Patent ID: 8270317

Claim:
A method for advertising border connection information of an autonomous system, comprising: establishing and maintaining, by a border node of the autonomous system, border connection information of the autonomous system, wherein the border node of the autonomous system supports Open Shortest Path First (OSPF) protocol, and the border connection information comprises an identifier of a neighbor border node of a neighbor autonomous system and a number of the neighbor autonomous system; flooding, by the border node of the autonomous system, the number of the neighbor autonomous system within the autonomous system; flooding, by the border node of the autonomous system, the identifier of the neighbor border node of the neighbor autonomous system within the autonomous system; and receiving, by a node of the autonomous system, the number of the neighbor autonomous system and the identifier of the neighbor border node of the neighbor autonomous system, wherein the node of the autonomous system supports the OSPF protocol, wherein the number of the neighbor autonomous system and the identifier of the neighbor border node of the neighbor autonomous system are included in value fields of two different border connection description sub-type-length-value (TLV) fields respectively, and each of the two border connection description sub-TLV fields is included in a Link TLV field of a Link State Advertisement (LSA) message, and wherein when border connection information is added on the border node, the process of flooding the number of the neighbor autonomous system and the identifier of the neighbor border node of the neighbor autonomous system of the border connection information within the autonomous system comprises: determining whether the LSA message comprises a Link TLV field available for adding the border connection information; if the LSA message comprises a Link TLV field, adding the border connection information in the Link TLV field, refreshing the LSA message, and flooding the refreshed LSA message; and if the LSA message does not comprise a Link TLV field, creating a new Link TLV field, including the added border connection information in the new Link TLV field, refreshing the LSA message, and flooding the refreshed LSA message.