In our network you have to use DHCP. This can be configured in your operating system, but usually, using DHCP is the default setting.
Every network interface of your computer or router (LAN port, WLAN-chip, Bluetooth-chip etc.) has a worldwide unique MAC address. We need the MAC address of your device in order to provide secure access to our network. Therefore you must provide the MAC address of the device you plug into the wall.