Overview of Vector Routing Protocol

When using the routing protocol, we often encounter problems related to the vector routing protocol. Many friends do not know much about this, here we will analyze the content about it. When two different routing protocols need to exchange route information, multiple routing protocols are required. Of course, route redistribution can also exchange route information ｡

Multi-route protocol is not required in the following cases:

From the old version of the Internal Gateway Protocol (Interior Gateway Protocol, I G P) upgrade IGP to the new version. You want to use another routing protocol, but you must retain the original protocol, to avoid interference from other routers without strict filtering and supervision functions. You are in an environment composed of routers from multiple manufacturers ｡

What is distance vector protocol?

Distance Vector routing protocols are designed for small network environments. In large network environments, such protocols generate large traffic when learning routes and maintaining routes, occupying excessive bandwidth ｡

If the route selection table update is not received from the adjacent site within 90 seconds, it is considered that the adjacent site is inaccessible. every 30 seconds, the Distance Vector Routing Protocol sends the entire route selection table to the adjacent site to update the route selection table of the adjacent site ｡

In this way, it can collect a list of networks from other sites (directly connected or otherwise connected) for routing selection. Distance vector protocol uses the number of hops as the metric value, to calculate the number of routers that need to pass through the destination. The algorithm determines the shortest path, that is, the line that can reach the destination as long as it passes through the smallest hop count. The maximum number of hops allowed is usually set to 15. terminals that must pass through more than 5 vrouters are considered inaccessible. Distance vector protocols include ip rip, ipx rip, Apple Talk rt mp, and IGRP.

What is the link status routing protocol?

The link status routing protocol is more suitable for large networks, but due to its complexity, this allows the router to require more CPU resources. It can detect broken links or newly connected routers in a shorter period of time, the convergence time of the Protocol is shorter than that of the vector routing protocol. Generally, the he l lo packet of the neighboring station is not received within 10 seconds, it considers that the neighboring station is no longer reachable. A connection status router sends an update packet to its neighboring station, notify all the links it knows. It determines that the measurement value of the optimal path is a numerical cost, the value of this price is generally determined by the bandwidth of the link. The link with the minimum price is considered optimal ｡

In the Shortest Path priority algorithm, the maximum possible cost is almost unlimited. If the network does not change, A router can refresh the route selection table that has not been updated cyclically (the length of the cycle can be from 3 0 minutes to 2 hours). There are several connection status routing protocols: ip ospf, ipx nlsp, and IS-IS. can a vro use the distance vector protocol and the link status routing protocol? Yes. Each interface can be configured to use different routing protocols. However, they must be able to exchange routing information by allocating routes ｡

What is an access table?

The access table is a series of control data packet Input and Output rules added by the manager in the vro. It is not generated by the vro itself. The Access Table allows or disables data packets from accessing or outputting to the destination. table items are executed sequentially, when a data packet arrives, first check whether it is restricted by the first table item. If not, execute it in sequence. If it matches the first table item, whether it is allowed or disabled, you no longer have to perform the following table item check. Each Protocol of each interface can only have one access table. What types of access tables are supported? The number of an access table can be determined ｡