LOOP DETECTING METHOD AND LOOP DETECTION DEVICE

PROBLEM TO BE SOLVED: To provide a method capable of detecting a loop detection without being conscious of neighborhood relation, and to provide a loop detection device. SOLUTION: One arbitrary switch 101 distributes a loop detection frame 111 by broadcast in a network. Upon receipt of the loop detection frame 111, a switch 102 checks whether an address defined to the own switch is registered at the frame or not. If the address is not registered, the switch 102 adds a MAC address of a sending-out interface to the last of the frame, and sends out the frame. When registration is discovered, it means that a loop is detected. Then, a detected interface is shut down, and loop detection is notified. COPYRIGHT: (C)2007,JPO&INPIT