|  | 7.5 | Effects of Layer 2 Devices on Data Flow
| 7.5.4 | Router segmentation of a collision domain

Routers are more advanced than typical bridges. A bridge is passive (transparent) at the network layer and operates at the data link layer. A router operates at the network layer, and bases all of its forwarding decisions on the Layer 3 protocol address. It accomplishes this by examining the destination address on the data packet, then looking in its routing table for forwarding instructions. Routers create the highest level of segmentation because of their ability to make exact determinations of where to send the data packet.

Because routers perform more functions than bridges, they operate with a higher rate of latency. Routers must examine packets to determine the best path for forwarding them to their destinations. Unavoidably, this process takes time and introduces latency.