To access the internet with your laptop via the pool computer connect your laptop with an ethernet wire your brought and the LAN socket.
To make this work without problems the wire has to be in the laptop before you start the laptop. Only than the DHCP server will be started that will assign an IP address from the private section to the laptop.
After the login in system you have to start the program “/usr/local/bin/activate-laptop” with the command line (e.g. via ALT + F2 → xterm). Only after that step the laptop is allowed to access thee network.
This step is necessary to track who wants to access what with which IP at any time.