A network device receives an Ethernet frame, checks a destination media access control (MAC) address based on a first cyclic redundancy check (CRC) code, to determine whether an error occurs in the destination MAC address. If the network device determines that no error occurs in the destination MAC address, the network device forwards the Ethernet frame based on the destination MAC address. The Ethernet frame includes the destination MAC address, the first CRC code, and a payload, a parameter of the first CRC code includes the destination MAC address, and the parameter of the first CRC code does not include the payload.