Source address validation method, network device, and communication system

A source address validation method, comprising:

• sending, by a second network device, a first packet to a first network device, wherein the first packet arrives at the first network device through a newly added path on which the second network device serves as a source node and the first network device serves as a destination node, the first packet comprises newly added path information indicating the newly added path, the newly added path information indicates the first network device to add a source address validation (SAV) rule based on path information and the newly added path information, and the path information comprises a reachable path on which the first network device serves as a destination node.

A second network device, comprising:

• a processor;
• a memory storing program instructions, which, when executed by the processor, cause the second network device to:
• send a first packet to a first network device, wherein the first packet arrives at the first network device through a newly added path on which the second network device serves as a source node and the first network device serves as a destination node, the first packet comprises newly added path information indicating the newly added path, the newly added path information indicates the first network device to add a source address validation (SAV) rule based on path information and the newly added path information, and the path information comprises a reachable path on which the first network device serves as a destination node.