动态路由协议_动态路由协议的类别

动态路由协议

Dynamic routing protocols have been divided into 2 categories i.e Distance vector protocols and Link state protocols. Both of these protocols are being explained in detail in this tutorial.

动态路由协议分为距离矢量协议和链路状态协议两大类 。本教程将详细说明这两种协议。

1)距离矢量路由协议 (1) Distance Vector Routing Protocols)

RIP and IGRP are the distance vector routing protocols. All the distance vector routing protocols have some features which are being given below.

RIP和IGRP是距离矢量路由协议。所有距离矢量路由协议都具有以下功能。

The periodic updates of the entire routing table are sent to all neighboring routers.
整个路由表的定期更新将发送到所有相邻路由器。
Convergence is very slow in distance vector protocols and these are susceptible to protocols loops.
距离矢量协议的收敛非常慢，并且容易受到协议循环的影响。
The distance is used to calculate the metric of the routing.
距离用于计算路由度量。
Bellman-Ford algorithm is used to find the shortest path.
Bellman-Ford算法用于查找最短路径。

Distance vector routing protocols send updates about all connected neighbors directly connected networks. This update is sent regularly. It is sent to RIP every 30 seconds and in IGRP, this update is sent every 90 seconds. With these updates, neighbors can add routes to their routing tables. After this, all the neighbors forward their entire routing table, sharing it with all the neighbors.

距离矢量路由协议发送有关所有已连接邻居的直连网络的更新。此更新会定期发送。它每30秒发送到RIP，在IGRP中，此更新每90秒发送一次。通过这些更新，邻居可以将路由添加到其路由表中。此后，所有邻居都转发其整个路由表，并与所有邻居共享。

There are many disadvantages to this kind of process. Routing information goes from one neighbor to pass periodic updates of another, so convergence is very slow. Together, all the neighbors depend on each other, so the chances of looping are also very high.

这种过程有很多缺点。路由信息从一个邻居传到另一个邻居的定期更新，因此收敛非常慢。在一起，所有邻居都相互依赖，因此循环的机会也很高。

Distance vector protocols use distance to calculate metric. RIP is calculated by metric hop counts. In IGRP the metric is calculated with bandwidth and delay.

距离矢量协议使用距离来计算度量。 RIP通过跃点计数来计算。在IGRP中，度量标准是根据带宽和延迟来计算的。

2)链路状态路由协议 (2) Link State Routing Protocols)

Link state protocols were developed to overcome looping and convergence problems in the distance vector protocols. Link state routing protocols build 3 kinds of routing tables. These are being given below.

开发了链路状态协议以克服距离矢量协议中的循环和收敛问题。链路状态路由协议建立3种路由表。这些在下面给出。

Neighbor table
邻居表

This table contains a list of all the neighbors, and also, which of the neighbors is connected to which interface. Neighbor table is created by sending hello packets.
该表包含所有邻居的列表，以及哪个邻居连接到哪个接口。邻居表是通过发送hello数据包创建的。
Topology table
拓扑表

This is also called link state table. In this, all links of one area are stored in the map. Also, every link's status is also stored.
这也称为链接状态表。这样，一个区域的所有链接都存储在地图中。同样，每个链接的状态也会被存储。
Shortest path table
最短路径表

The best routes are stored for every destination in this table. The link states sending updates about the status of routers directly connected networks in routing protocols. All routers store this information in the topology table. The number of routers within an area is their topology table.
最佳路线存储在此表中的每个目的地。链接状态发送有关路由协议中与路由器直接连接的网络的状态有关的更新。所有路由器都将此信息存储在拓扑表中。一个区域内的路由器数量是其拓扑表。

If any change occurs in a link, only related updates to this link are sent to all routers and all routers adjust their topology table accordingly. The only link that has changed has been updated, due to this, the bandwidth also does not have much effect. But due to the management of 3 tables, the CPU is highly utilized. The shortest path is calculated by the Dijkstra formula in the link state protocols.

如果链接发生任何更改，则仅对此链接的相关更新会发送到所有路由器，并且所有路由器都会相应地调整其拓扑表。唯一已更改的链接已更新，因此，带宽也没有太大影响。但是由于管理3个表，因此CPU利用率很高。最短路径由链路状态协议中的Dijkstra公式计算得出。