A method for providing single step log-on access for a subscriber to a computer network. The computer network is differentiated into public and private areas. Secure access to the private areas is provided by a Service Selection Gateway (SSG) Server, introduced between a conventional Network Access Server (NAS) and an Authentication Authorization and Accounting (AAA) Server. The SSG Server intercepts and manipulates packets of data exchanged between the NAS and the AAA Server to obtain all the information it needs to automatically log the user on when the user logs on to the NAS. An authorized user is thus spared the task of having to re-enter username and password data or launch a separate application in order to gain secure access to private areas of the network.