Patent ID: 7764696

Claim:
A routing control method comprising: monitoring, by a first router, a status of a connection with an external network and when the connection is to be cancelled, transmitting, by the first router, a routing stop message notifying a routing stop router time, as a time remaining until a stop of a routing function of the first router, to nodes in a local area network to which the first router is connected; determining, by a second router, a routing capability time required to enable the routing function when the second router is configured to execute the routing function; transmitting, by the second router to the nodes in the local area network to which the second router is connected, a routing capability message that includes the routing capability time; and setting a time for switching, by the nodes receiving the routing stop message and the routing capability message, a destination of transmissions from the first router to the second router based on the routing capability time inside the routing capability message, wherein the routing capability time is determined in and transmitted from the second router.