Static Routes and Dynamic Routes

Differences Between Static Routes and Dynamic Routes

Routing protocols are the rules used by routers to discover routes, generate and maintain routing tables, and guide packet forwarding. Routes are classified into the following types based on the origin:

• Direct route: is discovered by link layer protocols.
• Static route: is manually configured by network administrators.
• Dynamic route: is discovered by dynamic routing protocols.

Static routes are easy to configure, have low requirements on the system, and apply to simple, stable, and small networks. The disadvantage of static routes is that they cannot automatically adapt to network topology changes. Therefore, static routes require subsequent maintenance.

Dynamic routing protocols have their routing algorithms. Therefore, dynamic routes can automatically adapt to network topology changes and apply to the networks on which Layer 3 devices are deployed. The configurations of dynamic routes are complex. Dynamic routes have higher requirements on the system than static ones and consume network resources and system resources.

Classification of Dynamic Routing Protocols

Based on the application range, dynamic routing protocols are classified into the following types:

• Interior Gateway Protocol (IGP): runs inside an AS, such as RIP, OSPF, and IS-IS.
• Exterior Gateway Protocol (EGP): runs between different ASs, such as BGP.

Based on the type of algorithm they use, dynamic routing protocols are classified into the following types:

• Distance-vector routing protocol: includes RIP and BGP. BGP is also called path-vector protocol.
• Link-state routing protocol: includes OSPF and IS-IS.

The preceding algorithms differ mainly in route discovery and calculation methods.