How to Enable/Disable UFW Firewall on Ubuntu 18.04 & 20.04?


In the world of technology, security is a top priority for all users. One of the most important aspects of security is a firewall, which helps to protect your computer from unauthorized access and potential attacks. Ubuntu 18.04 and 20.04 come with a built-in firewall tool called UFW (Uncomplicated Firewall), which is designed to be easy to use, even for beginners.

UFW Firewall is an essential component of the Linux operating system and can be used to configure network traffic rules on your Ubuntu server or desktop. It can help you to secure your system by blocking incoming connections or allowing only the services you need.

Why it's important to enable/disable UFW Firewall?

The UFW Firewall plays a significant role in securing an Ubuntu system. By default, it blocks all incoming traffic while allowing outgoing traffic.

Therefore, it's crucial to enable or disable this firewall based on your specific needs and requirements. For example, if you want to run a web server on your Ubuntu machine, you'll need to allow incoming HTTP/HTTPS connections by enabling UFW Firewall for these ports (80 and 443).

On the other hand, if you're not running any services that require external access, disabling UFW may provide better performance as it will reduce unnecessary overheads. Moreover, enabling/disabling UFW Firewall provides another layer of defense against cyber-attacks that could compromise sensitive data stored on your computer or network devices connected over LAN /WiFi.

Enabling UFW Firewall on Ubuntu 18.04 & 20.04

Installing UFW Firewall

Before enabling UFW firewall, ensure that it is already installed or install it if not yet installed. The following command will install UFW firewall −

sudo apt-get install ufw

You need to enter your password when prompted to continue with the installation process.

Checking the Status of UFW Firewall

After installing UFW firewall, check its status using the following command in your terminal −

sudo ufw status

The output will show the current status of the firewall and rules that are currently active.

Enabling UFW Firewall using Command Line Interface

To enable the UFW firewall and start protecting your system from malicious traffic, run the following command in your terminal −

sudo ufw enable

After running this command, you will see a message confirming that "Firewall is active and enabled on system startup". If you check its status again using sudo ufw status, you should see that it is now being enabled.

Screenshots and Examples for Each Step

Here's a screenshot example for checking the status of UFW firewall: ![UFW Status Screenshot]( And here's an example of how to enable UFW firewall using CLI −

![Enable UFW Screenshot]( Following these steps should ensure that your Ubuntu 18.04 & 20.04 system is now protected by a reliable and effective firewall solution!

Disabling UFW Firewall on Ubuntu 18.04 & 20.04

Disabling the UFW Firewall may be necessary in certain situations, such as when troubleshooting network issues or when installing software that requires open ports. Fortunately, disabling the firewall is a straightforward process that can be accomplished using a few simple commands in the terminal.

Step-by-Step Guide to Disable UFW Firewall

To disable UFW Firewall on Ubuntu 18.04 & 20.04, follow these steps −

  • Open a terminal window by pressing Ctrl+Alt+T or searching for “Terminal” in the application dash.

  • Type the following command to stop all firewall rules −

sudo ufw disable
  • The terminal will prompt you for your password. Enter it and press Enter.

  • You will receive a message that says “Firewall stopped and disabled on system startup” confirming that UFW has been successfully disabled.

It’s important to note that disabling the firewall can leave your system vulnerable to attacks from outside sources, so it’s advised to only disable the firewall temporarily and re-enable it once you’ve completed your task.

Common Issues with Enabling/Disabling UFW Firewall on Ubuntu 18.04 & 20.04

Rules Conflict and Syntax Errors

When enabling/disabling UFW Firewall on Ubuntu 18.04 & 20.04, one of the most common issues that users encounter is a conflict between firewall rules or syntax errors in the command line interface. This problem arises when users fail to follow correct syntax for commands, or they create conflicting rules that prevent firewall from functioning correctly. To troubleshoot this issue, you need to verify the syntax of each command before executing it to enable/disable UFW Firewall.

Always ensure you input commands accurately and do not omit any essential characters or spaces in-between words. Additionally, check for any conflicting rules by listing all the active rules using 'sudo ufw status verbose' and reviewing them one by one to identify inconsistencies.

sudo ufw status verbose

Applications are Blocked by Default

Another common issue with enabling/disabling UFW Firewall on Ubuntu is that some applications may be blocked by default when you enable firewall settings as they are not whitelisted yet in your configuration files. This can cause trouble for specific applications like certain games or multimedia software that depend on specific ports and protocols that are blocked by default.

To fix this issue, first identify which ports and protocols your application uses then add them individually using 'sudo ufw allow {port}/{protocol}' command where {port} is the port number used by the application, and {protocol} is either TCP or UDP type of protocol being used (or both if needed). If unsure about which port numbers should be allowed for a particular application/service - research online or contact their support team for guidance specifically for their software product running on Ubuntu OS with UFW Firewall enabled.

Enabling/disabling UFW Firewall on Ubuntu 18.04 & 20.04 is an essential step towards maintaining the security and integrity of your system. With the prevalence of cyber-attacks and malicious software, it's crucial to take proactive measures to protect your system from potential threats.

By enabling UFW Firewall, you're creating a barrier between your system and outside networks, restricting access to unauthorized users and potentially harmful traffic. Disabling UFW Firewall may be necessary in certain circumstances where specific applications or services require unrestricted access to external networks.


However, it's important to remember that disabling the firewall entirely exposes your system to potential security risks that can compromise the confidentiality and integrity of sensitive data. In today's digital age where information is power, protecting your system from external threats is a critical aspect of ensuring optimal performance and functionality.

By following the steps outlined in this article on how to enable/disable UFW Firewall on Ubuntu 18.04 & 20.04, you can create a secure environment for your system while still maintaining connectivity with external networks when necessary. As technology continues to evolve and new security threats are discovered, it's essential to stay up-to-date with best practices for safeguarding your systems against attacks.

By taking a proactive approach towards security measures like enabling UFW Firewall on Ubuntu, you can mitigate potential risks before they have a chance to impact your operations negatively. So take action today by implementing these measures in your own environment and rest easy knowing that you're doing everything possible to protect yourself against cyber-attacks and other malicious activities online!

Updated on: 08-Jun-2023


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