Vlan Tagging

See VLAN (Virtual Local Area Network)

A lot of the time, the traffic can be form mulitple Virtual Switch (vSwitch) or Network Switch.

We use vLAN tagging to specify where the traffic coming from. It stamp the vLAN number to the network packet before it's sent out from the switch.

Therefore the end receiving will know which VLAN packet belongs to.

It's to group the packet and filter