Abstract: A derived virtual local area network (VLAN) mapping technique enables centralized control of broadcast domains by a switch capable of supporting different protocols carried within frames that are distributed throughout a computer internetwork. Associated with each incoming frame received at the switch are characteristics such as protocol type and/or subnet information, and associated with each input port of the switch are characteristics such as VLAN and/or index values. Utilizing certain of these characteristics, a derived VLAN value is generated that allows users to create arbitrary VLAN domains and reduce broadcast traffic received by stations of the domains.