Switch

• An OSI layer 2 device
• Hardware bridging ASICs (very speedy!)
• Forwards traffic based on MAC address
• The center of an enterprise network
• High bandwidth - Many simultaneous packets

Layer 2 switching is considered hardware-based bridging because it uses specialized hard-
ware called an application-specifi c integrated circuit (ASIC). ASICs can run up to gigabit
speeds with very low latency rates.

Latency is the time measured from when a frame accesses a port to when it exits.

Bridges and switches read each frame as it passes through the network. The Layer 2
the device then puts the source hardware address in a filter table and keeps track of which port theframe was received on. This information (logged in the bridge’s or switch’s filter table)
is what helps the machine determine the location of the specific sending device.