Patent ID: 8446876

Claim:
A method comprising: providing a plurality of mobility sub-domains for a network, each mobility sub-domain comprising one or more access switches that serve one or more Internet Protocol (IP) subnets each of which comprises a plurality of IP addresses; providing a controller apparatus in a first mobility sub-domain, a controller apparatus in a second mobility sub-domain and a central controller apparatus for the plurality of mobility sub-domains; receiving at the central controller apparatus from the controller apparatus in the second mobility sub-domain a mobile announce message indicating that a wireless device has roamed to and associated with a wireless access point on an access switch in the second mobility sub-domain; determining at the central controller apparatus that the wireless device roamed from a first mobility sub-domain where it was previously associated to a wireless access point on an access switch in the first mobility sub-domain, and which access switch in the first mobility sub-domain serves the IP subnet that includes an IP address of the wireless device; forwarding the mobile announce message from the central controller apparatus to the controller apparatus in the first mobility sub-domain; forwarding the mobile announce message from the controller apparatus in the first mobility sub-domain to the access switch in the first mobility sub-domain that serves the IP subnet that includes an IP address of the wireless device; sending traffic for the wireless device in a tunnel from the access switch in the first mobility sub-domain to a tunneling endpoint apparatus in the first mobility sub-domain; and sending traffic for the wireless device in a tunnel between the tunneling endpoint apparatus in the first mobility sub-domain and a tunneling endpoint apparatus in the second mobility sub-domain, and between the tunneling endpoint apparatus in the second mobility sub-domain and the access switch where the wireless device is currently attached in the second mobility sub-domain.