Routers operate on the Network Layer, which is the third layer (Layer 3) of the OSI model. This layer is also known as the internet layer. Routers are essential for moving data packets between different networks by examining the network address in each packet and determining the best path to forward it. They don't work at the data link layer (Layer 2), which handles MAC addresses, nor do they operate at higher layers like the transport or application layers, which manage data flow and applications, respectively.
- Key Role: Routers determine the best path for data packets based on network addresses, enabling communication across different networks. This is fundamental to how the internet functions.
- OSI Model Layer: The Network Layer's primary function is to handle addressing and routing of packets. Routers directly implement this function.
- Layer 3 Device: Routers are specifically classified as Layer 3 devices due to their network layer operations. While they may have some Layer 2 capabilities (like switching), their core function is routing at Layer 3.
For example, if you send a packet from your home computer to a server in a different country, routers along the path will use the destination network address in the packet to direct it step-by-step towards its final destination. Each router makes a routing decision based on its routing tables and available paths.
The provided references consistently state that routers operate on the Network Layer (Layer 3) of the OSI model. They are the workhorse of this layer, making internet communication possible.
