Problem and Solution of Distance Vector Routing protocols
As we have discussed in what is distance vector routing protocols, this type of protocols have some disadvantage or problem. In this article we will see the Problem and Solution of Distance Vector Routing protocols
Problem No 1: Convergence Time: Convergence Time is very slow.
Convergence time is said the time that router take to know about whole topology. I mean to say, If 10 routers are connected in your topology with one another. Every router is running on distance vector routing protocol for example RIP. Routers send routing information to their neighbor and get update routing information. The time that will be taken to update all networks (whole topology) is known as convergence time.
Distance Vector protocols have periodic timer for 60 sec or 30 sec. It means if you have just 4 networks without redundancy, approx 2-3 minutes can be taken for convergence. Thus, if you have more network, much more time will be taken and will not be much reliable for large network.
Solution of Convergence Time: There would be two solutions for convergence time.
- Periodic Timer Changing: You know that periodic timer of distance vector routing protocol is high. You can change the periodic timer into 5 sec or 10 sec or what you want. It will take less time to converge all networks. But with this you should consider about drawback. Since Distance Vector Routing protocol updates its routing information by broadcast. As you set periodic timer less, much more updating will be broadcasted and network might be engaged. There would be problem with congestion.
- Triggered update: The second solution is implementation of triggered update. If you enable triggered update, Distance vector routing protocol will still update routing information on their periodic timer, but with this whenever any event occurs, it will update information immediately. It looks good but with this solution you can also face another problem. This solution will not efficient with flapping routes.