A packet filter firewall filters packets based on the information in the TCP/IP headers. Especially, the TCP and UDP well known ports are important for filtering since they identify specific application processes.
In this game a firewall with 5 ports has to be controlled. The green ports indicate that packets are allowed to pass, whereas a red port signals that packets for this port have to be filtered by the firewall. The five well known ports are:
80: HTTP ((HyperText Transfer Protocol)
20: FTP (File Transfer Protocol)
443: HTTPS (HTTP Secure)
25: SMTP (Simple Mail Transfer Protocol)
If you press start you should decide which packets are allowed to pass the firewall. Please click on all packets that have to be filtered – they will be destroyed. Be careful – the firewall configuration changes during the game!