Patent ID: 8125929

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 connection information comprises an identifier of a neighbor border node of a neighbor autonomous system (Router_ID) and a number of the neighbor autonomous system (AS Number), and wherein the border node of the autonomous system supports Intermediate System to Intermediate System (ISIS) protocol; flooding, by the border node of the autonomous system, the border connection information within the autonomous system, wherein the border connection information is included in a Link State Protocol Data Unit (LSP) message; and receiving, by a node of the autonomous system, the border connection information, wherein when border connection information is added on the border node, the process of flooding the border connection information within the autonomous system comprises: determining whether the LSP message comprises a TLV field available for adding the border connection information; if the LSP message comprises a TLV field available for adding the border connection information, including the added border connection information in the border connection description Sub-TLV field in the TLV field, refreshing the LSP message, and flooding the refreshed LSP message; and if the LSP message does not comprise a TLV field available for adding the border connection information, creating a new TLV field, including the added border connection information in a border connection description Sub-TLV field in the new TLV field, refreshing the LSP message, and flooding the refreshed LSP message.