VLAN Membership Methods

VLANs can be assigned to switch ports either statically or dynamically.

Static Assignment

Membership is port based. Switch ports are statically configured for specific VLAN. End-user devices are not aware if a VLAN exits. Configuration is also very simple. A single command assigns the port to specific VLAN.

Warning:  A port can be configured to one VLAN at a time. Both standard and extended range VLAN is supported but extended VLAN are not propagated by VTP and are only available if a switch is configured in VTP transparent mode. Newer Catalyst IOS releases allow creation of VLAN(s) on the fly. Previous versions required to create VLAN(s) in VLAN database and then assign ports to specific VLAN(s).

Step-1: configure terminal

Step-2: interface [range]

Step-3: switchport mode access

Step-4: switchport access vlan

Step-5: end


Verification: show vlan brief


Dynamic Assignment

Membership is based on MAC address of an end user device. When a device is connected to switch port, query must be made to establish VLAN membership. The MAC address to VLAN mapping is managed by central database namely: VLAN Membership Policy Server (VMPS). Typically Cisco Works is required to manage the dynamic assignment of VLANs.


Configuration is done in two steps. First specify the VMPS. Configure switch ports for dynamic assignment.


Step-1: configure terminal

Step-2: vpms server [primary]

Step-3: end

Verification: show vmps


Port Assignment for Dynamic VLANs

Step-1: interface

Step-2: switchport mode access

Step-3: switchport access vlan dynamic

Step-4: end

Verification: show vlan brief