Distance Vector Routing Protocol

Among the networks, the most important thing is the number of routers and switches. This is what every network administrator must master. Today, we will introduce the Distance Vector Routing Protocol in the routing protocol, including how to determine the adjacent router to your network ｡

Why is it important to determine the adjacent router?

Determining the adjacent router in a small network is not a major problem, because when a router fails, other routers can converge within an acceptable period of time. But in a large network, the latency of a faulty router may be high. Knowing that the adjacent router can accelerate convergence, because the router can know the faulty router more quickly, because the interval of hello messages is shorter than the interval of router exchange information ｡

When a router using the distance vector routing protocol does not send route update information to the adjacent router, it can be found that the adjacent router is no longer reachable. This time is generally 10 ~ 90 seconds. If the router using the link status routing protocol does not receive the hello message, it can be found that the adjacent router is inaccessible. The interval is generally 10 seconds ｡

How can I find the adjacent router through distance vector routing protocol and link status routing protocol?

A Router using the Distance Vector Routing Protocol needs to create a route table (including the network directly connected to it ), at the same time, it will send the route table to the router directly connected to it. The adjacent router combines the received route table into its own route table, at the same time, it also needs to send its route table to its adjacent router ｡

A connection status table is created for the router that uses the link status routing protocol, including the list of destination sites of the entire network. In the update report, each router sends its entire list. When the adjacent router receives this update message, it copies the content, at the same time, the information is sent to its neighbor station. When forwarding the content of the route table, there is no need to re-calculate it ｡

Note that the hello message is broadcast by the routers of IGRP and VPN to discover the adjacent station. At the same time, the route update information is exchanged like OSPF, it includes the address of the neighboring station, the number of messages waiting to be sent in the queue, and the average time required to receive or send messages to the neighboring station, and the time when no message is received from the neighboring station before the link is confirmed to be disconnected ｡