Loop failure handling method and switch

A switch, comprising:

• a plurality of ports;
• a first memory is configured to store program code;
• and
• a processor coupled to the first memory and the plurality of ports, wherein the processor is configured to invoke the program code to perform:
• receiving a first packet comprising a source media access control (MAC) address, wherein the source MAC address is a MAC address of a device that generates the first packet;
• obtaining a first flapping count corresponding to the source MAC address, wherein the first flapping count indicates a quantity of times that the source MAC address flaps between different ports of the switch;
• determining, based on the first flapping count, whether a loop failure occurs in a network in which the switch is located;
• obtaining a flapping port set corresponding to the source MAC address when the loop failure occurs in the network in which the switch is located, wherein the flapping port set comprises a plurality of ports of the switch to which the source MAC address flaps sequentially;
• determining a primary port in the plurality of ports, wherein the primary port is a port that must be suppressed;
• and
• enabling a flooding suppression function on the primary port, wherein the flooding suppression function suppresses forwarding of a received flooding packet by the primary port.

A network system comprising a plurality of switches, wherein each switch comprises:

• a plurality of ports;
• a first memory configured to store program code;
• and
• a processor coupled to the first memory and the plurality of ports, wherein the processor is configured to invoke the program code to perform:
• receiving a first packet comprising a source media access control (MAC) address, wherein the source MAC address is a MAC address of a device that generates the first packet;
• obtaining a first flapping count corresponding to the source MAC address, wherein the first flapping count indicates a quantity of times that the source MAC address flaps between different ports of the switch;
• determining, based on the first flapping count, whether a loop failure occurs in a network in which the switch is located;
• obtaining a flapping port set corresponding to the source MAC address when the loop failure occurs in the network in which the switch is located, wherein the flapping port set comprises a plurality of ports of the switch to which the source MAC address flaps sequentially;
• determining a primary port in the plurality of ports, wherein the primary port is a port that must be suppressed;
• and
• enabling a flooding suppression function on the primary port, wherein the flooding suppression function suppresses forwarding of a received flooding packet by the primary port.