Patent ID: 7155536

Claim:
A method of controlling a router in an autonomous system, the router being in communication with other routers using an IS—IS protocol via interfaces and presenting: an active IS—IS protocol engine; and a standby IS—IS protocol engine; the method comprising: communicating with other routers via the active protocol engine; storing at least one of: data concerning the adjacency of the other routers, data concerning the state of links with the other routers, and data concerning the interfaces in a memory of the active protocol engine; updating the data stored in a memory of the standby protocol engine on the basis of the data in the active router concerning the adjacency, the state of the links, and the interfaces, wherein the data is updated if there is detection of at least one of: a modification to activating adjacency, a modification to deactivating adjacency, and modification to adjacency data due to receiving a packet declaring presence; and activating the standby protocol engine with the updated data, by using the IS—IS protocol with the other routers.