PC-BSD® uses the to protect your system. By default, the firewall is configured to let your system make Internet connections, use the ping utility, and to communicate with other Windows and Unix-like systems using SMB and NFS.
Advanced users who are already familiar with pf will find the default rulebase in /etc/pf.conf. Users who are not familiar with directly editing this file can instead use the Firewall Manager GUI utility to view and modify the existing firewall rules.
To access the Firewall Manager, go to Control Panel → Firewall Manager or open an xterm and type pc-su pc-pfmanager. You will be prompted to input your password. Figure 8.67a shows the initial screen when you launch this utility:
The "General Settings" tab of this utility allows you to:
- determine whether or not the firewall starts when the system boots; unless you have a reason to do so and understand the security implications, this box should be so that your system is protected by the firewall
- start, stop, or restart the firewall: if you add, delete, or modify a firewall rule, restart the firewall for your changes to take effect
- restore default configuration: this button allows you to return to the original, working configuration should you not like the changes you make to your firewall rules
To view or modify the firewall rules, click “Exceptions” → “Add entry” to open the screen shown in Figure 8.16b.
The following information is needed when creating a rule:
- Service or Port: you can either select the name of the service you wish to allow or block from the drop-down menu or type in the number of the port used by the service. Which you choose does not matter as the firewall will match the name and number for you and display both after you save the rule. By default, the name “Custom” is selected for you and you only need to enter the port number.
- Policy: you need to choose whether to allow or block this service/port.
- Direction: use the drop-down menu to determine whether the policy applies to incoming or outgoing connections. The direction is from the perspective of your computer. Do you want others to connect to your service (incoming) or do you want to connect to the service running on another system (outgoing).
- Protocol: use the drop-down menu to select whether the service uses the TCP or UDP protocol.
- Interface: use the drop-down menu to select the interface that will make or receive the connection.
Once you have made your selections, press "Ok" to save the new rule.
Test that your new rule(s) work as expected. For example, if you create a rule to allow an SSH connection, try connecting to your PC-BSD® system using SSH to verify that the firewall is now allowing the connection.