Computer Science – 2.1 Networks including the internet | e-Consult

Dynamic routing is a process where routers automatically learn and adapt to changes in the network topology. Unlike static routing, where routes are manually configured, dynamic routing protocols allow routers to exchange information about network connectivity and build their routing tables automatically. This makes dynamic routing more flexible and resilient to network changes.

Distance Vector Routing Protocols:

Distance vector protocols (e.g., RIP - Routing Information Protocol) operate by exchanging routing tables with neighboring routers. Each router advertises its routing table to its direct neighbors, which includes the distance (e.g., hop count) to each destination network. Routers then use this information to determine the best path to each destination.

Key Characteristics:

• Routers only know about networks directly connected to them.
• Routing tables are incomplete, as they only contain information about the closest networks.
• Prone to routing loops (e.g., count-to-infinity problem) if not implemented carefully.
• Simple to implement.

Link-State Routing Protocols:

Link-state protocols (e.g., OSPF - Open Shortest Path First, IS-IS) operate by building a complete map of the network topology. Each router floods the network with link-state advertisements (LSAs), which contain information about the links directly connected to that router and the cost (e.g., bandwidth, delay) associated with those links.

Key Characteristics:

• Routers have a complete view of the network topology.
• Routing tables are complete and accurate.
• More complex to implement than distance vector protocols.
• Less prone to routing loops.
• More efficient for large networks.

Comparison Table: