Fault detection method of cross-segment network, communication system and related device

The embodiment of the invention discloses a fault detection method of a cross-segment network, a communication system and a related device, and belongs to the technical field of communication. The method comprises the following steps: a first forwarding node obtains the state of a BFD group, the BFD group comprises a BFD session of each path in a plurality of paths corresponding to the first forwarding node in a second segmented network, and the BFD session is used for detecting the fault of the corresponding path; and the first forwarding node notifies the second forwarding node of the fault conditions of the plurality of paths based on the state of the BFD group. Compared with a single-point fault detection mode, due to the fact that the fault conditions of the multiple paths are notified to the second forwarding node on the basis of the state of the BFD group, the embodiment of the invention provides a multi-fault-point detection mode of a cross-segmented network, and the flexibility of fault detection is