
(320) + MUST NOT respond to ND Neighbor Solicitation messages for the IPv6 address(es) associated with the virtual router.
（320）+不得响应与虚拟路由器关联的IPv6地址的ND邻居请求消息。
(325) + MUST NOT send ND Router Advertisement messages for the virtual router.
（325）+不得为虚拟路由器发送ND路由器广告消息。
(330) -endif // was protected addr IPv4?
(330) -endif // was protected addr IPv4?
(335) - MUST discard packets with a destination link-layer MAC address equal to the virtual router MAC address.
（335）-必须丢弃目标链路层MAC地址等于虚拟路由器MAC地址的数据包。
(340) - MUST NOT accept packets addressed to the IPvX address(es) associated with the virtual router.
（340）-不得接受发往与虚拟路由器关联的IPvX地址的数据包。
(345) - If a Shutdown event is received, then:
（345）-如果收到停机事件，则：
(350) + Cancel the Master_Down_Timer
（350）+取消主定时器
(355) + Transition to the {Initialize} state
(355) + Transition to the {Initialize} state
(360) -endif // shutdown recv
(360) -endif // shutdown recv
(365) - If the Master_Down_Timer fires, then:
（365）-如果主定时器触发，则：
(370) + Send an ADVERTISEMENT
（370）+发送广告
(375) + If the protected IPvX address is an IPv4 address, then:
（375）+如果受保护的IPvX地址是IPv4地址，则：
(380) * Broadcast a gratuitous ARP request on that interface containing the virtual router MAC address for each IPv4 address associated with the virtual router.
（380）*在该接口上广播一个免费的ARP请求，其中包含与虚拟路由器关联的每个IPv4地址的虚拟路由器MAC地址。
(385) + else // ipv6
(385) + else // ipv6
(390) * Compute and join the Solicited-Node multicast address [RFC4291] for the IPv6 address(es) associated with the virtual router.
（390）*计算并加入与虚拟路由器关联的IPv6地址的请求节点多播地址[RFC4291]。
(395) * For each IPv6 address associated with the virtual router, send an unsolicited ND Neighbor Advertisement with the Router Flag (R) set, the Solicited Flag (S) unset, the Override flag (O) set, the target address set to the IPv6 address of the virtual router, and the target link-layer address set to the virtual router MAC address.
（395）*对于与虚拟路由器关联的每个IPv6地址，发送一个未经请求的ND邻居通告，其中路由器标志（R）设置、请求标志（S）未设置、覆盖标志（O）设置、目标地址设置为虚拟路由器的IPv6地址、目标链路层地址设置为虚拟路由器MAC地址。
(400) +endif // was protected addr ipv4?
(400) +endif // was protected addr ipv4?
(405) + Set the Adver_Timer to Advertisement_Interval
（405）+将广告计时器设置为广告间隔
(410) + Transition to the {Master} state
(410) + Transition to the {Master} state
(415) -endif // Master_Down_Timer fired
(415) -endif // Master_Down_Timer fired
(420) - If an ADVERTISEMENT is received, then:
（420）-如果收到广告，则：
(425) + If the Priority in the ADVERTISEMENT is zero, then:
（425）+如果广告中的优先级为零，则：
(430) * Set the Master_Down_Timer to Skew_Time
（430）*将主定时器设置为倾斜时间
(440) + else // priority non-zero
(440) + else // priority non-zero
(445) * If Preempt_Mode is False, or if the Priority in the ADVERTISEMENT is greater than or equal to the local Priority, then:
（445）*如果抢占_模式为假，或者如果广告中的优先级大于或等于本地优先级，则：
(450) @ Set Master_Adver_Interval to Adver Interval contained in the ADVERTISEMENT
（450）@Set Master_Adver_Interval为广告中包含的Adver Interval
(455) @ Recompute the Master_Down_Interval
（455）@重新计算主时间间隔
(460) @ Reset the Master_Down_Timer to Master_Down_Interval
（460）@将Master_Down_计时器重置为Master_Down_间隔
(465) * else // preempt was true or priority was less
(465) * else // preempt was true or priority was less
(470) @ Discard the ADVERTISEMENT
（470）@丢弃广告
(475) *endif // preempt test
(475) *endif // preempt test
(480) +endif // was priority zero?
(480) +endif // was priority zero?
(485) -endif // was advertisement recv?
(485) -endif // was advertisement recv?
(490) endwhile // Backup state
（490）结束时//备份状态
While in the {Master} state, the router functions as the forwarding router for the IPvX address(es) associated with the virtual router.
当处于{Master}状态时，路由器充当与虚拟路由器关联的IPvX地址的转发路由器。
Note that in the Master state, the Preempt_Mode Flag is not considered.
注意，在主状态下，不考虑Preempt_模式标志。
(600) While in this state, a VRRP router MUST do the following:
（600）在此状态下，VRRP路由器必须执行以下操作：
(605) - If the protected IPvX address is an IPv4 address, then:
（605）-如果受保护的IPvX地址是IPv4地址，则：
(610) + MUST respond to ARP requests for the IPv4 address(es) associated with the virtual router.
（610）+必须响应与虚拟路由器关联的IPv4地址的ARP请求。
(615) - else // ipv6
(615) - else // ipv6
(620) + MUST be a member of the Solicited-Node multicast address for the IPv6 address(es) associated with the virtual router.
（620）+必须是与虚拟路由器关联的IPv6地址的请求节点多播地址的成员。
(625) + MUST respond to ND Neighbor Solicitation message for the IPv6 address(es) associated with the virtual router.
（625）+必须响应与虚拟路由器关联的IPv6地址的ND邻居请求消息。
(630) ++ MUST send ND Router Advertisements for the virtual router.
（630）++必须为虚拟路由器发送ND路由器广告。
(635) ++ If Accept_Mode is False: MUST NOT drop IPv6 Neighbor Solicitations and Neighbor Advertisements.
（635）++如果接受_模式为False：不得丢弃IPv6邻居请求和邻居播发。
(640) +-endif // ipv4?
(640) +-endif // ipv4?
(645) - MUST forward packets with a destination link-layer MAC address equal to the virtual router MAC address.
（645）-必须转发目标链路层MAC地址等于虚拟路由器MAC地址的数据包。
(650) - MUST accept packets addressed to the IPvX address(es) associated with the virtual router if it is the IPvX address owner or if Accept_Mode is True. Otherwise, MUST NOT accept these packets.
（650）-如果是IPvX地址所有者或如果accept_模式为真，则必须接受发往与虚拟路由器关联的IPvX地址的数据包。否则，必须不接受这些数据包。
(655) - If a Shutdown event is received, then:
（655）-如果收到停机事件，则：
(660) + Cancel the Adver_Timer
（660）+取消Adver_计时器
(665) + Send an ADVERTISEMENT with Priority = 0
（665）+发送优先级为0的广告
(670) + Transition to the {Initialize} state
(670) + Transition to the {Initialize} state
(675) -endif // shutdown recv
(675) -endif // shutdown recv
(680) - If the Adver_Timer fires, then:
（680）-如果Adver_定时器启动，则：
(685) + Send an ADVERTISEMENT
发送广告
(690) + Reset the Adver_Timer to Advertisement_Interval
（690）+将广告计时器重置为广告间隔
(695) -endif // advertisement timer fired
(695) -endif // advertisement timer fired
(700) - If an ADVERTISEMENT is received, then:
（700）-如果收到广告，则：
(705) -+ If the Priority in the ADVERTISEMENT is zero, then:
（705）-+如果广告中的优先级为零，则：
(710) -* Send an ADVERTISEMENT
（710）——*发送广告
(715) -* Reset the Adver_Timer to Advertisement_Interval
（715）-*将广告计时器重置为广告间隔
(720) -+ else // priority was non-zero
(720) -+ else // priority was non-zero
(725) -* If the Priority in the ADVERTISEMENT is greater than the local Priority,
（725）——*如果广告中的优先级大于本地优先级，
(730) -* or
（730）——*或
(735) -* If the Priority in the ADVERTISEMENT is equal to the local Priority and the primary IPvX Address of the sender is greater than the local primary IPvX Address, then:
（735）——*如果播发中的优先级等于本地优先级，并且发送方的主IPvX地址大于本地主IPvX地址，则：
(740) -@ Cancel Adver_Timer
（740）-@取消Adver\u计时器
(745) -@ Set Master_Adver_Interval to Adver Interval contained in the ADVERTISEMENT
（745）——@将主辅间隔设置为播发中包含的辅间隔
(750) -@ Recompute the Skew_Time
（750）-重新计算倾斜时间
(755) @ Recompute the Master_Down_Interval
（755）@重新计算主时间间隔
(760) @ Set Master_Down_Timer to Master_Down_Interval
（760）@将Master_Down_定时器设置为Master_Down_间隔
(765) @ Transition to the {Backup} state
(765) @ Transition to the {Backup} state
(770) * else // new Master logic
(770) * else // new Master logic
(775) @ Discard ADVERTISEMENT
（775）@丢弃广告
(780) *endif // new Master detected
(780) *endif // new Master detected
(785) +endif // was priority zero?
(785) +endif // was priority zero?
(790) -endif // advert recv
(790) -endif // advert recv
(795) endwhile // in Master
（795）主控中的endwhile//
The following functions are performed when a VRRP packet is received:
当接收到VRRP数据包时，执行以下功能：
- If the received packet is an IPv4 packet, then:
- 如果收到的数据包是IPv4数据包，则：
+ MUST verify that the IPv4 TTL is 255.
+ 必须验证IPv4 TTL是否为255。
- else // ipv6 recv
- else//ipv6 recv
+ MUST verify that the IPv6 Hop Limit is 255.
+ 必须验证IPv6跃点限制是否为255。
-endif
-恩迪夫
- MUST verify that the VRRP version is 3.
- 必须验证VRRP版本是否为3。
- MUST verify that the received packet contains the complete VRRP packet (including fixed fields, and IPvX address).
- 必须验证收到的数据包是否包含完整的VRRP数据包（包括固定字段和IPvX地址）。
- MUST verify the VRRP checksum.
- 必须验证VRRP校验和。
- MUST verify that the VRID is configured on the receiving interface and the local router is not the IPvX address owner (Priority = 255 (decimal)).
- 必须验证在接收接口上配置了VRID，并且本地路由器不是IPvX地址所有者（优先级=255（十进制））。
If any one of the above checks fails, the receiver MUST discard the packet, SHOULD log the event, and MAY indicate via network management that an error occurred.
如果上述任何一项检查失败，接收方必须丢弃数据包，记录事件，并可通过网络管理指示发生错误。
- MAY verify that "Count IPvX Addrs" and the list of IPvX address(es) match the IPvX Address(es) configured for the VRID.
- 可验证“计数IPvX地址”和IPvX地址列表是否与为VRID配置的IPvX地址匹配。
If the above check fails, the receiver SHOULD log the event and MAY indicate via network management that a misconfiguration was detected.
如果上述检查失败，接收器应记录事件，并可通过网络管理指示检测到错误配置。
The following operations MUST be performed when transmitting a VRRP packet:
传输VRRP数据包时，必须执行以下操作：
- Fill in the VRRP packet fields with the appropriate virtual router configuration state
- 用适当的虚拟路由器配置状态填写VRRP数据包字段
- Compute the VRRP checksum
- 计算VRRP校验和
- If the protected address is an IPv4 address, then:
- 如果受保护的地址是IPv4地址，则：
+ Set the source MAC address to virtual router MAC Address
+ 将源MAC地址设置为虚拟路由器MAC地址
+ Set the source IPv4 address to interface primary IPv4 address
+ 将源IPv4地址设置为接口主IPv4地址
- else // ipv6
- else//ipv6
+ Set the source MAC address to virtual router MAC Address
+ 将源MAC地址设置为虚拟路由器MAC地址
+ Set the source IPv6 address to interface link-local IPv6 address
+ 将源IPv6地址设置为接口链路本地IPv6地址
-endif
-恩迪夫
- Set the IPvX protocol to VRRP
- 将IPvX协议设置为VRRP
- Send the VRRP packet to the VRRP IPvX multicast group
- 将VRRP数据包发送到VRRP IPvX多播组
Note: VRRP packets are transmitted with the virtual router MAC address as the source MAC address to ensure that learning bridges correctly determine the LAN segment the virtual router is attached to.
注意：VRRP数据包以虚拟路由器MAC地址作为源MAC地址进行传输，以确保学习网桥正确确定虚拟路由器连接到的LAN网段。
The virtual router MAC address associated with a virtual router is an IEEE 802 MAC Address in the following format:
与虚拟路由器关联的虚拟路由器MAC地址是以下格式的IEEE 802 MAC地址：
IPv4 case: 00-00-5E-00-01-{VRID} (in hex, in Internet-standard bit-order)
IPv4大小写：00-00-5E-00-01-{VRID}（十六进制，互联网标准位顺序）
The first three octets are derived from the IANA's Organizational Unique Identifier (OUI). The next two octets (00-01) indicate the address block assigned to the VRRP for IPv4 protocol. {VRID} is the VRRP Virtual Router Identifier. This mapping provides for up to 255 IPv4 VRRP routers on a network.
前三个八位字节来自IANA的组织唯一标识符（OUI）。接下来的两个八位字节（00-01）表示为IPv4协议分配给VRRP的地址块。{VRID}是VRRP虚拟路由器标识符。此映射在网络上提供多达255个IPv4 VRRP路由器。
IPv6 case: 00-00-5E-00-02-{VRID} (in hex, in Internet-standard bit-order)
IPv6案例：00-00-5E-00-02-{VRID}（十六进制，互联网标准位顺序）
The first three octets are derived from the IANA's OUI. The next two octets (00-02) indicate the address block assigned to the VRRP for IPv6 protocol. {VRID} is the VRRP Virtual Router Identifier. This mapping provides for up to 255 IPv6 VRRP routers on a network.
前三个八位组来自IANA的OUI。接下来的两个八位字节（00-02）表示分配给IPv6协议VRRP的地址块。{VRID}是VRRP虚拟路由器标识符。此映射为网络上最多255个IPv6 VRRP路由器提供支持。
IPv6 routers running VRRP MUST create their Interface Identifiers in the normal manner (e.g., "Transmission of IPv6 Packets over Ethernet Networks" [RFC2464]). They MUST NOT use the virtual router MAC address to create the Modified Extended Unique Identifier (EUI)-64 identifiers.
运行VRRP的IPv6路由器必须以正常方式创建其接口标识符（例如，“通过以太网传输IPv6数据包”[RFC2464]）。他们不得使用虚拟路由器MAC地址创建修改后的扩展唯一标识符（EUI）-64标识符。
This VRRP specification describes how to advertise and resolve the VRRP router's IPv6 link-local address and other associated IPv6 addresses into the virtual router MAC address.
本VRRP规范描述了如何公布VRRP路由器的IPv6链路本地地址和其他相关IPv6地址，并将其解析为虚拟路由器MAC地址。
ICMP redirects may be used normally when VRRP is running between a group of routers. This allows VRRP to be used in environments where the topology is not symmetric.
当VRRP在一组路由器之间运行时，通常可以使用ICMP重定向。这允许VRRP在拓扑结构不对称的环境中使用。
The IPv4 source address of an ICMP redirect should be the address that the end-host used when making its next-hop routing decision. If a VRRP router is acting as Master for virtual router(s) containing addresses it does not own, then it must determine which virtual router the packet was sent to when selecting the redirect source address. One method to deduce the virtual router used is to examine the destination MAC address in the packet that triggered the redirect.
ICMP重定向的IPv4源地址应该是终端主机在做出下一跳路由决策时使用的地址。如果VRRP路由器充当包含其不拥有的地址的虚拟路由器的主路由器，则它必须在选择重定向源地址时确定数据包发送到哪个虚拟路由器。推断使用的虚拟路由器的一种方法是检查触发重定向的数据包中的目标MAC地址。
It may be useful to disable redirects for specific cases where VRRP is being used to load-share traffic between a number of routers in a symmetric topology.
在VRRP用于在对称拓扑中的多个路由器之间加载共享流量的特定情况下，禁用重定向可能很有用。
When a host sends an ARP request for one of the virtual router IPv4 addresses, the Virtual Router Master MUST respond to the ARP request with an ARP response that indicates the virtual MAC address for the virtual router. Note that the source address of the Ethernet frame of this ARP response is the physical MAC address of the physical router. The Virtual Router Master MUST NOT respond with its physical MAC address in the ARP response. This allows the client to always use the same MAC address regardless of the current Master router.
当主机为其中一个虚拟路由器IPv4地址发送ARP请求时，虚拟路由器主机必须使用指示虚拟路由器的虚拟MAC地址的ARP响应来响应ARP请求。请注意，此ARP响应的以太网帧的源地址是物理路由器的物理MAC地址。虚拟路由器主机不得在ARP响应中使用其物理MAC地址进行响应。这允许客户端始终使用相同的MAC地址，而不考虑当前的主路由器。
When a VRRP router restarts or boots, it SHOULD NOT send any ARP messages using its physical MAC address for the IPv4 address it owns; it should only send ARP messages that include virtual MAC addresses.
当VRRP路由器重新启动或引导时，它不应使用其物理MAC地址发送其拥有的IPv4地址的任何ARP消息；它应该只发送包含虚拟MAC地址的ARP消息。
This may entail the following:
这可能涉及以下方面：
o When configuring an interface, Virtual Router Master routers should broadcast a gratuitous ARP request containing the virtual router MAC address for each IPv4 address on that interface.
o 配置接口时，虚拟路由器主路由器应广播一个免费的ARP请求，其中包含该接口上每个IPv4地址的虚拟路由器MAC地址。
o At system boot, when initializing interfaces for VRRP operation, delay gratuitous ARP requests and ARP responses until both the IPv4 address and the virtual router MAC address are configured.
o 在系统启动时，初始化VRRP操作接口时，延迟免费ARP请求和ARP响应，直到配置IPv4地址和虚拟路由器MAC地址。
o When, for example, ssh access to a particular VRRP router is required, an IP address known to belong to that router must be used.
o 例如，当需要ssh访问特定VRRP路由器时，必须使用已知属于该路由器的IP地址。
If Proxy ARP is to be used on a VRRP router, then the VRRP router must advertise the virtual router MAC address in the Proxy ARP message. Doing otherwise could cause hosts to learn the real MAC address of the VRRP router.
如果要在VRRP路由器上使用代理ARP，则VRRP路由器必须在代理ARP消息中公布虚拟路由器MAC地址。否则会导致主机了解VRRP路由器的真实MAC地址。
ICMPv6 redirects may be used normally when VRRP is running between a group of routers [RFC4443]. This allows VRRP to be used in environments where the topology is not symmetric (e.g., the VRRP routers do not connect to the same destinations).
当VRRP在一组路由器之间运行时，通常可以使用ICMPv6重定向[RFC4443]。这允许VRRP在拓扑结构不对称的环境中使用（例如，VRRP路由器不连接到相同的目的地）。
The IPv6 source address of an ICMPv6 redirect should be the address that the end-host used when making its next-hop routing decision. If a VRRP router is acting as Master for virtual router(s) containing addresses it does not own, then it must determine which virtual router the packet was sent to when selecting the redirect source address. A method to deduce the virtual router used is to examine the destination MAC address in the packet that triggered the redirect.
ICMPv6重定向的IPv6源地址应该是终端主机在做出下一跳路由决策时使用的地址。如果VRRP路由器充当包含其不拥有的地址的虚拟路由器的主路由器，则它必须在选择重定向源地址时确定数据包发送到哪个虚拟路由器。推断使用的虚拟路由器的方法是检查触发重定向的数据包中的目标MAC地址。
When a host sends an ND Neighbor Solicitation message for the virtual router IPv6 address, the Virtual Router Master MUST respond to the ND Neighbor Solicitation message with the virtual MAC address for the virtual router. The Virtual Router Master MUST NOT respond with its physical MAC address. This allows the client to always use the same MAC address regardless of the current Master router.
当主机发送虚拟路由器IPv6地址的ND邻居请求消息时，虚拟路由器主机必须使用虚拟路由器的虚拟MAC地址响应ND邻居请求消息。虚拟路由器主机不得使用其物理MAC地址进行响应。这允许客户端始终使用相同的MAC地址，而不考虑当前的主路由器。
When a Virtual Router Master sends an ND Neighbor Solicitation message for a host's IPv6 address, the Virtual Router Master MUST include the virtual MAC address for the virtual router if it sends a source link-layer address option in the neighbor solicitation message. It MUST NOT use its physical MAC address in the source link-layer address option.
当虚拟路由器主机发送主机IPv6地址的ND邻居请求消息时，如果虚拟路由器主机在邻居请求消息中发送源链路层地址选项，则必须包含虚拟路由器的虚拟MAC地址。它不能在源链路层地址选项中使用其物理MAC地址。
When a VRRP router restarts or boots, it SHOULD NOT send any ND messages with its physical MAC address for the IPv6 address it owns; it should only send ND messages that include virtual MAC addresses.
当VRRP路由器重新启动或引导时，它不应发送任何带有其拥有的IPv6地址的物理MAC地址的ND消息；它应该只发送包含虚拟MAC地址的ND消息。
This may entail the following:
这可能涉及以下方面：
o When configuring an interface, Virtual Router Master routers should send an unsolicited ND Neighbor Advertisement message containing the virtual router MAC address for the IPv6 address on that interface.
o 配置接口时，虚拟路由器主路由器应发送未经请求的ND邻居播发消息，其中包含该接口上IPv6地址的虚拟路由器MAC地址。
o At system boot, when initializing interfaces for VRRP operation, all ND Router and Neighbor Advertisements and Solicitation messages must be delayed until both the IPv6 address and the virtual router MAC address are configured.
o 在系统启动时，初始化VRRP操作接口时，所有ND路由器和邻居播发和请求消息必须延迟，直到配置IPv6地址和虚拟路由器MAC地址。
Note that on a restarting Master router where the VRRP protected address is the interface address, (that is, priority 255) duplicate address detection (DAD) may fail, as the Backup router may answer that it owns the address. One solution is to not run DAD in this case.
请注意，在VRRP保护地址为接口地址的重新启动主路由器上，（即优先级255），重复地址检测（DAD）可能会失败，因为备份路由器可能会回答它拥有该地址。一个解决方案是在这种情况下不运行DAD。
When a Backup VRRP router has become Master for a virtual router, it is responsible for sending Router Advertisements for the virtual router as specified in Section 6.4.3. The Backup routers must be configured to send the same Router Advertisement options as the address owner.
当备份VRRP路由器成为虚拟路由器的主路由器时，它负责按照第6.4.3节的规定为虚拟路由器发送路由器广告。备份路由器必须配置为发送与地址所有者相同的路由器播发选项。
Router Advertisement options that advertise special services (e.g., Home Agent Information Option) that are present in the address owner should not be sent by the address owner unless the Backup routers are prepared to assume these services in full and have a complete and synchronized database for this service.
地址所有者不应发送对地址所有者中存在的特殊服务（例如，归属代理信息选项）进行广告的路由器广告选项，除非备份路由器准备完全承担这些服务并为此服务拥有完整和同步的数据库。
If it is not the address owner, a VRRP router SHOULD NOT forward packets addressed to the IPvX address for which it becomes Master. Forwarding these packets would result in unnecessary traffic. Also, in the case of LANs that receive packets they transmit (e.g., Token Ring), this can result in a forwarding loop that is only terminated when the IPvX TTL expires.
如果不是地址所有者，则VRRP路由器不应转发地址为其成为主地址的IPvX地址的数据包。转发这些数据包将导致不必要的通信量。此外，如果LAN接收它们发送的数据包（例如，令牌环），这可能导致转发循环，该循环仅在IPvX TTL过期时终止。
One such mechanism for VRRP routers is to add/delete a reject host route for each adopted IPvX address when transitioning to/from MASTER state.
VRRP路由器的一种机制是在转换到主状态或从主状态转换到主状态时，为每个采用的IPvX地址添加/删除拒绝主机路由。
A priority value of 255 designates a particular router as the "IPvX address owner". Care must be taken not to configure more than one router on the link in this way for a single VRID.
优先级值255指定特定路由器为“IPvX地址所有者”。必须注意，不要以这种方式为单个VRID在链路上配置多个路由器。
Routers with priority 255 will, as soon as they start up, preempt all lower-priority routers. No more than one router on the link is to be configured with priority 255, especially if preemption is set. If no router has this priority, and preemption is disabled, then no preemption will occur.
优先级为255的路由器在启动后将抢占所有低优先级路由器。链路上最多只能配置一个优先级为255的路由器，特别是在设置了抢占的情况下。如果没有路由器具有此优先级，并且已禁用抢占，则不会发生抢占。
When there are multiple Backup routers, their priority values should be uniformly distributed. For example, if one Backup router has the default priority of 100 and another Backup Router is added, a priority of 50 would be a better choice for it than 99 or 100, in order to facilitate faster convergence.
当有多个备份路由器时，它们的优先级值应均匀分布。例如，如果一个备份路由器的默认优先级为100，并且添加了另一个备份路由器，则优先级为50比99或100更好，以便加快收敛速度。
1. VRRPv2 and VRRPv3 interoperation is optional.
1. VRRPv2和VRRPv3互操作是可选的。
2. Mixing VRRPv2 and VRRPv3 should only be done when transitioning from VRRPv2 to VRRPv3. Mixing the two versions should not be considered a permanent solution.
2. 只有在从VRRPv2过渡到VRRPv3时，才能混合VRRPv2和VRRPv3。混合使用这两种版本不应被视为永久解决方案。
As mentioned above, this support is intended for upgrade scenarios and is NOT recommended for permanent deployments.
如上所述，此支持适用于升级场景，不建议用于永久部署。
An implementation MAY implement a configuration flag that tells it to listen for and send both VRRPv2 and VRRPv3 advertisements.
一个实现可以实现一个配置标志，告诉它侦听并发送VRRPv2和VRRPv3广告。
When a virtual router is configured this way and is the Master, it MUST send both types at the configured rate, even if sub-second.
当一个虚拟路由器以这种方式配置并且是主路由器时，它必须以配置的速率发送这两种类型的数据，即使是次秒。
When a virtual router is configured this way and is the Backup, it should time out based on the rate advertised by the Master; in the case of a VRRPv2 Master, this means it must translate the timeout value it receives (in seconds) into centiseconds. Also, a Backup should ignore VRRPv2 advertisements from the current Master if it is also receiving VRRPv3 packets from it. It MAY report when a VRRPv3 Master is *not* sending VRRPv2 packets: that suggests they don't agree on whether they're supporting VRRPv2 routers.
当一个虚拟路由器以这种方式配置并且是备份时，它应该根据主路由器公布的速率超时；对于VRRPv2主机，这意味着它必须将接收到的超时值（以秒为单位）转换为厘米秒。此外，如果备份同时从当前主机接收VRRPv3数据包，则应忽略来自当前主机的VRRPv2播发。当VRRPv3主机*不*发送VRRPv2数据包时，它可能会报告：这表明他们对是否支持VRRPv2路由器不一致。
See also Section 5.2.7, "Maximum Advertisement Interval (Max Adver Int)".
另见第5.2.7节“最大广告间隔（最大广告间隔）”。
The VRRPv2 Master router interacting with a sub-second VRRPv3 Backup router is the most important example of this.
VRRPv2主路由器与次秒级VRRPv3备份路由器交互就是最重要的例子。
A VRRPv2 implementation should not be given a higher priority than a VRRPv2/VRRPv3 implementation it is interacting with if the VRRPv2/ VRRPv3 rate is sub-second.
如果VRRPv2/VRRPv3速率低于每秒，则VRRPv2实现的优先级不应高于与其交互的VRRPv2/VRRPv3实现。
It seems possible that a VRRPv3 Master router sending at centisecond rates could potentially overwhelm a VRRPv2 Backup router with potentially unclear results.
VRRPv3主路由器以每秒的速率发送可能会压倒VRRPv2备份路由器，但结果可能不清楚。
In this upgrade case, a deployment should initially run the VRRPv3 Master routers with lower frequencies (e.g., 100 centiseconds) until the VRRPv2 routers are upgraded. Then, once the deployment has convinced itself that VRRPv3 is working properly, the VRRPv2 support may be unconfigured and then the desired sub-second rates configured.
在这种升级情况下，部署应首先以较低的频率（例如100厘米秒）运行VRRPv3主路由器，直到VRRPv2路由器升级。然后，一旦部署确信VRRPv3工作正常，可能会取消VRRPv2支持的配置，然后配置所需的亚秒速率。
VRRP for IPvX does not currently include any type of authentication. Earlier versions of the VRRP (for IPv4) specification included several types of authentication ranging from none to strong. Operational experience and further analysis determined that these did not provide sufficient security to overcome the vulnerability of misconfigured secrets, causing multiple Masters to be elected. Due to the nature of the VRRP protocol, even if VRRP messages are cryptographically protected, it does not prevent hostile nodes from behaving as if they are a VRRP Master, creating multiple Masters. Authentication of VRRP messages could have prevented a hostile node from causing all properly functioning routers from going into Backup state. However, having multiple Masters can cause as much disruption as no routers, which authentication cannot prevent. Also, even if a hostile node could not disrupt VRRP, it can disrupt ARP and create the same effect as having all routers go into Backup.
IPvX的VRRP目前不包括任何类型的身份验证。VRRP（用于IPv4）规范的早期版本包括从无到强的多种身份验证类型。运行经验和进一步的分析确定，这些并没有提供足够的安全性来克服错误配置的机密的脆弱性，从而导致多个主机被选中。由于VRRP协议的性质，即使VRRP消息受到加密保护，也不能阻止敌对节点像VRRP主节点一样行为，从而创建多个主节点。VRRP消息的身份验证可以防止恶意节点导致所有正常运行的路由器进入备份状态。然而，拥有多个主设备可能会造成与没有路由器一样多的中断，而身份验证无法防止这种情况。此外，即使恶意节点无法中断VRRP，也会中断ARP，并产生与所有路由器进入备份相同的效果。
Some L2 switches provide the capability to filter out, for example, ARP and/or ND messages from end-hosts on a switch-port basis. This mechanism could also filter VRRP messages from switch ports associated with end-hosts and can be considered for deployments with untrusted hosts.
一些L2交换机提供了以交换机端口为基础过滤来自终端主机的ARP和/或ND消息等功能。此机制还可以从与终端主机关联的交换机端口过滤VRRP消息，并且可以考虑使用不受信任的主机进行部署。
It should be noted that these attacks are not worse and are a subset
of the attacks that any node attached to a LAN can do independently
of VRRP. The kind of attacks a malicious node on a LAN can do
include promiscuously receiving packets for any router's MAC address;
sending packets with the router's MAC address as the source MAC
address in the L2 header to tell the L2 switches to send packets
addressed to the router to the malicious node instead of the router;
send redirects to tell the hosts to send their traffic somewhere
else; send unsolicited ND replies; answer ND requests; etc. All of
this can be done independently of implementing VRRP. VRRP does not
add to these vulnerabilities.
It should be noted that these attacks are not worse and are a subset
of the attacks that any node attached to a LAN can do independently
of VRRP. The kind of attacks a malicious node on a LAN can do
include promiscuously receiving packets for any router's MAC address;
sending packets with the router's MAC address as the source MAC
address in the L2 header to tell the L2 switches to send packets
addressed to the router to the malicious node instead of the router;
send redirects to tell the hosts to send their traffic somewhere
else; send unsolicited ND replies; answer ND requests; etc. All of
this can be done independently of implementing VRRP. VRRP does not
add to these vulnerabilities.
Independent of any authentication type, VRRP includes a mechanism (setting TTL = 255, checking on receipt) that protects against VRRP packets being injected from another remote network. This limits most vulnerabilities to local attacks.
独立于任何身份验证类型，VRRP包括一种机制（设置TTL=255，接收时检查），可防止从另一个远程网络注入VRRP数据包。这限制了大多数易受本地攻击的漏洞。
VRRP does not provide any confidentiality. Confidentiality is not necessary for the correct operation of VRRP, and there is no information in the VRRP messages that must be kept secret from other nodes on the LAN.
VRRP不提供任何保密信息。VRRP的正确操作不需要保密，并且VRRP消息中没有必须对LAN上的其他节点保密的信息。
In the context of IPv6 operation, if SEcure Neighbor Discovery (SEND) is deployed, VRRP is compatible with the "trust anchor" and "trust anchor or cga" modes of SEND [RFC3971]. The SEND configuration needs to give the Master and Backup routers the same prefix delegation in the certificates so that Master and Backup routers advertise the same set of subnet prefixes. However, the Master and Backup routers should have their own key pairs to avoid private key sharing.
在IPv6操作的上下文中，如果部署了安全邻居发现（SEND），VRRP与发送的“信任锚”和“信任锚或cga”模式兼容[RFC3971]。发送配置需要在证书中为主路由器和备份路由器提供相同的前缀委派，以便主路由器和备份路由器公布相同的子网前缀集。但是，主路由器和备份路由器应该有自己的密钥对，以避免私钥共享。
The editor would like to thank V. Ullanatt for his review of an early version. This document consists of very little new material (there is some new text in Appendix A) and was created by merging and "xml-izing" [VRRP-IPv6] and [RFC3768], and then adding in the changes discussed recently on the Virtual Router Redundancy Protocol working group's mailing list. R. Hinden is the author and J. Cruz the editor of the former. The contributors for the latter appear below.
编辑要感谢V.Ullanat对早期版本的评论。本文件包含很少的新材料（附录A中有一些新的文本），通过合并和“xml化”[VRRP-IPv6]和[RFC3768]创建，然后添加最近在虚拟路由器冗余协议工作组邮件列表上讨论的更改。R.Hinden是前者的作者，J.Cruz是前者的编辑。后者的贡献者如下所示。
The IPv6 text in this specification is based on [RFC2338]. The authors of RFC2338 are S. Knight, D. Weaver, D. Whipple, R. Hinden, D. Mitzel, P. Hunt, P. Higginson, M. Shand, and A. Lindem.
本规范中的IPv6文本基于[RFC2338]。RFC2338的作者是S.奈特、D.韦弗、D.惠普尔、R.兴登、D.米泽尔、P.亨特、P.希金森、M.尚德和A.林登。
The author of [VRRP-IPv6] would also like to thank Erik Nordmark, Thomas Narten, Steve Deering, Radia Perlman, Danny Mitzel, Mukesh Gupta, Don Provan, Mark Hollinger, John Cruz, and Melissa Johnson for their helpful suggestions.
[VRRP-IPv6]的作者还要感谢Erik Nordmark、Thomas Narten、Steve Deering、Radia Perlman、Danny Mitzel、Mukesh Gupta、Don Provan、Mark Hollinger、John Cruz和Melissa Johnson提出的有益建议。
The IPv4 text in this specification is based on [RFC3768]. The authors of that specification would like to thank Glen Zorn, Michael Lane, Clark Bremer, Hal Peterson, Tony Li, Barbara Denny, Joel Halpern, Steve Bellovin, Thomas Narten, Rob Montgomery, Rob Coltun, Radia Perlman, Russ Housley, Harald Alvestrand, Steve Bellovin, Ned Freed, Ted Hardie, Russ Housley, Bert Wijnen, Bill Fenner, and Alex Zinin for their comments and suggestions.
本规范中的IPv4文本基于[RFC3768]。该规范的作者要感谢格伦·佐恩、迈克尔·莱恩、克拉克·布雷默、哈尔·彼得森、托尼·李、芭芭拉·丹尼、乔尔·哈尔佩恩、史蒂夫·贝洛文、托马斯·纳滕、罗伯·蒙哥马利、罗伯·科尔顿、拉迪亚·帕尔曼、罗斯·霍斯利、哈拉尔·阿尔维斯特兰、史蒂夫·贝洛文、内德·弗里德、泰德·哈迪、罗斯·霍斯利、伯特·维恩、比尔·芬纳、，以及Alex Zinin的评论和建议。
IANA has assigned an IPv6 link-local scope multicast address for VRRP for IPv6. The IPv6 multicast address is as follows:
IANA已为IPv6的VRRP分配了IPv6链路本地作用域多播地址。IPv6多播地址如下所示：
FF02:0:0:0:0:0:0:12
FF02:0:0:0:0:0:0:12
The values assigned address should be entered into Section 5.1.2.2.
分配给地址的值应输入第5.1.2.2节。
The IANA has reserved a block of IANA Ethernet unicast addresses for VRRP for IPv6 in the range
IANA已为IPv6的VRRP保留了范围内的IANA以太网单播地址块
00-00-5E-00-02-00 to 00-00-5E-00-02-FF (in hex)
00-00-5E-00-02-00至00-00-5E-00-02-FF（十六进制）
Similar assignments are documented at:
类似的任务记录在：
http://www.iana.org
http://www.iana.org
[ISO.10038.1993] International Organization for Standardization, "Information technology - Telecommunications and information exchange between systems - Local area networks - Media access control (MAC) bridges", ISO Standard 10038, 1993.
[ISO.10038.1993]国际标准化组织，“信息技术-系统间电信和信息交换-局域网-媒体访问控制（MAC）网桥”，ISO标准100381993。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997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。
[RFC3768] Hinden, R., "Virtual Router Redundancy Protocol (VRRP)", RFC 3768, April 2004.
[RFC3768]Hinden，R.，“虚拟路由器冗余协议（VRRP）”，RFC 3768，2004年4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。
[VRRP-IPv6] Hinden, R. and J. Cruz, "Virtual Router Redundancy Protocol for IPv6", Work in Progress, March 2007.
[VRRP-IPv6]Hinden，R.和J.Cruz，“IPv6虚拟路由器冗余协议”，正在进行的工作，2007年3月。
[IPSTB] Higginson, P. and M. Shand, "Development of Router Clusters to Provide Fast Failover in IP Networks", Digital Technical Journal, Volume 9 Number 3, Winter 1997.
[IPSTB]Higginson，P.和M.Shand，“在IP网络中提供快速故障切换的路由器集群的开发”，数字技术期刊，第9卷第3期，1997年冬季。
[IPX] Novell Incorporated, "IPX Router Specification Version 1.10", October 1992.
[IPX]Novell公司，“IPX路由器规范1.10版”，1992年10月。
[RFC1071] Braden, R., Borman, D., Partridge, C., and W. Plummer, "Computing the Internet checksum", RFC 1071, September 1988.
[RFC1071]Braden，R.，Borman，D.，Partridge，C.，和W.Plummer，“计算互联网校验和”，RFC 10711988年9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。
[RFC1469] Pusateri, T., "IP Multicast over Token-Ring Local Area Networks", RFC 1469, June 1993.
[RFC1469]Pusateri，T.，“令牌环局域网上的IP多播”，RFC 1469，1993年6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。
[RFC2281] Li, T., Cole, B., Morton, P., and D. Li, "Cisco Hot Standby Router Protocol (HSRP)", RFC 2281, March 1998.
[RFC2281]Li，T.，Cole，B.，Morton，P.，和D.Li，“思科热备用路由器协议（HSRP）”，RFC 228112998年3月。
[RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998.
[RFC2328]Moy，J.，“OSPF版本2”，STD 54，RFC 2328，1998年4月。
[RFC2338] Knight, S., Weaver, D., Whipple, D., Hinden, R., Mitzel, D., Hunt, P., Higginson, P., Shand, M., and A. Lindem, "Virtual Router Redundancy Protocol", RFC 2338, April 1998.
[RFC2338]奈特，S.，韦弗，D.，惠普尔，D.，辛登，R.，米特泽尔，D.，亨特，P.，希金森，P.，尚德，M.，和A.林登，“虚拟路由器冗余协议”，RFC 2338，1998年4月。
[RFC2453] Malkin, G., "RIP Version 2", STD 56, RFC 2453, November 1998.
[RFC2453]Malkin，G.，“RIP版本2”，STD 56，RFC 2453，1998年11月。
[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet Networks", RFC 2464, December 1998.
[RFC2464]克劳福德，M.，“通过以太网传输IPv6数据包”，RFC2464，1998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。
[TKARCH] IBM Incorporated, "IBM Token-Ring Network, Architecture Specification, Publication SC30-3374-02, Third Edition", September 1989.
[TKARCH]IBM公司，“IBM令牌环网，体系结构规范，出版物SC30-3374-02，第三版”，1989年9月。
Appendix A. Operation over FDDI, Token Ring, and ATM LANE
附录A.通过FDDI、令牌环和ATM通道的操作
FDDI interfaces remove from the FDDI ring frames that have a source MAC address matching the device's hardware address. Under some conditions, such as router isolations, ring failures, protocol transitions, etc., VRRP may cause there to be more than one Master router. If a Master router installs the virtual router MAC address as the hardware address on a FDDI device, then other Masters' ADVERTISEMENTS will be removed from the ring during the Master convergence, and convergence will fail.
FDDI接口从具有与设备硬件地址匹配的源MAC地址的FDDI环帧中移除。在某些情况下，例如路由器隔离、环故障、协议转换等，VRRP可能会导致存在多个主路由器。如果主路由器将虚拟路由器MAC地址安装为FDDI设备上的硬件地址，则在主汇聚期间，其他主路由器的播发将从环中删除，并且汇聚将失败。
To avoid this, an implementation SHOULD configure the virtual router MAC address by adding a unicast MAC filter in the FDDI device, rather than changing its hardware MAC address. This will prevent a Master router from removing any ADVERTISEMENTS it did not originate.
为了避免这种情况，实现应该通过在FDDI设备中添加单播MAC过滤器来配置虚拟路由器MAC地址，而不是更改其硬件MAC地址。这将阻止主路由器删除其未发起的任何播发。
Token Ring has several characteristics that make running VRRP difficult. These include the following:
令牌环有几个特性使得运行VRRP变得困难。这些措施包括：
o In order to switch to a new Master located on a different bridge Token-Ring segment from the previous Master when using source-route bridges, a mechanism is required to update cached source-route information.
o 在使用源路由网桥时，为了切换到位于与前一个主机不同的网桥令牌环段上的新主机，需要一种机制来更新缓存的源路由信息。
o No general multicast mechanism is supported across old and new Token-Ring adapter implementations. While many newer Token-Ring adapters support group addresses, Token-Ring functional-address support is the only generally available multicast mechanism. Due to the limited number of Token-Ring functional addresses, these may collide with other usage of the same Token-Ring functional addresses.
o 新旧令牌环适配器实现之间不支持通用多播机制。虽然许多较新的令牌环适配器支持组地址，但令牌环功能地址支持是唯一普遍可用的多播机制。由于令牌环功能地址的数量有限，这些地址可能会与相同令牌环功能地址的其他用途发生冲突。
Due to these difficulties, the preferred mode of operation over Token Ring will be to use a Token-Ring functional address for the VRID virtual MAC address. Token-Ring functional addresses have the two high-order bits in the first MAC address octet set to B'1'. They range from 03-00-00-00-00-80 to 03-00-02-00-00-00 (canonical format). However, unlike multicast addresses, there is only one unique functional address per bit position. The functional addresses 03-00-00-10-00-00 through 03-00-02-00-00-00 are reserved by the Token-Ring Architecture [TKARCH] for user-defined applications. However, since there are only 12 user-defined Token-Ring functional addresses, there may be other non-IPvX protocols using the same functional address. Since the Novell IPX [IPX] protocol uses the
由于这些困难，令牌环上的首选操作模式将是为VRID虚拟MAC地址使用令牌环功能地址。令牌环功能地址将第一个MAC地址八位字节中的两个高阶位设置为B'1'。它们的范围从03-00-00-00-00-80到03-00-02-00-00-00（标准格式）。但是，与多播地址不同，每个位位置只有一个唯一的功能地址。令牌环体系结构[TKARCH]为用户定义的应用程序保留了功能地址03-00-00-10-00-00至03-00-02-00-00-00。然而，由于只有12个用户定义的令牌环功能地址，因此可能存在使用相同功能地址的其他非IPvX协议。因为Novell IPX[IPX]协议使用
03-00-00-10-00-00 functional address, operation of VRRP over Token Ring will avoid use of this functional address. In general, Token-Ring VRRP users will be responsible for resolution of other user-defined Token-Ring functional address conflicts.
03-00-00-10-00-00功能地址，通过令牌环操作VRRP将避免使用此功能地址。通常，令牌环VRRP用户将负责解决其他用户定义的令牌环功能地址冲突。
VRIDs are mapped directly to Token-Ring functional addresses. In order to decrease the likelihood of functional-address conflicts, allocation will begin with the largest functional address. Most non-IPvX protocols use the first or first couple user-defined functional addresses, and it is expected that VRRP users will choose VRIDs sequentially, starting with 1.
VRID直接映射到令牌环功能地址。为了减少功能地址冲突的可能性，分配将从最大的功能地址开始。大多数非IPvX协议使用第一个或第一对用户定义的功能地址，预计VRRP用户将从1开始依次选择VRID。
VRID Token-Ring Functional Address
---- -----------------------------
1 03-00-02-00-00-00
2 03-00-04-00-00-00
3 03-00-08-00-00-00
4 03-00-10-00-00-00
5 03-00-20-00-00-00
6 03-00-40-00-00-00
7 03-00-80-00-00-00
8 03-00-00-01-00-00
9 03-00-00-02-00-00
10 03-00-00-04-00-00
11 03-00-00-08-00-00
VRID Token-Ring Functional Address
---- -----------------------------
1 03-00-02-00-00-00
2 03-00-04-00-00-00
3 03-00-08-00-00-00
4 03-00-10-00-00-00
5 03-00-20-00-00-00
6 03-00-40-00-00-00
7 03-00-80-00-00-00
8 03-00-00-01-00-00
9 03-00-00-02-00-00
10 03-00-00-04-00-00
11 03-00-00-08-00-00
Or, more succinctly, octets 3 and 4 of the functional address are equal to (0x4000 >> (VRID - 1)) in non-canonical format.
或者，更简洁地说，功能地址的八位字节3和4在非规范格式中等于（0x4000>>（VRID-1））。
Since a functional address cannot be used as a MAC-level source address, the real MAC address is used as the MAC source address in VRRP advertisements. This is not a problem for bridges, since packets addressed to functional addresses will be sent on the spanning-tree explorer path [ISO.10038.1993].
由于功能地址不能用作MAC级源地址，因此实际MAC地址在VRRP广告中用作MAC源地址。这对于网桥来说不是问题，因为发往功能地址的数据包将在生成树浏览器路径上发送[ISO.10038.1993]。
The functional-address mode of operation MUST be implemented by routers supporting VRRP on Token Ring.
功能地址操作模式必须由在令牌环上支持VRRP的路由器实现。
Additionally, routers MAY support the unicast mode of operation to take advantage of newer Token-Ring adapter implementations that support non-promiscuous reception for multiple unicast MAC addresses and to avoid both the multicast traffic and usage conflicts associated with the use of Token-Ring functional addresses. Unicast mode uses the same mapping of VRIDs to virtual MAC addresses as Ethernet. However, one important difference exists. ND request/reply packets contain the virtual MAC address as the source MAC address. The reason for this is that some Token-Ring driver
此外，路由器可支持单播操作模式，以利用支持多个单播MAC地址的非混杂接收的较新令牌环适配器实现，并避免与令牌环功能地址的使用相关联的多播通信量和使用冲突。单播模式使用与以太网相同的VRID到虚拟MAC地址的映射。然而，存在一个重要的区别。ND请求/应答数据包包含虚拟MAC地址作为源MAC地址。原因是某个令牌环驱动程序
implementations keep a cache of MAC address/source-routing information independent of the ND cache.
实现使MAC地址/源路由信息的缓存独立于ND缓存。
Hence, these implementations have to receive a packet with the virtual MAC address as the source address in order to transmit to that MAC address in a source-route-bridged network.
因此，这些实现必须接收具有虚拟MAC地址作为源地址的分组，以便在源路由桥接网络中传输到该MAC地址。
Unicast mode on Token Ring has one limitation that should be considered. If there are VRID routers on different source-route-bridge segments, and there are host implementations that keep their source-route information in the ND cache and do not listen to gratuitous NDs, these hosts will not update their ND source-route information correctly when a switchover occurs. The only possible solution is to put all routers with the same VRID on the same source-route-bridge segment and use techniques to prevent that bridge segment from being a single point of failure. These techniques are beyond the scope of this document.
令牌环上的单播模式有一个应考虑的限制。如果在不同的源路由网桥段上有VRID路由器，并且有主机实现将其源路由信息保留在ND缓存中，并且不侦听免费的NDs，则在发生切换时，这些主机将无法正确更新其ND源路由信息。唯一可能的解决方案是将具有相同VRID的所有路由器放在同一源路由网桥段上，并使用技术防止网桥段成为单一故障点。这些技术超出了本文档的范围。
For both the multicast and unicast mode of operation, VRRP advertisements sent to 224.0.0.18 should be encapsulated as described in [RFC1469].
对于多播和单播操作模式，发送至224.0.0.18的VRRP广告应按照[RFC1469]中所述进行封装。
Operation of VRRP over ATM LANE on routers with ATM LANE interfaces and/or routers behind proxy LAN Emulation Clients (LECs) are beyond the scope of this document.
在具有ATM通道接口的路由器和/或代理LAN仿真客户端（LEC）后面的路由器上通过ATM通道操作VRRP不在本文件的范围内。
Author's Address
作者地址
Stephen Nadas (editor) Ericsson 900 Chelmsford St., T3 4th Floor Lowell, MA 01851 USA
Stephen Nadas（编辑）爱立信900 Chelmsford St.，T3美国马萨诸塞州洛厄尔市4楼01851
Phone: +1 978 275 7448
EMail: stephen.nadas@ericsson.com
Phone: +1 978 275 7448
EMail: stephen.nadas@ericsson.com