Control Ports and Free Ports

A port that is in a topology group can be a control port or a free port:

• Control port - A control port is a port in the master VLAN, and is therefore controlled by the Layer 2 protocol configured in the master VLAN. The same port in all the member VLANs is controlled by the master VLAN Layer 2 protocol. Each member VLAN must contain all of the control ports and can contain additional ports.
• Free port - A free port is not controlled by the master VLAN Layer 2 protocol. The master VLAN can contain free ports (in this case, the Layer 2 protocol is disabled on those ports). In addition, any ports in the member VLANs that are not also in the master VLAN are free ports.