Dear Chantha, I wish it can help:
1. Each group VLAN must be bound to a principal VLAN.
2. If the VLAN ID has been used by the principal VLAN, this VLAN cannot be used for the VLANIF interface, supper-VLAN, or sub-VLAN.
3. An enterprise can use the principal port to connect to the enterprise server, a separate port to connect to enterprise customers, and a group port to connect to enterprise employees. Enterprise customers and employees can both access enterprise servers, enterprise employees can communicate with each other, enterprise customers cannot communicate with each other, and enterprise customers and employees cannot communicate with each other.
Have a nice day my friend!