as a first you should give secondary ip to your router's fastethernet/ethernet port, this secondary ip will one of your vpn ip subnet. Thanks to this way, your vpn users will learn how they can reach their destination. As I understood NT server 4...
and also you should add this line to your router :aaa authentication login NO_AUTHENT noneline con 0 login authentication NO_AUTHENT line vty 0 4login authentication NO_AUTHENT