Patent ID: 7269135

Claim:
A method for providing redundant connectivity between remote networks using a tunneling protocol, the method comprising: (a) providing a first switch in a master state and a second switch in a slave state between a first network and an intermediate network; (b) providing a third switch in the master state and a fourth switch in the slave state between a second network and the intermediate network; (c) from the first switch, advertising a route to a movable IP address associating the movable IP address with an interface on the first switch; (d) establishing incoming and outgoing paths and a tunnel over the paths between the first and third switches using the movable IP address as a tunnel endpoint and forwarding traffic between the first and second networks over the tunnel; (e) at the second switch, establishing an outgoing path with the third switch; (f) monitoring relative connectivity between the first network and the intermediate network provided by the first and second switches; and (g) in response to detecting that the connectivity of the second switch exceeds that of the first switch, dynamically transitioning the first switch to the slave state and the second switch to the master state, wherein transitioning the second switch to the master state includes associating the movable IP address with an interface on the second switch and establishing an incoming path and a tunnel with the third switch using the movable IP address as an endpoint, wherein monitoring relative connectivity includes monitoring relative connectivity on per VLAN basis.