Firewall

This module controls your network rules. It works with a firewall already on your system, either ufw or firewalld. If neither is installed, it asks you to install one. Firewall type shows which one it's using.

#Turning it on

Use the switch at the top of the module to enable or disable the firewall.

If enabling it fails with a message that Iptables can't initialize after a kernel update, reboot your computer.

#Default policies

Default Incoming Policy and Default Outgoing Policy decide what happens to connections that no rule matches:

• Allow: Allows all connections.
• Ignore: Keeps the program waiting until the connection attempt times out, some short time later.
• Reject: Produces an immediate "Connection refused" message.

#Rules

The list shows your rules, with their Action, From, To, IP and Logging columns. Each rule has buttons to edit and remove it.

To add a rule, click Add Rule…. A simple rule has:

• Application with ufw, or Allow connections for with firewalld: The application or service the rule is for
• Policy
• Direction: Incoming or Outgoing

If the policy matches the default for that direction, the dialog points this out, since such a rule changes nothing.

Tick Advanced to set the rest:

• IP Version: IPv4 or IPv6
• Source and Destination: An address and port. Empty fields mean any IP address and any port.
• Protocol and Interface
• Logging: None, New Connections or All Packets

#Connections and logs

View Connections lists your computer's connections with their Protocol, Local address, Foreign address, Status, PID and Program. This needs the iproute2 or net-tools package.

View Logs lists the firewall's log entries with their From, Source port, To, Destination port, Protocol, Interface, Action, Time and Date.

In both, Blacklist Connection creates a rule from the selected entry.