Systems and methods are described for managing network connectivity for mobile users, particularly when a mobile user roams between two networks or between two subnets of a network. An announcer signal is broadcast by a host organization. The announcer signal includes a network identifier, an authorizer address and a verifier address. A mobile client monitors for the announcer signal and, when detected, provides an option to connect to the network via the authorizer. Once authorization is obtained, the mobile client communicates with the network through the verifier. The verifier received tagged data packets from a mobile client and only accepts the data packets if a valid tag (created with an authorization key) is included therewith. Multiple verifiers may be used to provide load balancing and fault tolerance (in the event a verifier fails). If a mobile client disconnects from a network and later reconnects, the mobile client does not have to be re-authorized if the mobile client still has a valid authorization key.