Comparison of the features of the two types of routing protocols

Many of you know about the dynamic routing protocol. It also includes vector routing protocol and link status routing protocol. I don't know whether you have mastered these two features. Now let's take a closer look.

Dynamic Routing

Dynamic Routing Protocols include distance vector routing protocol and Link State Routing Protocol. These two protocols have their own characteristics and are described as follows.

1. Distance Vector DV) Protocol

Distance vectors refer to the number of hops or vectors used to determine the distance from one device to another. The speed of each hop link is not considered.

The Distance Vector Routing Protocol does not use normal neighbor relationships. Two methods are used to obtain the topology change and route Timeout:

◆ When the router cannot directly receive route updates from the connected router;

◆ When a router receives an update from its neighbor, it notifies the router of a change in its network topology somewhere.

In a small network, there are less than 100 routers, or less route updates and computing environments are required.) The vector routing protocol runs quite well. When a small network is extended to a large network, the convergence speed of the new route is extremely slow for the algorithm to calculate, and the network is in a transitional state during its calculation, loops are likely to occur and cause temporary congestion. Furthermore, when the underlying network link technology is diverse and bandwidth is different, distance vector algorithms turn a blind eye to this.

This feature of the Distance Vector routing protocol not only results in network convergence delay, but also consumes bandwidth. As the route table increases, more CPU resources and memory are consumed.

2. Link Status LS) Routing Protocol

The link status routing protocol does not limit the number of hops. The "graphics theory" algorithm or the Shortest Path priority algorithm is used.

The link status Routing Protocol has a shorter convergence time, supports VLSM Variable Length subnet mask) and CIDR.

The link status routing protocol maintains a normal neighbor relationship between directly connected routes. This allows faster route convergence. The link status Routing Protocol creates a peering relationship by switching the Hello packet or link status information during a session, which accelerates the convergence of the route.

Unlike the distance vector routing protocol, the entire route table is sent during update. The link status routing protocol only broadcasts the updated or changed network topology, which makes the update information smaller and saves bandwidth and CPU usage. In addition, if the network does not change, the update package is usually sent 30 minutes to 2 hours in a specific period of time ).