Network switch and network switch system thereof

A network switch adapted for forming a single loop network, the network switch comprising:

• a plurality of connection ports, wherein each of the connection ports is in an enabled state or a disabled state by default to form the single loop network, each of the connection ports in the enabled state receives a data packet in the single loop network and forwards the data packet, and each of the connection ports in the disabled state receives the data packet in the single loop network but does not forward the data packet;
• and
• a processing circuit coupled to the connection ports and configured to determine whether the connection ports forming the single loop network are abnormal and determine whether any of the connection ports forming the single loop network receives a first abnormal message packet from other network switches, wherein when any of the connection ports receives the first abnormal message packet and one of the connection ports forming the single loop network is in the disabled state, the processing circuit sets the connection port in the disabled state to switch to the enabled state, and the processing circuit does not forward the first abnormal message packet in the single loop network, and when one of the connection ports forming the single loop network is abnormal and each of the connection ports forming the single loop network is in the enabled state, the processing circuit sets the abnormal connection port to switch to the disabled state, and transmits a second abnormal message packet to the other network switches in the single loop network through another connection port that is not abnormal,
• wherein the connection port in the enabled state directly switches to the disabled state without going through other port states, and the connection port in the disabled state directly switches to the enabled state without going through the other port states, and
• wherein the first abnormal message packet and the second abnormal message packet do not comprise a MAC address and an identifier (ID) of the network switch.