To access an L3 Switch, use a console connection. For network devices, use SSH, Telnet, or a web interface. However, you need to know the management IP address of the device. For a console connection, you can use tools like PuTTY or HyperTerminal. After connecting one end of the cable to the console port of your device, you should plug the other end into the serial port of your PC. Then, you can establish a link and configure it using terminal apps.