This present disclosure describes path probe methods and devices. The methods comprise receiving a first path probe packet; establishing a first association according to link information in the first path probe packet and a path label of a network path to be probed; determining a third association based on an IP address in the first path probe packet and the path label of the network path to be probed. The IP address includes an IP address of an adjacent network node of the first network node, and a third association includes an association of the path label with the IP address of the adjacent node. The path probe method may reduce system overhead. In the transmission process, the number of network nodes may also be set according to needs. An IP overlay network based on label switching is realized.