1. An apparatus, comprising: a storage medium that stores a packet forwarding database structured as a graph of nodes (graph of FDB nodes), each FDB node including a media access control (MAC) address, a Virtual Local Area Network (VLAN) instance identifier, and an egress port number, a first graph of VLAN nodes, wherein each VLAN node includes a respective VLAN instance identifier and a respective pointer to a first graph of port nodes associated with the VLAN instance identifier, and a second graph of port nodes, wherein each port node includes a port number and a pointer to a second graph of VLAN nodes associated with the port number, wherein each port node in the first graph of port nodes is paired with a corresponding VLAN node in the second graph of VLAN nodes, and each pair of port node and VLAN node includes a pointer to an FDB node with a corresponding VLAN instance identifier and egress port number; means for obtaining a VLAN instance identifier as a first search key; means for obtaining a port number as a second search key; and means to manipulate the packet forwarding database given one of the first search key with which to search the first graph of VLAN nodes and a second search key with which to search the second graph of port nodes.