What are the steps for configuring a Linux firewall?

The steps to configure a Linux firewall are as follows:

1. Establishing firewall policies: deciding what network connections to allow or refuse from entering or exiting the system.
2. Install firewall software: Commonly used firewall software includes iptables and ufw, choose one to install.
3. Set up firewall rules: Establish rules for the firewall based on the policy, including allowing or denying specific network connections.
4. Start the firewall service: Activate the firewall software service to ensure the firewall is operational.
5. Test the firewall: Use different network connections to test if the firewall rules are effective, to ensure the security of the system network.

Please note that the steps above may vary depending on the firewall software used. For specific instructions, please refer to the official documentation or relevant guidelines for the firewall software being used.