Static and Dynamic routes in the routing table
A routing table contains many types of routes. This tutorial explains static and dynamic routes. Static routes are the routes you manually add to the routing table. Dynamic routes are the routes the router learns from routing protocols.
Routers use routes stored in their routing tables to make forwarding decisions. When a router receives a data packet, it compares the packet's destination network address with the destination network addresses of all available route entries in the routing table.
- If it finds a match, it uses the interface specified in the entry to forward the data packet.
- If it finds multiple matches, it uses the interface specified in the entry matching the maximum IP bits to forward the data packet.
- If it does not find a match, it discards the data packet.
Since a router depends on routing table entries to make forwarding decisions, its routing table must contain entries before it can forward any data packet. A router with an empty routing table discards all packets. There are three ways to add entries to the routing table: automatic, static, and dynamic.
In the automatic method, the router adds routing entries to the routing table based on IP configurations you set on interfaces.
In the static method, you manually add routing entries to the routing table. Routers use the letter S to indicate the static routes in the routing table.
In the dynamic method, you configure a routing protocol, which automatically adds route information to the routing table. The routes a routing protocol adds to the routing table are known as dynamic routes. Routers use the routing protocol's identification letter to indicate dynamically learned routes in the routing table. For example, RIP is a routing protocol. Its identification letter is R. If you configure it on a router and it adds routes to the routing table, the router will use the letter R to indicate all of its routes.
The show ip route command in Privilege Exec lists the routing table entries.
Differences between static and dynamic routes
The following table compares the static and dynamic routes and lists their differences.
| Manual / Static routes | Dynamic routes |
| You manually add these routes to the routing table. | You configure a routing protocol on all network routers. The routing protocol automatically discovers and adds all network routes to the routing table. |
| The default AD value of a static route is 1. | The AD value of a dynamic route depends on its source routing protocol. Different routing protocols have different AD values. |
| Routers do not manage these routes. You have to manage them manually. For example, you must manually remove a route from the routing table if a route goes down. | Routing protocols manage these routes. If a route goes down, the routing protocol automatically removes it from the routing table. |
| It is easy to configure but hard to manage. | It is hard to configure but easy to operate. |
This tutorial is part of the tutorial series "Routing Table Updating Methods and Route Types". Other parts of this series are the following.
Chapter 1 The show ip route command on Routers
Chapter 2 Routing Table Updating Methods
Chapter 3 Directly Connected Routes and Local Routes
Chapter 4 Static and Floating Static Routes Explained
Chapter 5 Static and Dynamic routes in the Routing table
Chapter 6 Default Route in the Routing Table
Chapter 7 Network Routes and Host Routes Explained
Chapter 8 CCNA Exam Practice Question with Answer 1
Conclusion
Static and dynamic are two types of routes in a routing table. A static route is a route that you manually add to the routing table. A dynamic route is a route that a routing protocol discovers in the network and adds to the routing table.
By ComputerNetworkingNotes Updated on 2025-12-09