Routers communicate with each other and share information that allows them to determine the best route through a complex internetwork that links many LANs. Switches Switches are another type of device used to link several separate LANs and provide packet filtering between them. With a different LAN connected to each of the switch's ports, it can switch packets between LANs as needed. Switches are used to increase performance on an organization's network by segmenting large networks into many smaller, less congested LANs, while still providing necessary interconnectivity between them. Switches increase network performance by providing each port with dedicated bandwidth, without requiring users to change any existing equipment, such as NICs, hubs, wiring, or any routers or bridges that are currently in place.
Switches can also support numerous transmissions simultaneously.
Deploying technology called dedicated LANs is another advantage of using switches. Using LAN switches allows a network designer to create several small network segments. These smaller segments mean that fewer stations are competing for bandwidth, thereby diminishing network congestion. In this case, that one station has an uncontested 100 Mbps Fast Ethernet LAN all to itself. Packets forwarded over it from other ports on the switch will never produce any collisions because there are no other stations on the LAN at that port.