Directing network packets based on the layer 3 address of their destination. In IP networks, the IP address is the layer 3 address.

This means that IP routing is a form of layer 3 switching; but the simple hardware alluded to by the jargon use of "layer 3 switching" is meant to replace the slower software processing used by common routers. The speed enhancement will be essential to replacing existing 100-mbit routing systems with multi-gigabit systems, which will become critical for ISPs when the last mile starts to go to 100-mbit or gigabit speeds. It can also allow further concentration of the existing network, which reduces overall costs.

Like routers, layer 3 switches may also apply QoS to the packets, prioritizing traffic according to the parameters of its account and the state of the network.

Log in or register to write something here or to contact authors.