Patent ID: 6907470

Claim:
A packet communications apparatus to be used in a network system wherein user terminals that can be linked via a network to said apparatus send/receive packets to/from a server for authentication and a file server connected via a network to said apparatus, comprising: a plurality of network interfaces; a learned address table containing information for identifying one of said network interfaces through which to send a packet; a packet forwarding unit that selects a port through which to forward a packet by referring to said learned address table, according to the state of said network interfaces, and forwards or discards a packet sent from the user terminal, addressed to the server for authentication/file server and vice versa; a processor for directive packets to change state that receives a directive packet to change state, the packet holding a directive to change the state of a specific network interface to one of the connected state, disconnected state and stateless, via said packet forwarding unit from the server for authentication; and state managers, each installed in each network interface and each that receives a directive packet to change state from said processor for directive packets to change state and changes the state of the network interface to one of the connected state, disconnected state and stateless, according to the directive packet to change state.