A systems and method for gateway discovery and Layer-2 mobility is operable by an access terminal that connects to an access point. The access terminal determines security credentials and addressing and routing configurations used previously. The access terminal determines whether the security credentials may be reused by the access terminal to perform authentication with an access network and also determines whether the addressing and routing configurations may be reused by the access terminal. In a related system and method, a network entity receives an inquiry from an access terminal regarding whether a prior Trusted Wireless Access Gateway (TWAG) is reusable by the access terminal as a current TWAG. The network entity determines whether the prior TWAG is reusable and may send response to the access terminal indicating whether the prior TWAG is reusable.