A method provides subscriber-specific activation of network-based mobility management using an authentication server. According to the method, network-based mobility management is enforced, even if the mobile terminal supports terminal-based mobility management. This gives a network provider complete control over mobility management in his network, preventing configuration problems during the configuration of mobile terminals. In the method, after the successful authentication of a subscriber, the authentication server transmits an authentication confirmation message to an authentication client in an access network. The received authentication confirmation message contains an activation attribute for activating network-based mobility management, if the authentication server does not provide a common mobile key for terminal-based mobility management.