LOOP DETECTION METHOD AND APPARATUS

Disclosed are a loop detection method and apparatus, which relate to the technical field of communications and solve the problem that using a non-standard LLDP packet carrying a user-defined specific protocol number causes conflict with other user-defined user packets in the prior art. A first device sends a first link layer discovery protocol LLDP data unit packet to a second device via a first port, the first LLDP packet comprising first loop detection information, the first loop detection information comprising loop detection type, the device identification of the first device and the port number of the first port; the first device acquires a second LLDP packet which is received from a second port and sent by the second device, the second LLDP packet comprising the first loop detection information, and the second port being a port different from the first port; and the first device determines that there is a loop between the first port and the second port. The embodiments of the present invention are appli