Data link layer-based communication method, device, and system

A network device, wherein the network device is applied to an autonomic network and comprises:

• a non-transitory memory storage comprising instructions;
• one or more hardware processors in communication with the non-transitory memory storage, wherein the one or more hardware processors execute the instructions to:
• generate, by the network device, an adjacency discovery (AD) message, wherein the AD message comprises a device identifier of the network device;
• and
• encapsulate, based on a frame at a data link layer, the AD message, 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 network device;
• a transmitter, configured to send, to a registrar device based on the destination data link layer address, the AD message that is encapsulated based on the frame at the data link layer, wherein the registrar device is a device that is in the autonomic network and that supports allocation of a domain certificate;
• a receiver, configured to receive a domain certificate sent by the registrar device, wherein the domain certificate is allocated by the registrar device to the network device according to the device identifier of the network device in the AD message;
• and
• wherein the one or more hardware processors execute the instructions to establish an autonomic control plane (ACP) with the registrar device according to the domain certificate.

A registrar device, wherein the registrar device is applied to an autonomic network, and the registrar device is a device that is in the autonomic network and that supports allocation of a domain certificate, and comprises:

• a receiver, configured to receive, from a network device, an adjacency discovery (AD) message encapsulated based on a frame at a data link layer, wherein the AD message comprises a device identifier of the network device, the frame at the data link layer comprises a source data link layer address and a destination data link layer address, the source data link layer address is a data link layer address of the network device, and the destination data link layer address matches a data link layer address of the registrar device;
• a non-transitory memory storage comprising instructions;
• one or more hardware processors in communication with the non-transitory memory storage, wherein the one or more hardware processors execute the instructions to:
• in response to determining that the network device is allowed to join the autonomic network, allocate a domain certificate to the network device according to the device identifier comprised in the AD message;
• a transmitter, configured to send the domain certificate to the network device;
• and
• wherein the one or more hardware processors execute the instructions to:
• establish an autonomic control plane (ACP) with the network device according to the domain certificate.