Patent ID: 8848515

Claim:
A topology discovery method for use in a ring network comprising a first device and a first neighbor device adjacent to the first device, the method comprising: when determining to perform neighbor negotiation of the first device, sending, through a first port of the first device, a neighbor negotiation packet to the first neighbor device connected to the first port, wherein a second port of the first neighbor device is connected to the first port; receiving a neighbor negotiation reply packet returned by the first neighbor device, wherein the neighbor negotiation reply packet is generated according to an update result of link state information of the second port after the first neighbor device updates, according to the neighbor negotiation packet, the link state information of the second port; according to the neighbor negotiation reply packet, updating link state information of the first port in the first device; and according to an update result of the link state information of the first port, broadcasting a link state information base of the first device according to predetermined configuration to a set of devices including all the devices, except the first device, on the ring network, so that the set of devices update, according to the link state information of the first port, local link state information bases, wherein the link state information base comprises link state information of each port on the ring network.