Network Working Group M. Shand
Request for Comments: 5306 L. Ginsberg
Obsoletes: 3847 Cisco Systems
Category: Standards Track October 2008
Network Working Group M. Shand
Request for Comments: 5306 L. Ginsberg
Obsoletes: 3847 Cisco Systems
Category: Standards Track October 2008
Restart Signaling for IS-IS
IS-IS的重启信令
Status of This Memo
关于下段备忘
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Abstract
摘要
This document describes a mechanism for a restarting router to signal to its neighbors that it is restarting, allowing them to reestablish their adjacencies without cycling through the down state, while still correctly initiating database synchronization.
本文档描述了一种重新启动路由器的机制，该机制用于向其邻居发出重新启动的信号，允许它们在不通过关闭状态循环的情况下重新建立相邻关系，同时仍然正确地启动数据库同步。
This document additionally describes a mechanism for a restarting router to determine when it has achieved Link State Protocol Data Unit (LSP) database synchronization with its neighbors and a mechanism to optimize LSP database synchronization, while minimizing transient routing disruption when a router starts. This document obsoletes RFC 3847.
本文档还描述了一种用于重新启动路由器以确定其何时与邻居实现链路状态协议数据单元（LSP）数据库同步的机制，以及一种用于优化LSP数据库同步的机制，同时最小化路由器启动时的瞬时路由中断。本文件废除了RFC 3847。
Table of Contents
目录
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 4
3. Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Timers . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Restart TLV . . . . . . . . . . . . . . . . . . . . . . . 5
3.2.1. Use of RR and RA Bits . . . . . . . . . . . . . . . . 6
3.2.2. Use of the SA Bit . . . . . . . . . . . . . . . . . . 8
3.3. Adjacency (Re)Acquisition . . . . . . . . . . . . . . . . 8
3.3.1. Adjacency Reacquisition during Restart . . . . . . . . 9
3.3.2. Adjacency Acquisition during Start . . . . . . . . . . 11
3.3.3. Multiple Levels . . . . . . . . . . . . . . . . . . . 12
3.4. Database Synchronization . . . . . . . . . . . . . . . . . 13
3.4.1. LSP Generation and Flooding and SPF Computation . . . 14
3.4.1.1. Restarting . . . . . . . . . . . . . . . . . . . . 14
3.4.1.2. Starting . . . . . . . . . . . . . . . . . . . . . 16
4. State Tables . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1. Running Router . . . . . . . . . . . . . . . . . . . . . . 17
4.2. Restarting Router . . . . . . . . . . . . . . . . . . . . 18
4.3. Starting Router . . . . . . . . . . . . . . . . . . . . . 19
5. Security Considerations . . . . . . . . . . . . . . . . . . . 19
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
7. Manageability Considerations . . . . . . . . . . . . . . . . . 20
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 20
9. Normative References . . . . . . . . . . . . . . . . . . . . . 21
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 4
3. Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Timers . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Restart TLV . . . . . . . . . . . . . . . . . . . . . . . 5
3.2.1. Use of RR and RA Bits . . . . . . . . . . . . . . . . 6
3.2.2. Use of the SA Bit . . . . . . . . . . . . . . . . . . 8
3.3. Adjacency (Re)Acquisition . . . . . . . . . . . . . . . . 8
3.3.1. Adjacency Reacquisition during Restart . . . . . . . . 9
3.3.2. Adjacency Acquisition during Start . . . . . . . . . . 11
3.3.3. Multiple Levels . . . . . . . . . . . . . . . . . . . 12
3.4. Database Synchronization . . . . . . . . . . . . . . . . . 13
3.4.1. LSP Generation and Flooding and SPF Computation . . . 14
3.4.1.1. Restarting . . . . . . . . . . . . . . . . . . . . 14
3.4.1.2. Starting . . . . . . . . . . . . . . . . . . . . . 16
4. State Tables . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1. Running Router . . . . . . . . . . . . . . . . . . . . . . 17
4.2. Restarting Router . . . . . . . . . . . . . . . . . . . . 18
4.3. Starting Router . . . . . . . . . . . . . . . . . . . . . 19
5. Security Considerations . . . . . . . . . . . . . . . . . . . 19
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
7. Manageability Considerations . . . . . . . . . . . . . . . . . 20
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 20
9. Normative References . . . . . . . . . . . . . . . . . . . . . 21
The Intermediate System to Intermediate System (IS-IS) routing protocol [RFC1195] [ISO10589] is a link state intra-domain routing protocol. Normally, when an IS-IS router is restarted, temporary disruption of routing occurs due to events in both the restarting router and the neighbors of the restarting router.
中间系统到中间系统（IS-IS）路由协议[RFC1195][ISO10589]是一种链路状态域内路由协议。通常，当IS-IS路由器重新启动时，由于重新启动的路由器和重新启动的路由器的邻居中的事件，会发生路由的临时中断。
The router that has been restarted computes its own routes before achieving database synchronization with its neighbors. The results of this computation are likely to be non-convergent with the routes computed by other routers in the area/domain.
重新启动的路由器在与其邻居实现数据库同步之前会计算自己的路由。此计算的结果可能与区域/域中其他路由器计算的路由不收敛。
Neighbors of the restarting router detect the restart event and cycle their adjacencies with the restarting router through the down state. The cycling of the adjacency state causes the neighbors to regenerate their LSPs describing the adjacency concerned. This in turn causes a temporary disruption of routes passing through the restarting router.
重新启动路由器的邻居检测到重新启动事件，并在关闭状态下循环与重新启动路由器的邻居。邻接状态的循环导致邻接重新生成其描述相关邻接的LSP。这反过来会导致通过重新启动路由器的路由暂时中断。
In certain scenarios, the temporary disruption of the routes is highly undesirable. This document describes mechanisms to avoid or minimize the disruption due to both of these causes.
在某些情况下，临时中断路线是非常不可取的。本文件描述了避免或最小化这两种原因造成的中断的机制。
When an adjacency is reinitialized as a result of a neighbor restarting, a router does three things:
当邻居重新启动导致邻接重新初始化时，路由器会执行三项操作：
1. It causes its own LSP(s) to be regenerated, thus triggering SPF runs throughout the area (or in the case of Level 2, throughout the domain).
1. 它使其自身的LSP重新生成，从而触发整个区域（或在级别2的情况下，整个域）的SPF运行。
2. It sets SRMflags on its own LSP database on the adjacency concerned.
2. 它在其自己的LSP数据库中的相关邻接上设置SRMflags。
3. In the case of a Point-to-Point link, it transmits a complete set of Complete Sequence Number PDUs (CSNPs), over the adjacency.
3. 在点到点链路的情况下，它通过邻接传输一整套完整的序列号PDU（CSNPs）。
In the case of a restarting router process, the first of these is highly undesirable, but the second is essential in order to ensure synchronization of the LSP database.
在重启路由器进程的情况下，第一个是非常不可取的，但是第二个是必不可少的，以确保LSP数据库的同步。
The third action above minimizes the number of LSPs that must be exchanged and, if made reliable, provides a means of determining when the LSP databases of the neighboring routers have been synchronized. This is desirable whether or not the router is being restarted (so that the overload bit can be cleared in the router's own LSP, for example).
上面的第三个动作最小化了必须交换的LSP的数量，并且，如果变得可靠，则提供了一种确定相邻路由器的LSP数据库何时已经同步的方法。无论路由器是否重新启动，这都是可取的（例如，可以在路由器自己的LSP中清除过载位）。
This document describes a mechanism for a restarting router to signal that it is restarting to its neighbors, and allow them to reestablish their adjacencies without cycling through the down state, while still correctly initiating database synchronization.
本文档描述了一种重新启动路由器的机制，该机制用于向其邻居发出重新启动的信号，并允许它们在不通过关闭状态循环的情况下重新建立相邻关系，同时仍然正确地启动数据库同步。
This document additionally describes a mechanism for a restarting router to determine when it has achieved LSP database synchronization with its neighbors and a mechanism to optimize LSP database synchronization and minimize transient routing disruption when a router starts.
本文档还描述了一种用于重新启动路由器以确定其何时与邻居实现LSP数据库同步的机制，以及一种用于优化LSP数据库同步并在路由器启动时最小化瞬时路由中断的机制。
It is assumed that the three-way handshake [RFC5303] is being used on Point-to-Point circuits.
假设三向握手[RFC5303]用于点对点电路。
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 BCP 14, [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照BCP 14、[RFC2119]中所述进行解释。
If the control and forwarding functions in a router can be maintained independently, it is possible for the forwarding function state to be maintained across a resumption of control function operations. This functionality is assumed when the terms "restart/restarting" are used in this document.
如果路由器中的控制和转发功能可以独立地维护，则可以在控制功能操作的恢复期间维护转发功能状态。当本文档中使用术语“重新启动/重新启动”时，假定此功能。
The terms "start/starting" are used to refer to a router in which the control function has either commenced operations for the first time or has resumed operations, but the forwarding functions have not been maintained in a prior state.
术语“启动/启动”用于指控制功能第一次开始操作或已恢复操作，但转发功能未保持在先前状态的路由器。
The terms "(re)start/(re)starting" are used when the text is applicable to both a "starting" and a "restarting" router.
当文本同时适用于“启动”和“重新启动”路由器时，使用术语“（重新）启动/（重新）启动）”。
Three additional timers, T1, T2, and T3, are required to support the functionality defined in this document.
需要另外三个计时器T1、T2和T3来支持本文档中定义的功能。
An instance of the timer T1 is maintained per interface, and indicates the time after which an unacknowledged (re)start attempt will be repeated. A typical value might be 3 seconds.
每个接口维护一个计时器T1实例，并指示未确认（重新）启动尝试将重复的时间。典型值可能为3秒。
An instance of the timer T2 is maintained for each LSP database (LSPDB) present in the system, i.e., for a Level 1/2 system, there will be an instance of the timer T2 for Level 1 and an instance for Level 2. This is the maximum time that the system will wait for LSPDB synchronization. A typical value might be 60 seconds.
为系统中存在的每个LSP数据库（LSPDB）维护计时器T2的实例，即，对于1/2级系统，将存在用于1级的计时器T2实例和用于2级的计时器T2实例。这是系统等待LSPDB同步的最长时间。典型值可能为60秒。
A single instance of the timer T3 is maintained for the entire system. It indicates the time after which the router will declare that it has failed to achieve database synchronization (by setting the overload bit in its own LSP). This is initialized to 65535 seconds, but is set to the minimum of the remaining times of received IS-IS Hellos (IIHs) containing a restart TLV with the Restart Acknowledgement (RA) set and an indication that the neighbor has an adjacency in the "UP" state to the restarting router.
为整个系统维护定时器T3的单个实例。它表示路由器声明无法实现数据库同步的时间（通过在自己的LSP中设置过载位）。这被初始化为65535秒，但被设置为接收到的is-is Hellos（IIHs）剩余时间的最小值，该is-is Hellos（IIHs）包含设置了重启确认（RA）的重启TLV，并指示邻居与重启路由器的邻接处于“向上”状态。
NOTE: The timer T3 is only used by a restarting router.
注意：计时器T3仅由重新启动的路由器使用。
A new TLV is defined to be included in IIH PDUs. The presence of this TLV indicates that the sender supports the functionality defined in this document and it carries flags that are used to convey information during a (re)start. All IIHs transmitted by a router that supports this capability MUST include this TLV.
新的TLV定义为包含在IIH PDU中。此TLV的存在表明发送方支持本文档中定义的功能，并且它带有用于在（重新）启动期间传递信息的标志。由支持此功能的路由器传输的所有IIH必须包括此TLV。
Type 211
211型
Length: Number of octets in the Value field (1 to (3 + ID Length)) Value
长度：值字段中的八位字节数（1到（3+ID长度））值
No. of octets
+-----------------------+
| Flags | 1
+-----------------------+
| Remaining Time | 2
+-----------------------+
| Restarting Neighbor ID| ID Length
+-----------------------+
No. of octets
+-----------------------+
| Flags | 1
+-----------------------+
| Remaining Time | 2
+-----------------------+
| Restarting Neighbor ID| ID Length
+-----------------------+
Flags (1 octet)
标志（1个八位组）
0 1 2 3 4 5 6 7
+--+--+--+--+--+--+--+--+
| Reserved |SA|RA|RR|
+--+--+--+--+--+--+--+--+
0 1 2 3 4 5 6 7
+--+--+--+--+--+--+--+--+
| Reserved |SA|RA|RR|
+--+--+--+--+--+--+--+--+
RR - Restart Request RA - Restart Acknowledgement SA - Suppress adjacency advertisement
RR-重新启动请求RA-重新启动确认SA-抑制邻接播发
(Note: Remaining fields are required when the RA bit is set.)
（注意：设置RA位时，其余字段为必填字段。）
Remaining Time (2 octets)
剩余时间（2个八位字节）
Remaining holding time (in seconds)
剩余保持时间（秒）
Restarting Neighbor System ID (ID Length octets)
重新启动邻居系统ID（ID长度八位字节）
The System ID of the neighbor to which an RA refers. Note: Implementations based on earlier versions of this document may not include this field in the TLV when the RA is set. In this case, a router that is expecting an RA on a LAN circuit SHOULD assume that the acknowledgement is directed at the local system.
RA引用的邻居的系统ID。注意：在设置RA时，基于本文档早期版本的实现可能不会在TLV中包含此字段。在这种情况下，期望LAN电路上出现RA的路由器应假定确认指向本地系统。
The RR bit is used by a (re)starting router to signal to its neighbors that a (re)start is in progress, that an existing adjacency SHOULD be maintained even under circumstances when the normal operation of the adjacency state machine would require the adjacency to be reinitialized, to request a set of CSNPs, and to request setting of the SRMflags.
RR位由（重新）启动路由器用于向其邻居发出信号，表示（重新）启动正在进行，即使在邻接状态机的正常运行需要重新初始化邻接、请求一组CSNP和请求设置SRMflags的情况下，也应保持现有的邻接。
The RA bit is sent by the neighbor of a (re)starting router to acknowledge the receipt of a restart TLV with the RR bit set.
RA位由（重新）启动路由器的邻居发送，以确认收到设置了RR位的重新启动TLV。
When the neighbor of a (re)starting router receives an IIH with the restart TLV having the RR bit set, if there exists on this interface an adjacency in state "UP" with the same System ID, and in the case of a LAN circuit, with the same source LAN address, then, irrespective of the other contents of the "Intermediate System Neighbors" option (LAN circuits) or the "Point-to-Point Three-Way Adjacency" option (Point-to-Point circuits):
当（重新）启动路由器的邻居接收到具有设置RR位的重启TLV的IIH时，如果此接口上存在状态为“UP”且具有相同系统ID的邻接，并且在LAN电路的情况下，具有相同的源LAN地址，则不管“中间系统邻居”选项的其他内容如何（LAN电路）或“点对点三向邻接”选项（点对点电路）：
a. the state of the adjacency is not changed. If this is the first IIH with the RR bit set that this system has received associated with this adjacency, then the adjacency is marked as being in
a. 邻接的状态不变。如果这是该系统接收到的与该邻接相关的RR位设置的第一个IIH，则该邻接被标记为处于
"Restart mode" and the adjacency holding time is refreshed -- otherwise, the holding time is not refreshed. The "remaining time" transmitted according to (b) below MUST reflect the actual time after which the adjacency will now expire. Receipt of a normal IIH with the RR bit reset will clear the "Restart mode" state. This procedure allows the restarting router to cause the neighbor to maintain the adjacency long enough for restart to successfully complete, while also preventing repetitive restarts from maintaining an adjacency indefinitely. Whether or not an adjacency is marked as being in "Restart mode" has no effect on adjacency state transitions.
“重启模式”和邻接保持时间被刷新——否则，保持时间不被刷新。根据以下（b）传输的“剩余时间”必须反映邻接现在到期的实际时间。接收到带有RR位复位的正常IIH将清除“重启模式”状态。此过程允许重新启动路由器使邻居保持邻接足够长的时间，以便重新启动成功完成，同时防止重复重新启动无限期地保持邻接。邻接是否标记为处于“重新启动模式”对邻接状态转换没有影响。
b. immediately (i.e., without waiting for any currently running timer interval to expire, but with a small random delay of a few tens of milliseconds on LANs to avoid "storms") transmit over the corresponding interface an IIH including the restart TLV with the RR bit clear and the RA bit set, in the case of Point-to-Point adjacencies having updated the "Point-to-Point Three-Way Adjacency" option to reflect any new values received from the (re)starting router. (This allows a restarting router to quickly acquire the correct information to place in its hellos.) The "Remaining Time" MUST be set to the current time (in seconds) before the holding timer on this adjacency is due to expire. If the corresponding interface is a LAN interface, then the Restarting Neighbor System ID SHOULD be set to the System ID of the router from which the IIH with the RR bit set was received. This is required to correctly associate the acknowledgement and holding time in the case where multiple systems on a LAN restart at approximately the same time. This IIH SHOULD be transmitted before any LSPs or SNPs are transmitted as a result of the receipt of the original IIH.
b. 立即（即，不等待任何当前运行的计时器间隔过期，但在LAN上有几十毫秒的小随机延迟以避免“风暴”）通过相应接口传输IIH，包括在RR位清除和RA位设置的情况下重新启动TLV，如果点对点邻接已更新“点对点三向邻接”选项，以反映从（重新）启动路由器接收到的任何新值。（这允许重新启动的路由器快速获取正确的信息以放入其hello。）“剩余时间”必须设置为当前时间（以秒为单位），然后此邻接上的保留计时器将到期。如果对应的接口是LAN接口，则重新启动的邻居系统ID应设置为从中接收具有RR位设置的IIH的路由器的系统ID。如果LAN上的多个系统几乎同时重新启动，则需要正确关联确认和保持时间。由于收到原始IIH，应在传输任何LSP或SNP之前传输该IIH。
c. if the corresponding interface is a Point-to-Point interface, or if the receiving router has the highest LnRouterPriority (with the highest source MAC (Media Access Control) address breaking ties) among those routers to which the receiving router has an adjacency in state "UP" on this interface whose IIHs contain the restart TLV, excluding adjacencies to all routers which are considered in "Restart mode" (note the actual DIS is NOT changed by this process), initiate the transmission over the corresponding interface of a complete set of CSNPs, and set SRMflags on the corresponding interface for all LSPs in the local LSP database.
c. 如果相应的接口是点对点接口，或者如果接收路由器在这些路由器中具有最高的LNROUTERPRIOTY（最高的源MAC（媒体访问控制）地址断开连接），接收路由器在IIH包含重启TLV的接口上与状态“UP”相邻，排除“重启模式”下考虑的所有路由器的邻接（注意，此过程不会改变实际的DIS），通过一整套CSNP的相应接口启动传输，并在本地LSP数据库中所有LSP的相应接口上设置SRMflags。
Otherwise (i.e., if there was no adjacency in the "UP" state to the System ID in question), process the IIH as normal by reinitializing the adjacency and setting the RA bit in the returned IIH.
否则（即，如果在“向上”状态下没有与所讨论的系统ID相邻），则通过重新初始化相邻并在返回的IIH中设置RA位来正常处理IIH。
The SA bit is used by a starting router to request that its neighbor suppress advertisement of the adjacency to the starting router in the neighbor's LSPs.
起始路由器使用SA位请求其邻居在邻居的LSP中抑制与起始路由器相邻的播发。
A router that is starting has no maintained forwarding function state. This may or may not be the first time the router has started. If this is not the first time the router has started, copies of LSPs generated by this router in its previous incarnation may exist in the LSP databases of other routers in the network. These copies are likely to appear "newer" than LSPs initially generated by the starting router due to the reinitialization of LSP fragment sequence numbers by the starting router. This may cause temporary blackholes to occur until the normal operation of the update process causes the starting router to regenerate and flood copies of its own LSPs with higher sequence numbers. The temporary blackholes can be avoided if the starting router's neighbors suppress advertising an adjacency to the starting router until the starting router has been able to propagate newer versions of LSPs generated by previous incarnations.
正在启动的路由器没有维护的转发功能状态。这可能是也可能不是路由器第一次启动。如果这不是路由器第一次启动，则该路由器在其先前版本中生成的LSP副本可能存在于网络中其他路由器的LSP数据库中。由于启动路由器重新初始化LSP片段序列号，这些副本可能比启动路由器最初生成的LSP看起来“更新”。这可能会导致出现临时黑洞，直到更新过程的正常操作导致启动路由器重新生成并用更高的序列号填充其自身LSP的副本。如果起始路由器的邻居禁止发布与起始路由器相邻的广告，直到起始路由器能够传播以前版本生成的较新版本的LSP，则可以避免临时黑洞。
When a router receives an IIH with the restart TLV having the SA bit set, if there exists on this interface an adjacency in state "UP" with the same System ID, and in the case of a LAN circuit, with the same source LAN address, then the router MUST suppress advertisement of the adjacency to the neighbor in its own LSPs. Until an IIH with the SA bit clear has been received, the neighbor advertisement MUST continue to be suppressed. If the adjacency transitions to the "UP" state, the new adjacency MUST NOT be advertised until an IIH with the SA bit clear has been received.
当路由器接收到具有设置SA位的重启TLV的IIH时，如果此接口上存在状态为“UP”且具有相同系统ID的邻接，并且对于具有相同源LAN地址的LAN电路，则路由器必须抑制在其自身LSP中向邻居通告邻接。在接收到SA位为clear的IIH之前，必须继续抑制邻居播发。如果邻接转换为“向上”状态，则在收到SA位为clear的IIH之前，不得公布新邻接。
Note that a router that suppresses advertisement of an adjacency MUST NOT use this adjacency when performing its SPF calculation. In particular, if an implementation follows the example guidelines presented in [ISO10589], Annex C.2.5, Step 0:b) "pre-load TENT with the local adjacency database", the suppressed adjacency MUST NOT be loaded into TENT.
请注意，禁止公布邻接的路由器在执行其SPF计算时不得使用此邻接。特别是，如果实施遵循[ISO10589]，附录C.2.5，步骤0:b）“使用本地邻接数据库预加载帐篷”中给出的示例指南，则禁止将抑制的邻接加载到帐篷中。
Adjacency (re)acquisition is the first step in (re)initialization. Restarting and starting routers will make use of the RR bit in the restart TLV, though each will use it at different stages of the (re)start procedure.
邻接（re）获取是（re）初始化的第一步。重新启动和启动路由器将在重新启动TLV中使用RR位，尽管每个路由器将在（重新）启动过程的不同阶段使用它。
The restarting router explicitly notifies its neighbor that the adjacency is being reacquired, and hence that it SHOULD NOT reinitialize the adjacency. This is achieved by setting the RR bit in the restart TLV. When the neighbor of a restarting router receives an IIH with the restart TLV having the RR bit set, if there exists on this interface an adjacency in state "UP" with the same System ID, and in the case of a LAN circuit, with the same source LAN address, then the procedures described in Section 3.2.1 are followed.
重新启动的路由器显式通知其邻居正在重新获取邻接，因此不应重新初始化邻接。这是通过在重启TLV中设置RR位来实现的。当重新启动路由器的邻居接收到具有设置RR位的重新启动TLV的IIH时，如果该接口上存在状态为“UP”且具有相同系统ID的邻接，并且在LAN电路的情况下，具有相同的源LAN地址，则遵循第3.2.1节中描述的程序。
A router that does not support the restart capability will ignore the restart TLV and reinitialize the adjacency as normal, returning an IIH without the restart TLV.
不支持重启功能的路由器将忽略重启TLV，并按正常方式重新初始化邻接，在不重启TLV的情况下返回IIH。
On restarting, a router initializes the timer T3, starts the timer T2 for each LSPDB, and for each interface (and in the case of a LAN circuit, for each level) starts the timer T1 and transmits an IIH containing the restart TLV with the RR bit set.
重新启动时，路由器初始化计时器T3，为每个LSPDB启动计时器T2，并为每个接口（以及在LAN电路的情况下，为每个级别）启动计时器T1，并发送包含设置了RR位的重新启动TLV的IIH。
On a Point-to-Point circuit, the restarting router SHOULD set the "Adjacency Three-Way State" to "Init", because the receipt of the acknowledging IIH (with RA set) MUST cause the adjacency to enter the "UP" state immediately.
在点对点电路上，重新启动的路由器应将“邻接三向状态”设置为“初始”，因为接收到确认IIH（设置RA）必须使邻接立即进入“向上”状态。
On a LAN circuit, the LAN-ID assigned to the circuit SHOULD be the same as that used prior to the restart. In particular, for any circuits for which the restarting router was previously DIS, the use of a different LAN-ID would necessitate the generation of a new set of pseudonode LSPs, and corresponding changes in all the LSPs referencing them from other routers on the LAN. By preserving the LAN-ID across the restart, this churn can be prevented. To enable a restarting router to learn the LAN-ID used prior to restart, the LAN-ID specified in an IIH with RR set MUST be ignored.
在LAN电路上，分配给电路的LAN-ID应与重启前使用的相同。具体地说，对于重启路由器之前是DIS的任何电路，使用不同的LAN-ID将需要生成一组新的伪节点lsp，并且在从LAN上的其他路由器引用它们的所有lsp中进行相应的更改。通过在重启过程中保留LAN-ID，可以防止这种搅动。要使重新启动的路由器能够在重新启动之前学习使用的LAN-ID，必须忽略在具有RR集的IIH中指定的LAN-ID。
Transmission of "normal" IIHs is inhibited until the conditions described below are met (in order to avoid causing an unnecessary adjacency initialization). Upon expiry of the timer T1, it is restarted and the IIH is retransmitted as above.
“正常”IIH的传输被禁止，直到满足以下所述条件（以避免造成不必要的邻接初始化）。定时器T1到期后，重新启动，并如上所述重新传输IIH。
When a restarting router receives an IIH a local adjacency is established as usual, and if the IIH contains a restart TLV with the RA bit set (and on LAN circuits with a Restart Neighbor System ID that matches that of the local system), the receipt of the acknowledgement over that interface is noted. When the RA bit is set and the state of the remote adjacency is "UP", then the timer T3 is set to the minimum of its current value and the value of the "Remaining Time" field in the received IIH.
当重新启动路由器接收到IIH时，会像往常一样建立本地邻接，如果IIH包含设置了RA位的重新启动TLV（以及具有与本地系统匹配的重新启动邻居系统ID的LAN电路），则会记录通过该接口接收到的确认。当RA位被设置并且远程邻接的状态为“UP”时，定时器T3被设置为其当前值和接收IIH中的“剩余时间”字段的值的最小值。
On a Point-to-Point link, receipt of an IIH not containing the restart TLV is also treated as an acknowledgement, since it indicates that the neighbor is not restart capable. However, since no CSNP is guaranteed to be received over this interface, the timer T1 is cancelled immediately without waiting for a complete set of CSNPs. Synchronization may therefore be deemed complete even though there are some LSPs which are held (only) by this neighbor (see Section 3.4). In this case, we also want to be certain that the neighbor will reinitialize the adjacency in order to guarantee that the SRMflags have been set on its database, thus ensuring eventual LSPDB synchronization. This is guaranteed to happen except in the case where the Adjacency Three-Way State in the received IIH is "UP" and the Neighbor Extended Local Circuit ID matches the extended local circuit ID assigned by the restarting router. In this case, the restarting router MUST force the adjacency to reinitialize by setting the local Adjacency Three-Way State to "DOWN" and sending a normal IIH.
在点对点链路上，接收到不包含重启TLV的IIH也被视为确认，因为它表示邻居无法重启。然而，由于不保证通过该接口接收到CSNP，因此在不等待完整的CSNP集的情况下立即取消计时器T1。因此，即使有一些LSP（仅）由该邻居持有（见第3.4节），也可以认为同步已完成。在这种情况下，我们还希望确保邻居将重新初始化邻接关系，以确保在其数据库上设置了SRMflags，从而确保最终的LSPDB同步。除非接收到的IIH中的邻接三向状态为“向上”，并且相邻扩展本地电路ID与重新启动路由器分配的扩展本地电路ID匹配，否则这是保证发生的。在这种情况下，重新启动的路由器必须通过将本地邻接三向状态设置为“向下”并发送正常IIH来强制邻接重新初始化。
In the case of a LAN interface, receipt of an IIH not containing the restart TLV is unremarkable since synchronization can still occur so long as at least one of the non-restarting neighboring routers on the LAN supports restart. Therefore, T1 continues to run in this case. If none of the neighbors on the LAN are restart capable, T1 will eventually expire after the locally defined number of retries.
在LAN接口的情况下，接收到不包含重启TLV的IIH是不显著的，因为只要LAN上至少一个不重启的相邻路由器支持重启，同步仍然可以发生。因此，T1在这种情况下继续运行。如果LAN上没有任何邻居能够重新启动，T1将在本地定义的重试次数后最终过期。
In the case of a Point-to-Point circuit, the "LocalCircuitID" and "Extended Local Circuit ID" information contained in the IIH can be used immediately to generate an IIH containing the correct three-way handshake information. The presence of "Neighbor Extended Local Circuit ID" information that does not match the value currently in use by the local system is ignored (since the IIH may have been transmitted before the neighbor had received the new value from the restarting router), but the adjacency remains in the initializing state until the correct information is received.
在点对点电路的情况下，可以立即使用IIH中包含的“LocalCircuitID”和“Extended Local circuit ID”信息来生成包含正确的三向握手信息的IIH。忽略与本地系统当前使用的值不匹配的“邻居扩展本地电路ID”信息的存在（因为IIH可能在邻居从重新启动的路由器接收到新值之前已经传输），但是在收到正确的信息之前，邻接仍处于初始化状态。
In the case of a LAN circuit, the source neighbor information (e.g., SNPAAddress) is recorded and used for adjacency establishment and maintenance as normal.
在LAN电路的情况下，源邻居信息（例如，SNPAAddress）被记录并正常用于邻接建立和维护。
When BOTH a complete set of CSNPs (for each active level, in the case of a Point-to-Point circuit) and an acknowledgement have been received over the interface, the timer T1 is cancelled.
当通过接口接收到一整套CSNP（对于每个激活电平，在点对点电路的情况下）和确认时，定时器T1被取消。
Once the timer T1 has been cancelled, subsequent IIHs are transmitted according to the normal algorithms, but including the restart TLV with both RR and RA clear.
一旦定时器T1被取消，随后的IIH将根据正常算法传输，但包括RR和RA清除的重启TLV。
If a LAN contains a mixture of systems, only some of which support the new algorithm, database synchronization is still guaranteed, but the "old" systems will have reinitialized their adjacencies.
如果LAN包含多个系统，其中只有部分系统支持新算法，则仍然可以保证数据库同步，但“旧”系统将重新初始化其相邻系统。
If an interface is active, but does not have any neighboring router reachable over that interface, the timer T1 would never be cancelled, and according to Section 3.4.1.1, the SPF would never be run. Therefore, timer T1 is cancelled after some predetermined number of expirations (which MAY be 1).
如果接口处于活动状态，但没有任何相邻路由器可通过该接口访问，则计时器T1将永远不会被取消，并且根据第3.4.1.1节，SPF将永远不会运行。因此，定时器T1在预定的到期次数（可以是1）之后被取消。
The starting router wants to ensure that in the event that a neighboring router has an adjacency to the starting router in the "UP" state (from a previous incarnation of the starting router), this adjacency is reinitialized. The starting router also wants neighboring routers to suppress advertisement of an adjacency to the starting router until LSP database synchronization is achieved. This is achieved by sending IIHs with the RR bit clear and the SA bit set in the restart TLV. The RR bit remains clear and the SA bit remains set in subsequent transmissions of IIHs until the adjacency has reached the "UP" state and the initial T1 timer interval (see below) has expired.
起始路由器希望确保在相邻路由器与处于“向上”状态的起始路由器相邻时（从起始路由器的前一个版本），该相邻被重新初始化。起始路由器还希望相邻路由器抑制起始路由器邻接的播发，直到实现LSP数据库同步。这是通过在重启TLV中发送带有RR位清除和SA位设置的IIH来实现的。RR位保持清除，SA位在IIHs的后续传输中保持设置，直到邻接达到“向上”状态且初始T1定时器间隔（见下文）到期。
Receipt of an IIH with the RR bit clear will result in the neighboring router utilizing normal operation of the adjacency state machine. This will ensure that any old adjacency on the neighboring router will be reinitialized.
接收到RR位清除的IIH将导致相邻路由器利用邻接状态机的正常操作。这将确保重新初始化相邻路由器上的任何旧邻接。
Upon receipt of an IIH with the SA bit set, the behavior described in Section 3.2.2 is followed.
收到带有SA位集的IIH后，遵循第3.2.2节中描述的行为。
Upon starting, a router starts timer T2 for each LSPDB.
在启动时，路由器为每个LSPDB启动计时器T2。
For each interface (and in the case of a LAN circuit, for each level), when an adjacency reaches the "UP" state, the starting router starts a timer T1 and transmits an IIH containing the restart TLV with the RR bit clear and SA bit set. Upon expiry of the timer T1, it is restarted and the IIH is retransmitted with both RR and SA bits set (only the RR bit has changed state from earlier IIHs).
对于每个接口（对于LAN电路，对于每个级别），当邻接达到“向上”状态时，启动路由器启动计时器T1并传输包含重启TLV的IIH，RR位清除，SA位设置。定时器T1到期后，重新启动定时器T1，并在设置RR和SA位的情况下重新传输IIH（只有RR位的状态与先前的IIH不同）。
Upon receipt of an IIH with the RR bit set (regardless of whether or not the SA bit is set), the behavior described in Section 3.2.1 is followed.
收到设置了RR位的IIH后（无论是否设置了SA位），遵循第3.2.1节中描述的行为。
When an IIH is received by the starting router and the IIH contains a restart TLV with the RA bit set (and on LAN circuits with a Restart Neighbor System ID that matches that of the local system), the receipt of the acknowledgement over that interface is noted.
当启动路由器接收到IIH，且IIH包含设置了RA位的重启TLV（以及在LAN电路上具有与本地系统匹配的重启邻居系统ID），则会记录通过该接口接收到的确认。
On a Point-to-Point link, receipt of an IIH not containing the restart TLV is also treated as an acknowledgement, since it indicates that the neighbor is not restart capable. Since the neighbor will have reinitialized the adjacency, this guarantees that SRMflags have been set on its database, thus ensuring eventual LSPDB synchronization. However, since no CSNP is guaranteed to be received over this interface, the timer T1 is cancelled immediately without waiting for a complete set of CSNPs. Synchronization may therefore be deemed complete even though there are some LSPs that are held (only) by this neighbor (see Section 3.4).
在点对点链路上，接收到不包含重启TLV的IIH也被视为确认，因为它表示邻居无法重启。由于邻居将重新初始化邻接关系，这保证在其数据库上设置了SRMflags，从而确保最终的LSPDB同步。然而，由于不保证通过该接口接收到CSNP，因此在不等待完整的CSNP集的情况下立即取消计时器T1。因此，即使该邻居持有（仅）一些LSP，也可以认为同步已完成（见第3.4节）。
In the case of a LAN interface, receipt of an IIH not containing the restart TLV is unremarkable since synchronization can still occur so long as at least one of the non-restarting neighboring routers on the LAN supports restart. Therefore, T1 continues to run in this case. If none of the neighbors on the LAN are restart capable, T1 will eventually expire after the locally defined number of retries. The usual operation of the update process will ensure that synchronization is eventually achieved.
在LAN接口的情况下，接收到不包含重启TLV的IIH是不显著的，因为只要LAN上至少一个不重启的相邻路由器支持重启，同步仍然可以发生。因此，T1在这种情况下继续运行。如果LAN上没有任何邻居能够重新启动，T1将在本地定义的重试次数后最终过期。更新过程的常规操作将确保最终实现同步。
When BOTH a complete set of CSNPs (for each active level, in the case of a Point-to-Point circuit) and an acknowledgement have been received over the interface, the timer T1 is cancelled. Subsequent IIHs sent by the starting router have the RR and RA bits clear and the SA bit set in the restart TLV.
当通过接口接收到一整套CSNP（对于每个激活电平，在点对点电路的情况下）和确认时，定时器T1被取消。启动路由器发送的后续IIH清除RR和RA位，并在重启TLV中设置SA位。
Timer T1 is cancelled after some predetermined number of expirations (which MAY be 1).
计时器T1在预定的到期次数（可以是1）之后被取消。
When the T2 timer(s) are cancelled or expire, transmission of "normal" IIHs (with RR, RA, and SA bits clear) will begin.
当T2定时器被取消或到期时，“正常”IIH（RR、RA和SA位清除）的传输将开始。
A router that is operating as both a Level 1 and a Level 2 router on a particular interface MUST perform the above operations for each level.
在特定接口上同时作为1级和2级路由器运行的路由器必须对每个级别执行上述操作。
On a LAN interface, it MUST send and receive both Level 1 and Level 2 IIHs and perform the CSNP synchronizations independently for each level.
在LAN接口上，它必须发送和接收级别1和级别2 IIH，并为每个级别独立执行CSNP同步。
On a Point-to-Point interface, only a single IIH (indicating support for both levels) is required, but it MUST perform the CSNP synchronizations independently for each level.
在点对点接口上，只需要一个IIH（表示支持两个级别），但它必须为每个级别独立执行CSNP同步。
When a router is started or restarted, it can expect to receive a complete set of CSNPs over each interface. The arrival of the CSNP(s) is now guaranteed, since an IIH with the RR bit set will be retransmitted until the CSNP(s) are correctly received.
当路由器启动或重新启动时，它可以期望通过每个接口接收完整的CSNP集。现在可以保证CSNP的到达，因为设置了RR位的IIH将被重新传输，直到正确接收到CSNP为止。
The CSNPs describe the set of LSPs that are currently held by each neighbor. Synchronization will be complete when all these LSPs have been received.
CSNP描述每个邻居当前持有的LSP集。收到所有这些LSP后，同步将完成。
When (re)starting, a router starts an instance of timer T2 for each LSPDB as described in Section 3.3.1 or Section 3.3.2. In addition to normal processing of the CSNPs, the set of LSPIDs contained in the first complete set of CSNPs received over each interface is recorded, together with their remaining lifetime. In the case of a LAN interface, a complete set of CSNPs MUST consist of CSNPs received from neighbors that are not restarting. If there are multiple interfaces on the (re)starting router, the recorded set of LSPIDs is the union of those received over each interface. LSPs with a remaining lifetime of zero are NOT so recorded.
当（重新）启动时，路由器为每个LSPDB启动计时器T2实例，如第3.3.1节或第3.3.2节所述。除了CSNPs的正常处理外，还记录通过每个接口接收的第一套完整CSNPs中包含的LSPID集及其剩余寿命。在LAN接口的情况下，一整套CSNP必须由从未重新启动的邻居处接收的CSNP组成。如果（重新）启动的路由器上有多个接口，则记录的LSPID集是通过每个接口接收的接口的并集。剩余寿命为零的LSP不会这样记录。
As LSPs are received (by the normal operation of the update process) over any interface, the corresponding LSPID entry is removed (it is also removed if an LSP arrives before the CSNP containing the reference). When an LSPID has been held in the list for its indicated remaining lifetime, it is removed from the list. When the list of LSPIDs is empty and the timer T1 has been cancelled for all the interfaces that have an adjacency at this level, the timer T2 is cancelled.
当通过任何接口接收到LSP时（通过更新过程的正常操作），相应的LSPID条目将被删除（如果LSP在包含引用的CSNP之前到达，它也将被删除）。当LSPID已在列表中保留其指示的剩余生存期时，它将从列表中删除。当lspid列表为空并且对于在该级别具有邻接的所有接口取消了计时器T1时，计时器T2被取消。
At this point, the local database is guaranteed to contain all the LSP(s) (either the same sequence number or a more recent sequence number) that were present in the neighbors' databases at the time of (re)starting. LSPs that arrived in a neighbor's database after the time of (re)starting may or may not be present, but the normal operation of the update process will guarantee that they will eventually be received. At this point, the local database is deemed to be "synchronized".
此时，本地数据库保证包含（重新）启动时邻居数据库中存在的所有LSP（相同的序列号或较新的序列号）。在（重新）启动后到达邻居数据库的LSP可能存在，也可能不存在，但更新过程的正常操作将保证它们最终会被接收。此时，本地数据库被视为“已同步”。
Since LSPs mentioned in the CSNP(s) with a zero remaining lifetime are not recorded, and those with a short remaining lifetime are deleted from the list when the lifetime expires, cancellation of the timer T2 will not be prevented by waiting for an LSP that will never arrive.
由于CSNP中提及的剩余寿命为零的LSP未被记录，并且剩余寿命较短的LSP在寿命到期时从列表中删除，因此不会通过等待永远不会到达的LSP来阻止计时器T2的取消。
The operation of a router starting, as opposed to restarting, is somewhat different. These two cases are dealt with separately below.
路由器启动与重启的操作有些不同。这两种情况在下文中分别处理。
In order to avoid causing unnecessary routing churn in other routers, it is highly desirable that the router's own LSPs generated by the restarting system are the same as those previously present in the network (assuming no other changes have taken place). It is important therefore not to regenerate and flood the LSPs until all the adjacencies have been re-established and any information required for propagation into the local LSPs is fully available. Ideally, the information is loaded into the LSPs in a deterministic way, such that the same information occurs in the same place in the same LSP (and hence the LSPs are identical to their previous versions). If this can be achieved, the new versions may not even cause SPF to be run in other systems. However, provided the same information is included in the set of LSPs (albeit in a different order, and possibly different LSPs), the result of running the SPF will be the same and will not cause churn to the forwarding tables.
为了避免在其他路由器中造成不必要的路由搅动，非常希望重启系统生成的路由器自身的LSP与网络中先前存在的LSP相同（假设没有发生其他更改）。因此，重要的是，在所有邻接重新建立并且传播到本地LSP所需的任何信息完全可用之前，不要重新生成和淹没LSP。理想情况下，以确定的方式将信息加载到LSP中，以便相同的信息出现在相同LSP中的相同位置（因此LSP与其以前的版本相同）。如果可以实现这一点，新版本甚至可能不会导致SPF在其他系统中运行。但是，如果LSP集合中包含相同的信息（尽管顺序不同，可能不同的LSP），则运行SPF的结果将是相同的，并且不会对转发表造成搅动。
In the case of a restarting router, none of the router's own LSPs are transmitted, nor are the router's own forwarding tables updated while the timer T3 is running.
在重启路由器的情况下，当定时器T3运行时，路由器自身的lsp没有被发送，路由器自身的转发表也没有被更新。
Redistribution of inter-level information MUST be regenerated before this router's LSP is flooded to other nodes. Therefore, the Level-n non-pseudonode LSP(s) MUST NOT be flooded until the other level's T2 timer has expired and its SPF has been run. This ensures that any inter-level information that is to be propagated can be included in the Level-n LSP(s).
在该路由器的LSP被洪水淹没到其他节点之前，必须重新分配层间信息。因此，在另一个级别的T2计时器过期且其SPF运行之前，不得淹没n级非伪节点LSP。这确保要传播的任何级别间信息都可以包含在级别n LSP中。
During this period, if one of the router's own (including pseudonodes) LSPs is received, which the local router does not currently have in its own database, it is NOT purged. Under normal operation, such an LSP would be purged, since the LSP clearly should not be present in the global LSP database. However, in the present circumstances, this would be highly undesirable, because it could cause premature removal of a router's own LSP -- and hence churn in remote routers. Even if the local system has one or more of the
在此期间，如果接收到路由器自己的（包括伪节点）LSP之一，而本地路由器自己的数据库中当前没有该LSP，则不会清除该LSP。在正常操作下，这样的LSP将被清除，因为LSP显然不应该出现在全局LSP数据库中。然而，在目前的情况下，这将是非常不可取的，因为它可能会导致过早地删除路由器自己的LSP，从而在远程路由器中造成混乱。即使本地系统有一个或多个
router's own LSPs (which it has generated, but not yet transmitted), it is still not valid to compare the received LSP against this set, since it may be that as a result of propagation between Level 1 and Level 2 (or vice versa), a further router's own LSP will need to be generated when the LSP databases have synchronized.
路由器自身的LSP（已生成，但尚未发送），将接收到的LSP与该集合进行比较仍然无效，因为可能是由于级别1和级别2之间的传播（反之亦然），当LSP数据库已同步时，需要生成另一个路由器自身的LSP。
During this period, a restarting router SHOULD send CSNPs as it normally would. Information about the router's own LSPs MAY be included, but if it is included it MUST be based on LSPs that have been received, not on versions that have been generated (but not yet transmitted). This restriction is necessary to prevent premature removal of an LSP from the global LSP database.
在此期间，重新启动的路由器应该像通常一样发送CSNPs。可以包括关于路由器自身LSP的信息，但如果包括，则必须基于已接收的LSP，而不是已生成（但尚未传输）的版本。此限制对于防止从全局LSP数据库中过早删除LSP是必要的。
When the timer T2 expires or is cancelled indicating that synchronization for that level is complete, the SPF for that level is run in order to derive any information that is required to be propagated to another level, but the forwarding tables are not yet updated.
当计时器T2过期或被取消指示该级别的同步已完成时，该级别的SPF将运行，以导出需要传播到另一级别的任何信息，但转发表尚未更新。
Once the other level's SPF has run and any inter-level propagation has been resolved, the router's own LSPs can be generated and flooded. Any own LSPs that were previously ignored, but that are not part of the current set of own LSPs (including pseudonodes), MUST then be purged. Note that it is possible that a Designated Router change may have taken place, and consequently the router SHOULD purge those pseudonode LSPs that it previously owned, but that are now no longer part of its set of pseudonode LSPs.
一旦另一层的SPF已经运行并且任何层间传播都已经解决，路由器自己的LSP就可以生成并被淹没。以前被忽略但不属于当前自有LSP集（包括伪节点）的任何自有LSP都必须清除。请注意，可能发生了指定的路由器更改，因此路由器应清除其以前拥有但现在不再是其伪节点LSP集一部分的那些伪节点LSP。
When all the T2 timers have expired or been cancelled, the timer T3 is cancelled and the local forwarding tables are updated.
当所有T2定时器已经过期或被取消时，定时器T3被取消，并且本地转发表被更新。
If the timer T3 expires before all the T2 timers have expired or been cancelled, this indicates that the synchronization process is taking longer than the minimum holding time of the neighbors. The router's own LSP(s) for levels that have not yet completed their first SPF computation are then flooded with the overload bit set to indicate that the router's LSPDB is not yet synchronized (and therefore other routers MUST NOT compute routes through this router). Normal operation of the update process resumes, and the local forwarding tables are updated. In order to prevent the neighbor's adjacencies from expiring, IIHs with the normal interface value for the holding time are transmitted over all interfaces with neither RR nor RA set in the restart TLV. This will cause the neighbors to refresh their adjacencies. The router's own LSP(s) will continue to have the overload bit set until timer T2 has expired or been cancelled.
如果定时器T3在所有T2定时器都已过期或被取消之前过期，则这表示同步处理所花费的时间长于相邻定时器的最小保持时间。对于尚未完成第一次SPF计算的级别，路由器自身的LSP随后被过载位集淹没，以指示路由器的LSPDB尚未同步（因此其他路由器不得通过该路由器计算路由）。更新过程将恢复正常操作，本地转发表也将更新。为了防止邻居的邻接过期，在重启TLV中未设置RR或RA的情况下，在所有接口上传输在保持时间内具有正常接口值的IIH。这将导致邻居刷新其邻接。路由器自己的LSP将继续设置过载位，直到计时器T2过期或被取消。
In the case of a starting router, as soon as each adjacency is established, and before any CSNP exchanges, the router's own zeroth LSP is transmitted with the overload bit set. This prevents other routers from computing routes through the router until it has reliably acquired the complete set of LSPs. The overload bit remains set in subsequent transmissions of the zeroth LSP (such as will occur if a previous copy of the router's own zeroth LSP is still present in the network) while any timer T2 is running.
在启动路由器的情况下，一旦建立了每个邻接，并且在任何CSNP交换之前，路由器自身的第零个LSP将使用过载位集进行传输。这可以防止其他路由器通过路由器计算路由，直到它可靠地获取了完整的LSP集。当任何定时器T2运行时，过载位在第零LSP的后续传输中保持设置（例如，如果路由器自己的第零LSP的先前副本仍然存在于网络中，则将发生）。
When all the T2 timers have been cancelled, the router's own LSP(s) MAY be regenerated with the overload bit clear (assuming the router is not in fact overloaded, and there is no other reason, such as incomplete BGP convergence, to keep the overload bit set) and flooded as normal.
当所有T2定时器被取消时，路由器自身的LSP可以在过载位清除的情况下重新生成（假设路由器实际上没有过载，并且没有其他原因，例如不完全的BGP收敛，以保持过载位设置）并像正常情况一样被淹没。
Other LSPs owned by this router (including pseudonodes) are generated and flooded as normal, irrespective of the timer T2. The SPF is also run as normal and the Routing Information Base (RIB) and Forwarding Information Base (FIB) updated as routes become available.
此路由器拥有的其他LSP（包括伪节点）正常生成和淹没，与计时器T2无关。SPF也正常运行，路由信息库（RIB）和转发信息库（FIB）随着路由可用而更新。
To avoid the possible formation of temporary blackholes, the starting router sets the SA bit in the restart TLV (as described in Section 3.3.2) in all IIHs that it sends.
为了避免可能形成的临时黑洞，启动路由器在其发送的所有IIH中的重启TLV（如第3.3.2节所述）中设置SA位。
When all T2 timers have been cancelled, the starting router MUST transmit IIHs with the SA bit clear.
当所有T2定时器被取消时，启动路由器必须在SA位清除的情况下传输IIHs。
This section presents state tables that summarize the behaviors described in this document. Other behaviors, in particular adjacency state transitions and LSP database update operation, are NOT included in the state tables except where this document modifies the behaviors described in [ISO10589] and [RFC5303].
本节介绍总结本文档中描述的行为的状态表。状态表中不包括其他行为，特别是邻接状态转换和LSP数据库更新操作，除非本文件修改了[ISO10589]和[RFC5303]中描述的行为。
The states named in the columns of the tables below are a mixture of states that are specific to a single adjacency (ADJ suppressed, ADJ Seen RA, ADJ Seen CSNP) and states that are indicative of the state of the protocol instance (Running, Restarting, Starting, SPF Wait).
下表列中指定的状态是特定于单个邻接的状态（ADJ抑制、ADJ Seen RA、ADJ Seen CSNP）和指示协议实例状态（运行、重新启动、启动、SPF等待）的混合状态。
Three state tables are presented from the point of view of a running router, a restarting router, and a starting router.
从运行路由器、重新启动路由器和启动路由器的角度给出了三个状态表。
Event | Running | ADJ suppressed
==============================================================
RX RR | Maintain ADJ State |
| Send RA |
| Set SRM,send CSNP |
| (Note 1) |
| Update Hold Time, |
| set Restart Mode |
| (Note 2) |
-------------+----------------------+-------------------------
RX RR clr | Clr Restart mode |
-------------+----------------------+-------------------------
RX SA | Suppress IS neighbor |
| TLV in LSP(s) |
| Goto ADJ Suppressed |
-------------+----------------------+-------------------------
RX SA clr | |Unsuppress IS neighbor
| | TLV in LSP(s)
| |Goto Running
==============================================================
Event | Running | ADJ suppressed
==============================================================
RX RR | Maintain ADJ State |
| Send RA |
| Set SRM,send CSNP |
| (Note 1) |
| Update Hold Time, |
| set Restart Mode |
| (Note 2) |
-------------+----------------------+-------------------------
RX RR clr | Clr Restart mode |
-------------+----------------------+-------------------------
RX SA | Suppress IS neighbor |
| TLV in LSP(s) |
| Goto ADJ Suppressed |
-------------+----------------------+-------------------------
RX SA clr | |Unsuppress IS neighbor
| | TLV in LSP(s)
| |Goto Running
==============================================================
Note 1: CSNPs are sent by routers in accordance with Section 3.2.1c
注1：根据第3.2.1c节，CSNPs由路由器发送
Note 2: If Restart Mode clear
注2：如果重新启动模式清除
Event | Restarting | ADJ Seen | ADJ Seen | SPF Wait
| | RA | CSNP |
===================================================================
Router | Send IIH/RR | | |
restarts | ADJ Init | | |
| Start T1,T2,T3 | | |
------------+--------------------+-----------+-----------+------------
RX RR | Send RA | | |
------------+--------------------+-----------+-----------+------------
RX RA | Adjust T3 | | Cancel T1 |
| Goto ADJ Seen RA | | Adjust T3 |
----------- +--------------------+-----------+-----------+------------
RX CSNP set| Goto ADJ Seen CSNP | Cancel T1 | |
------------+--------------------+-----------+-----------+------------
RX IIH w/o | Cancel T1 (Point- | | |
Restart TLV| to-point only) | | |
------------+--------------------+-----------+-----------+------------
T1 expires | Send IIH/RR |Send IIH/RR|Send IIH/RR|
| Restart T1 | Restart T1| Restart T1|
------------+--------------------+-----------+-----------+------------
T1 expires | Send IIH/ | Send IIH/ | Send IIH/ |
nth time | normal | normal | normal |
------------+--------------------+-----------+-----------+------------
T2 expires | Trigger SPF | | |
| Goto SPF Wait | | |
------------+--------------------+-----------+-----------+------------
T3 expires | Set overload bit | | |
| Flood local LSPs | | |
| Update fwd plane | | |
------------+--------------------+-----------+-----------+------------
LSP DB Sync| Cancel T2, and T3 | | |
| Trigger SPF | | |
| Goto SPF wait | | |
------------+--------------------+-----------+-----------+------------
All SPF | | | | Clear
done | | | | overload bit
| | | | Update fwd
| | | | plane
| | | | Flood local
| | | | LSPs
| | | | Goto Running
======================================================================
Event | Restarting | ADJ Seen | ADJ Seen | SPF Wait
| | RA | CSNP |
===================================================================
Router | Send IIH/RR | | |
restarts | ADJ Init | | |
| Start T1,T2,T3 | | |
------------+--------------------+-----------+-----------+------------
RX RR | Send RA | | |
------------+--------------------+-----------+-----------+------------
RX RA | Adjust T3 | | Cancel T1 |
| Goto ADJ Seen RA | | Adjust T3 |
----------- +--------------------+-----------+-----------+------------
RX CSNP set| Goto ADJ Seen CSNP | Cancel T1 | |
------------+--------------------+-----------+-----------+------------
RX IIH w/o | Cancel T1 (Point- | | |
Restart TLV| to-point only) | | |
------------+--------------------+-----------+-----------+------------
T1 expires | Send IIH/RR |Send IIH/RR|Send IIH/RR|
| Restart T1 | Restart T1| Restart T1|
------------+--------------------+-----------+-----------+------------
T1 expires | Send IIH/ | Send IIH/ | Send IIH/ |
nth time | normal | normal | normal |
------------+--------------------+-----------+-----------+------------
T2 expires | Trigger SPF | | |
| Goto SPF Wait | | |
------------+--------------------+-----------+-----------+------------
T3 expires | Set overload bit | | |
| Flood local LSPs | | |
| Update fwd plane | | |
------------+--------------------+-----------+-----------+------------
LSP DB Sync| Cancel T2, and T3 | | |
| Trigger SPF | | |
| Goto SPF wait | | |
------------+--------------------+-----------+-----------+------------
All SPF | | | | Clear
done | | | | overload bit
| | | | Update fwd
| | | | plane
| | | | Flood local
| | | | LSPs
| | | | Goto Running
======================================================================
Event | Starting | ADJ Seen RA| ADJ Seen CSNP
=============================================================
Router | Send IIH/SA | |
starts | Start T1,T2 | |
-------------+-------------------+------------+---------------
RX RR | Send RA | |
-------------+-------------------+------------+---------------
RX RA | Goto ADJ Seen RA | | Cancel T1
-------------+-------------------+------------+---------------
RX CSNP Set | Goto ADJ Seen CSNP| Cancel T1 |
-------------+-------------------+------------+---------------
RX IIH w | Cancel T1 | |
no Restart | (Point-to-Point | |
TLV | only) | |
-------------+-------------------+------------+---------------
ADJ UP | Start T1 | |
| Send local LSPs | |
| with overload bit| |
| set | |
-------------+-------------------+------------+---------------
T1 expires | Send IIH/RR |Send IIH/RR | Send IIH/RR
| and SA | and SA | and SA
| Restart T1 |Restart T1 | Restart T1
-------------+-------------------+------------+---------------
T1 expires | Send IIH/SA |Send IIH/SA | Send IIH/SA
nth time | | |
-------------+-------------------+------------+---------------
T2 expires | Clear overload bit| |
| Send IIH normal | |
| Goto Running | |
-------------+-------------------+------------+---------------
LSP DB Sync | Cancel T2 | |
| Clear overload bit| |
| Send IIH normal | |
==============================================================
Event | Starting | ADJ Seen RA| ADJ Seen CSNP
=============================================================
Router | Send IIH/SA | |
starts | Start T1,T2 | |
-------------+-------------------+------------+---------------
RX RR | Send RA | |
-------------+-------------------+------------+---------------
RX RA | Goto ADJ Seen RA | | Cancel T1
-------------+-------------------+------------+---------------
RX CSNP Set | Goto ADJ Seen CSNP| Cancel T1 |
-------------+-------------------+------------+---------------
RX IIH w | Cancel T1 | |
no Restart | (Point-to-Point | |
TLV | only) | |
-------------+-------------------+------------+---------------
ADJ UP | Start T1 | |
| Send local LSPs | |
| with overload bit| |
| set | |
-------------+-------------------+------------+---------------
T1 expires | Send IIH/RR |Send IIH/RR | Send IIH/RR
| and SA | and SA | and SA
| Restart T1 |Restart T1 | Restart T1
-------------+-------------------+------------+---------------
T1 expires | Send IIH/SA |Send IIH/SA | Send IIH/SA
nth time | | |
-------------+-------------------+------------+---------------
T2 expires | Clear overload bit| |
| Send IIH normal | |
| Goto Running | |
-------------+-------------------+------------+---------------
LSP DB Sync | Cancel T2 | |
| Clear overload bit| |
| Send IIH normal | |
==============================================================
Any new security issues raised by the procedures in this document depend upon the ability of an attacker to inject a false but apparently valid IIH, the ease/difficulty of which has not been altered.
本文档中的过程提出的任何新的安全问题取决于攻击者注入虚假但显然有效的IIH的能力，其易用性/难度尚未改变。
If the RR bit is set in a false IIH, neighbors who receive such an IIH will continue to maintain an existing adjacency in the "UP" state and may (re)send a complete set of CSNPs. While the latter action is wasteful, neither action causes any disruption in correct protocol operation.
如果RR位设置为假IIH，则接收此类IIH的邻居将继续在“向上”状态下保持现有邻接，并可能（重新）发送一整套CSNP。虽然后一个操作是浪费，但这两个操作都不会对正确的协议操作造成任何中断。
If the RA bit is set in a false IIH, a (re)starting router that receives such an IIH may falsely believe that there is a neighbor on the corresponding interface that supports the procedures described in this document. In the absence of receipt of a complete set of CSNPs on that interface, this could delay the completion of (re)start procedures by requiring the timer T1 to time out the locally defined maximum number of retries. This behavior is the same as would occur on a LAN where none of the (re)starting router's neighbors support the procedures in this document and is covered in Sections 3.3.1 and 3.3.2.
如果在虚假IIH中设置RA位，则接收此类IIH的（重新）启动路由器可能错误地认为相应接口上存在支持本文档中所述过程的邻居。在该接口上没有收到完整的CSNP集的情况下，这可能会通过要求计时器T1超时本地定义的最大重试次数来延迟（重新）启动程序的完成。此行为与LAN上发生的行为相同，在LAN中，（重新）启动路由器的邻居都不支持本文档中的过程，并在第3.3.1和3.3.2节中介绍。
If an SA bit is set in a false IIH, this could cause suppression of the advertisement of an IS neighbor, which could either continue for an indefinite period or occur intermittently with the result being a possible loss of reachability to some destinations in the network and/or increased frequency of LSP flooding and SPF calculation.
如果在假IIH中设置SA位，则这可能导致抑制is邻居的播发，其可以无限期地持续或间歇性地发生，其结果是可能失去对网络中某些目的地的可达性和/或增加LSP洪泛和SPF计算的频率。
The possibility of IS-IS PDU spoofing can be reduced by the use of authentication as described in [RFC1195] and [ISO10589], and especially the use of cryptographic authentication as described in [RFC5304].
IS-IS PDU欺骗的可能性可以通过使用[RFC1195]和[ISO10589]中所述的身份验证，特别是使用[RFC5304]中所述的加密身份验证来降低。
This document defines the following IS-IS TLV that is listed in the IS-IS TLV codepoint registry:
本文档定义了IS-IS TLV代码点注册表中列出的以下IS-IS TLV：
Type Description IIH LSP SNP
---- ----------------------------------- --- --- ---
211 Restart TLV y n n
Type Description IIH LSP SNP
---- ----------------------------------- --- --- ---
211 Restart TLV y n n
These extensions that have been designed, developed, and deployed for many years do not have any new impact on management and operation of the IS-IS protocol via this standardization process.
经过多年的设计、开发和部署，这些扩展并没有通过此标准化过程对IS-IS协议的管理和操作产生任何新的影响。
The authors would like to acknowledge contributions made by Jeff Parker, Radia Perlman, Mark Schaefer, Naiming Shen, Nischal Sheth, Russ White, and Rena Yang.
作者要感谢Jeff Parker、Radia Perlman、Mark Schaefer、沈乃明、Nischal Sheth、Russ White和Rena Yang所做的贡献。
[ISO10589] ISO, "Intermediate System to Intermediate System intra-domain routeing information exchange protocol for use in conjunction with the protocol for providing the connectionless-mode network service (ISO 8473)", International Standard 10589:2002, Second Edition, 2002.
[ISO10589]ISO，“与提供无连接模式网络服务协议（ISO 8473）一起使用的中间系统到中间系统域内路由信息交换协议”，国际标准10589:2002，第二版，2002年。
[RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and dual environments", RFC 1195, December 1990.
[RFC1195]Callon，R.，“OSI IS-IS在TCP/IP和双环境中的路由使用”，RFC 11951990年12月。
[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。
[RFC5303] Katz, D., Saluja, R., and D. Eastlake 3rd, "Three-Way Handshake for IS-IS Point-to-Point Adjacencies", RFC 5303, October 2008.
[RFC5303]Katz，D.，Saluja，R.，和D.Eastlake 3rd，“IS-IS点对点邻接的三方握手”，RFC 5303，2008年10月。
[RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic Authentication", RFC 5304, October 2008.
[RFC5304]Li，T.和R.Atkinson，“IS-IS加密认证”，RFC 5304，2008年10月。
Authors' Addresses
作者地址
Mike Shand Cisco Systems 250, Longwater Avenue. Reading, Berks RG2 6GB UK
Mike Shand Cisco Systems 250，Longwater大道。雷丁，伯克斯RG2 6GB英国
Phone: +44 208 824 8690
EMail: mshand@cisco.com
Phone: +44 208 824 8690
EMail: mshand@cisco.com
Les Ginsberg Cisco Systems 510 McCarthy Blvd Milpitas, CA 95035 USA
莱斯金斯伯格思科系统公司美国加利福尼亚州米尔皮塔斯麦卡锡大道510号，邮编95035
EMail: ginsberg@cisco.com
EMail: ginsberg@cisco.com
Full Copyright Statement
完整版权声明
Copyright (C) The IETF Trust (2008).
版权所有（C）IETF信托基金（2008年）。
This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights.
本文件受BCP 78中包含的权利、许可和限制的约束，除其中规定外，作者保留其所有权利。
This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
本文件及其包含的信息以“原样”为基础提供，贡献者、他/她所代表或赞助的组织（如有）、互联网协会、IETF信托基金和互联网工程任务组不承担任何明示或暗示的担保，包括但不限于任何保证，即使用本文中的信息不会侵犯任何权利，或对适销性或特定用途适用性的任何默示保证。
Intellectual Property
知识产权
The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79.
IETF对可能声称与本文件所述技术的实施或使用有关的任何知识产权或其他权利的有效性或范围，或此类权利下的任何许可可能或可能不可用的程度，不采取任何立场；它也不表示它已作出任何独立努力来确定任何此类权利。有关RFC文件中权利的程序信息，请参见BCP 78和BCP 79。
Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr.
向IETF秘书处披露的知识产权副本和任何许可证保证，或本规范实施者或用户试图获得使用此类专有权利的一般许可证或许可的结果，可从IETF在线知识产权存储库获取，网址为http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org.
IETF邀请任何相关方提请其注意任何版权、专利或专利申请，或其他可能涵盖实施本标准所需技术的专有权利。请将信息发送至IETF的IETF-ipr@ietf.org.