A MAC address-based communication restricting method is disclosed. In the
MAC address-based communication restricting method, packet data is
received upon request of communication through an Ethernet switch, a MAC
destination address and a MAC source address of the received packet data
are read, it is determined whether access vectors of the MAC addresses
are present in an address entry table, and access is denied if the access
vectors (security keys) of the MAC destination and source addresses are
not matched.