Ethernet Switches Ethernet switches are an expansion of the concept in Ethernet bridging. In the past, cut-through switches were faster because they examined the packet destination address only before forwarding it on to its destination segment. It takes more time to examine the entire packet, but it allows the switch to catch certain packet errors and keep them from propagating through the network. These are used to link switches together or give added bandwidth to high-traffic servers. Routers Routers filter out network traffic by specific protocol rather than by packet address.
Routers also divide networks logically instead of physically.
An IP router can divide a network into various subnets so that only traffic destined for particular IP addresses can pass between segments. Network speed often decreases due to this type of intelligent forwarding. Such filtering takes more time than that exercised in a switch or bridge, which only looks at the Ethernet address. However, in more complex networks, overall efficiency is improved by using routers. Network Design Criteria Ethernets and Fast Ethernets have design rules that must be followed in order to function correctly.