Patent ID: 8270412

Claim:
A network relay device, comprising: a transmit/receive unit having plural ports; a forwarding database (FDB) for storing as its registered contents at least: a port identifier for identifying each of the plural ports or a link aggregation group (LAG)_port into which are grouped a specified number of the plural ports; a terminal identifier for identifying a terminal; and an FDB_ID for being associated with both the port identifier and the terminal identifier; and an FDB_ID table for storing a value of the FDB_ID associated with the port identifier, along with an identification of the port identifier, wherein, when a command is generated to erase the registered contents of a specified port or LAG port stored in the FDB, the value of the stored FDB_ID associated with the port identifier identifying that port or LAG port is rewritten as another value, while retaining the FDB ID value stored in the FDB.