Methods and apparatus for maintaining a virtual private network connection

A client device establishes a virtual private network connection with a central site or network through a master concentrator. The master concentrator transmits state information, relating to the virtual private network connection, to a backup concentrator. In the event the master concentrator fails during a communications session between the client device and the network, the backup concentrator maintains the communication session between the client device and the network over the virtual private network connection using the connection state information received from the master concentrator. Such a configuration allows for failover of a virtual private network connection from the master concentrator to the backup concentrator without requiring the client device to re-establish the virtual private network connection with the central site or network. The configuration also allows the client device to maintain an existing communications session with the network.