A packet ring network system which includes a plurality of nodes connected to each other through two ringlets of a first direction ringlet and a second direction ringlet for forwarding packets in opposite directions to each other, the system comprising: a virtual redundant node which includes two adjacent nodes of a first node and a second node having a same address and acting as one combined node, wherein the first node firstly receives a first packet from the first direction ringlet and the second node firstly receives a second packet from the second direction ringlet; and a client device which is connected to each of the first node and the second node by respective links, wherein the client device is adapted to: determine, in accordance with a predetermined rule every time it sends a third packet which is to be forwarded from the client device, the first node or the second node as a destination node to send the third packet, and to send the third packet to the determined node in a normal state of the respective links, and send the third packet only to one of the first node and the second node connected to the link without a failure state, and wherein in a normal state of the respective links, the first node is adapted to permit the passage of a first dropped packet dropped from the first direction ringlet for sending to the client device and to prohibit the passage of a second dropped packet dropped from the second direction ringlet for sending to the client device, and the second node is adapted to permit the passage of the second dropped packet and to prohibit the passage of the first dropped packet, and wherein in a failure state of one of the links between the client device and the virtual redundant node, the first node and the second node are adapted to permit the passage of both the first dropped packet and the second dropped packet to be sent to the client device. a virtual redundant node which includes two adjacent nodes of a first node and a second node having a same address and acting as one combined node, wherein the first node firstly receives a first packet from the first direction ringlet and the second node firstly receives a second packet from the second direction ringlet; and a client device which is connected to each of the first node and the second node by respective links, wherein the client device is adapted to: determine, in accordance with a predetermined rule every time it sends a third packet which is to be forwarded from the client device, the first node or the second node as a destination node to send the third packet, and to send the third packet to the determined node in a normal state of the respective links, and send the third packet only to one of the first node and the second node connected to the link without a failure state, and wherein in a normal state of the respective links, the first node is adapted to permit the passage of a first dropped packet dropped from the first direction ringlet for sending to the client device and to prohibit the passage of a second dropped packet dropped from the second direction ringlet for sending to the client device, and the second node is adapted to permit the passage of the second dropped packet and to prohibit the passage of the first dropped packet, and determine, in accordance with a predetermined rule every time it sends a third packet which is to be forwarded from the client device, the first node or the second node as a destination node to send the third packet, and to send the third packet to the determined node in a normal state of the respective links, and send the third packet only to one of the first node and the second node connected to the link without a failure state, and wherein in a normal state of the respective links, the first node is adapted to permit the passage of a first dropped packet dropped from the first direction ringlet for sending to the client device and to prohibit the passage of a second dropped packet dropped from the second direction ringlet for sending to the client device, and the second node is adapted to permit the passage of the second dropped packet and to prohibit the passage of the first dropped packet, and wherein in a failure state of one of the links between the client device and the virtual redundant node, the first node and the second node are adapted to permit the passage of both the first dropped packet and the second dropped packet to be sent to the client device.