Patent ID: 7626937

Claim:
A system for detecting a connection status in a network, wherein the network comprises at least a first node and a second node, the system comprising: a request frame, transmitted by the first node, including a source address comprising a media access control (MAC) address of the first node; and a reply frame, transmitted by the second node after receiving the request frame, including a destination address comprising the MAC address of the first node, wherein the first node determines the connection status in a link layer according to whether receiving the reply frame, wherein the request frame and the reply frame are formed independent of an IP address, wherein if the second node comprises a network interface card (NIC), the second node transmits the reply frame only when a destination address of the received request frame comprises a MAC address of the second node, wherein if the second node comprises a network switch, the second node transmits the reply frame when the destination address of the received request frame comprises a MAC broadcast address; if the second node comprises the network switch, the second node selectively transmits the reply frame when the destination address of the received request frame comprises the MAC address of the second node.