A router is a Layer 3 device, operating within the Network Layer of the OSI model. Routers primarily focus on directing data packets between different networks by examining the IP addresses in the packets. They use routing tables to determine the best path for each packet based on its destination address.
Here's a breakdown of why routers reside in Layer 3:
- Layer 3: Network Layer: This layer deals with logical addressing, routing, and packet forwarding across networks. Routers are responsible for finding optimal paths for data packets to travel between networks.
- Layer 2: Data Link Layer: This layer handles physical addressing (MAC addresses) and error detection within a local network. While routers use MAC addresses for local communication, their primary function lies in routing packets between networks, making them a Layer 3 device.
Think of it like this: imagine you're sending a letter to someone in a different city. The router is like the postal service, figuring out the best route for your letter to reach its destination.
