A method includes: a first network device generates a data link layer-based autonomic control plane (L2 ACP) packet, wherein the first network device is an autonomic device in the autonomic network; encapsulates, based on a frame at a data link layer, the L2 ACP packet, wherein the frame at the data link layer comprises a source data link layer address and a destination data link layer address, and the source data link layer address is a data link layer address of the first network device; and sends, according to the destination data link layer address, the L2 ACP packet encapsulated based on the frame at the data link layer to a second network device, wherein the second network device is also an autonomic device in the autonomic network, and the second network device is a neighboring device of the first network device.