Static Routes and Static Routing Explained

This tutorial explains what static routing and static routes are. Learn the advantages and disadvantages of static routing and where to use static routing.

Routers connect different networks. They receive data packets from a network, read the destination address of each data packet, and forward the data packet to the destination network. To forward data packets, they learn all routes of the network and store them into the routing table.

The routing table stores each route in a separate line as a separate entry. A routing table entry contains the network address of the destination network and either the name of the local interface connected to the destination network or the IP address of the remote router that knows how to reach the destination network.

There are three methods to add entries to the routing table. These methods are default or automatic, manual or static, and dynamic. In the default method, the router automatically adds routing entries for its interfaces.

We have already discussed the default method of routing in the following tutorial.

Connected Routes and Local Routes Explained

We will discuss, the dynamic method in the next tutorial. In this tutorial, we will discuss the static or the manual method of routing.

Static or manual routing

The static or manual method to add entries to the routing table is known as static or manual routing. In static or manual routing, the administrator manually adds entries to the routing table. The administrator creates a virtual map of all routes and manually adds them to each router’s routing table.

Routes that are manually added by an administrator to the routing table are known as static routes. In other words, a static route is a route that you manually add to the router’s routing table.

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Advantages of static routing

Static routing allows the administrator to save money. In static routing, the router does not use CPU and RAM to learn the routes and calculate the best route to each destination. Since static routing does not put overhead on the router's CPU and RAM, the administrator can use a cheaper router.

In static routing, routers do not exchange routing information. Since routers do not exchange routing information, they save the network bandwidth. If in a network, routers are connected through a paid WAN link, static routing can reduce the bill amount that the network pays for WAN connectivity.

Static routing is the safest method of routing. The administrator manually adds routes for authorized networks. Since the administrator manually decides which network can reach which network, a network can only access the authorized network.

Disadvantages of static routing

In static routing, since the administrator adds and manages all routes, the administrator must have in-depth knowledge of the internetwork.

To add all routes correctly, the administrator has to learn how each router is connected to the network.

The process of adding each route on each router is tedious.

If the administrator changes the location of a router in the network, the administrator has to update routing information on all routers manually.

If a link goes up or down, the administrator has to manually update this information on all routers. On a flipping link, this will cause a huge problem.

If you have a backup route, the router doesn't automatically switch to the backup route if the main route fails. The administrator must have to reconfigure the router to use the backup route.

Usages of static routing

Static routing is a good option when the network size is small. In a small network, static routing offers many benefits at the cost of little manual work. You can use static routing to reduce the overhead from routers or save bandwidth on paid WAN connections.

Static routing is not a good choice when the network size is big. In a big network, where you have hundreds of routes, static routing is not scalable, since you would have to configure each route and any redundant paths for that route on each router.

This tutorial is the first part of the tutorial "Static Routing Configuration, Commands, and Concepts Explained". The other parts of this tutorial are the following.

Types of Static Routes Explained
IP Route command Explained with Examples
Static Routing Configuration Guide with Examples

That's all for the first part of the tutorial. In this part, we discussed what static routing and static routes are and learned the advantages and disadvantages of static routing. In the next part of this tutorial, we will learn the types of static routes.

ComputerNetworkingNotes CCNA Study Guide Static Routes and Static Routing Explained