Comprehensive Understanding of route selection protocols

In the network, we usually use routers to allocate IP addresses. In the network protocol, the protocol that regulates the routing status is the routing selection protocol. Now let's take a look at the specific content of the routing protocol. First, let's take a look at its basic concepts and definitions.

The routing selection protocol enables the router to dynamically broadcast and acquire paths and determine which paths are available for selection, and which one is the best path to transmit data to the destination address. The routing protocol updates the network status of the layer-3 and keeps the route table in the layer-3 Switch/router. Common layer-3 protocols, such as IP, IPX, and AppleTalk, are called routing forwarding protocols that can transmit data over the network.

There are two routing protocols: distance vector routing protocol and link status routing protocol. In essence, the distance vector routing protocol determines whether the path is optimal in terms of distance, and the link status routing protocol can consider various connection variables in a more complex way, such as bandwidth, latency, reliability, and load.

The distance vector routing protocol determines whether the path is optimal based on the distance. The distance can be the number of transit site routes or hosts, or a set of calculated metrics that can replace the distance. Currently, IP distance vector routing protocols are still in use: RIV v1 and v2) and IGRP are developed by Cisco ).

Link Status routing is a concept used to find the path for computer communication in a group switching network. The routing of link status is to let the vro in the network tell all other vrouters in the network which is adjacent to it. All routers do not publish the entire route table. They only distribute the route tables related to the adjacent routers.

Some link status routing protocols are OSPF, IS-IS, and OSPF. Novell's NLSPNetWare Link State Protocol) is also a Link State routing Protocol, but it only supports IPX Protocol. This routing protocol requires that at least one part of the Network Map be stored in each vro. After the network connection status changes, or vice versa, a flag called the link status broadcast LSA will be transmitted throughout the network. Each vro receives a sign that the connection status changes, and then recalculates the path.

In a small network, the distance vector routing protocol is relatively simple and effective, and even if you need to manage it, the workload is relatively small. However, their algorithm design is not concise and the convergence performance is not high, which makes it necessary for us to select a protocol for Link State routing that is more complex for large-scale network development and more concise algorithms.

The link status routing protocol has higher flexibility and perfection than the distance vector routing protocol. They integrate many factors such as bandwidth, latency, reliability, and load, thus reducing the amount of information distributed in the network, it can also make a better decision on the path selection, instead of using the distance or number of transit sites as the unique basis of the Distance Vector routing selection protocol.

IP route table)