Patent ID: 7689722

Claim:
A method for providing redundancy at a virtual private network gateway, the method comprising: identifying one of a plurality of VPN gateways as a primary VPN gateway and another as a secondary VPN gateway, the plurality of VPN gateways coupling a private network to a public network, wherein the plurality of VPN gateways have a plurality of distinct actual IP addresses; setting the primary VPN gateway as the active VPN gateway; assigning a virtual IP address to the plurality of VPN gateways, wherein the plurality of VPN gateways are configured to share the same virtual IP address, wherein a client associated with the public network communicates with an entity on the private network by using the assigned virtual IP address; using the virtual IP address during a key exchange sequence with the client associated with the public network before allowing a client associated with the public network to access an entity on the private network; determining that the primary VPN gateway has failed; setting the secondary VPN gateway as the active VPN gateway, wherein the secondary VPN gateway continues serving VPN tunnels established by the primary VPN gateway without renegotiating IPsec sessions; and injecting a reverse route into the private network using a plurality of link state packets, the plurality of link state packets including the virtual IP address.