Multilayer switch definition
A multilayer switch (also known as a layer 3 switch) is a networking device that combines the functions of a traditional layer 2 switch with those of a Layer 3 router. Combining the functionalities of a router and a switch makes it a versatile and efficient component in modern computer networks.
See also: data transmission
How a multilayer switch works
- When data is sent from one device to another within a network, it is broken into small units called data frames. These frames arrive at the multilayer switch.
- The multilayer switch looks at the MAC (media access control) address on each data frame. MAC addresses are unique identifiers for each device on the network.
- If the data frame is meant for a device within the same local network, the switch uses its MAC address table to quickly determine which port the destination device is connected to — and forwards it directly to that port.
- If the data frame is meant for a device in a different network, the multilayer switch uses its routing capabilities. It looks at the IP address of the destination device to determine the best path for the data to reach its destination.
- If the data needs to move between different networks, the multilayer switch acts as a router.
Where multilayer switching is used
- Enterprise networks
- Data centers
- Campus networks
- Voice over IP and communications
- Wireless networks
- Security networks
