52 Chapter 1 About Ethernet Switches 325 and 425320985-A Rev 01VLAN Configuration ControlVLAN Configuration Control (VCC) is a new feature in Software Release 3.6 thatallows a switch administrator to control how VLANs are modified. VLANConfiguration Control is a superset of the existing AutoPVID functionality andincorporates this functionality for backwards compatibility. VLAN ConfigurationControl is globally applied to all VLANs on the switch.VLAN Configuration Control offers four options for controlling VLANmodification:1 Strict — This option restricts the addition of an untagged port to a VLAN if itis already a member of another VLAN. To add an untagged port to a newVLAN, the switch administrator must remove the port from all other VLANsof which it is a member of before adding it to the new VLAN. The PVID ofthe port will be changed to the new VID to which it was added.2 Automatic — This option automatically adds an untagged port to a newVLAN and automatically removes it from any previous VLAN membership.The PVID of the port is automatically changed to the VID of the VLAN itjoins. Since the port is first added to the new VLAN and then removed fromany previous membership, the Spanning Tree Group participation of the portwill not be disabled as long as the VLANs involved are in the same SpanningTree Group.3 AutoPVID — This option functions in the same manner as previousAutoPVID functionality. When an untagged port is added to a new VLAN,the port is added to the new VLAN and the PVID assigned to the new VIDwithout removing it from any previous VLAN memberships. Using thisoption an untagged port can have membership in multiple VLANs.4 Flexible — This option functions in a similar manner to disabling AutoPVIDfunctionality. When this option is used, there are no restrictions on thenumber of VLANs to which an untagged port can belong. Any new additionsof an untagged port to a new VLAN does not change the PVID of that port.1Note: Strict is the factory default setting.
