Manage Firewall

If ufw (Uncomplicated Firewall) is not found when you try to use it with sudo, it typically means that ufw is not installed on your system. Here’s how you can install and use ufw on Ubuntu:

Installing ufw on Ubuntu

1. Update Package Index:

   sudo apt update
   

2. Install ufw:

   sudo apt install ufw
   

3. Verify Installation: After installation, you can verify ufw is installed correctly by checking its version:

   ufw --version
   

Using ufw to Manage Firewall Rules

Once installed, you can use ufw to manage your firewall settings. Here are some common commands:

• Enable Firewall:

  sudo ufw enable
  

• Disable Firewall:

  sudo ufw disable
  

• Allow Incoming SSH Connections (if SSH is your primary access method):

  sudo ufw allow OpenSSH
  

• Allow Other Services (replace service_name with the service name or port number):

  sudo ufw allow service_name
  

• Deny Connections (to block a specific port):

  sudo ufw deny service_name
  

• Check Firewall Status:

  sudo ufw status
  

• Reset Firewall (disable all rules and reset to default):

  sudo ufw reset
  

Additional Notes

• Ensure that ufw is installed on your Ubuntu system using the steps mentioned above. If you encounter any issues during installation, check your system’s repository and network connectivity.
• After installing ufw, you may need to configure it according to your specific security requirements, allowing only necessary services and ports as per your application's needs.

By following these steps, you should be able to install and use ufw to manage firewall rules on your Ubuntu system effectively.