A method and apparatus are provided for configuring a VLAN on a node of a communication network. A graphical user interface (GUI) is provided at a network management system, through which an operator selects a node and a physical port on the node. The operator identifies which virtual ports associated with the physical port are to be included in each of the member set, the forbidden set, and the untagged set of the VLAN, up the GUI. The GUI is designed so that each virtual port can only belong to one of the member set and the forbidden set. In addition, the network management system ensures that a VLAN ID entered by the operator is unique, and that the maximum number of VLANs have not already been configured on the physical port. The configuration information is thereby validated, and sent to the node for configuration thereon.