What is a Layer 2 device and how does it work? Global Knowledge
An quick fundamental overview of layer two devices.
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A layer 2 device forwards a physical address. Most often, you’ll find a bridge and switch. A MAC Address is the address they use. Frames arrive at the device first by taking the source address and then placing it in the MAC Address List for 300 seconds (or five minutes).
It will then search for the destination address.
If the destination address is located, it will be forwarded at that port.
If the destination address cannot be found, it will forward it all to the ports of the VLAN to which the receiving interface belongs.
This is called flooding. Your MAC address table contains three important pieces of information:
Interface in which the frame was received
Each frame’s source MAC address.
The VLAN to interface.
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