Internet Security

How To Check Apps Blocked By Firewall

Have you ever wondered why certain apps on your device are not working as expected? It could be due to a firewall blocking their access. Firewalls are essential security measures that protect our devices from malicious threats, but they can sometimes mistakenly block legitimate apps. So, how can you check if an app is being blocked by a firewall?

Understanding how firewalls work and how to troubleshoot their settings is crucial for identifying and resolving app blockages. By delving into the background and mechanics of firewalls, you can gain the necessary knowledge to navigate through their configurations and ensure that your desired apps are not being hindered. With this information, you can empower yourself to detect and resolve any app blocking issues caused by firewalls.



How To Check Apps Blocked By Firewall

Understanding Firewall and App Blocking

Firewalls are an essential component of network security, acting as a barrier between a trusted internal network and external networks, such as the internet. They monitor incoming and outgoing network traffic to determine whether to allow or block certain connections. Firewalls use various rules and settings to control the flow of data and ensure the security and privacy of the network.

In some cases, firewalls may unintentionally block certain applications from accessing the network. This can happen due to misconfigured settings or false positives where the firewall incorrectly identifies an application as a security threat. To ensure smooth network connectivity and enable the functioning of necessary applications, it is important to be able to check which apps are blocked by the firewall.

In this article, we will explore different methods to check for apps blocked by the firewall. We will discuss ways to identify blocked apps using built-in operating system tools, firewall logs, and third-party firewalls.

Checking Apps Blocked by Firewall in Windows

For Windows users, there are several ways to check which apps are blocked by the firewall. The Windows Firewall, built into the operating system, provides options to manage firewall rules and exceptions. Here are the steps to check for blocked apps:

Using Windows Defender Firewall

1. Open the Windows Defender Firewall settings by pressing the Windows key + R to open the Run dialog box. Type "control firewall.cpl" (without quotes) and press Enter.

2. In the Windows Defender Firewall window, click on "Allow an app or feature through Windows Defender Firewall" in the left-hand menu.

3. A list of apps and features will be displayed. Scroll through the list to identify any apps that are currently blocked by the firewall. Apps with a red "Blocked" label are blocked by default.

4. To unblock an app, check the box next to the app name and click the "OK" button.

5. If the app you are looking for is not listed, click the "Change settings" button at the top right of the window. Then, click the "Allow another app" button and browse for the app executable file (.exe) to add it to the list of allowed apps.

Using Event Viewer to Check Firewall Logs

Windows Firewall logs can provide detailed information about app blocking events. Follow these steps to access the logs using the Event Viewer:

1. Press the Windows key + R to open the Run dialog box. Type "eventvwr.msc" (without quotes) and press Enter to open the Event Viewer.

2. In the Event Viewer window, navigate to "Windows Logs" and expand it. Then, click on "Security" to view security-related events.

3. Look for events with the Source name "Microsoft Windows Security Auditing" and Event ID 5157. These events indicate blocked network connections by the firewall.

4. Double-click on the event to view more details, including the blocked app's path and IP addresses involved.

5. Use this information to identify the blocked app and take necessary actions to unblock it.

Checking Apps Blocked by Firewall in macOS

macOS users can utilize the built-in firewall along with other tools to check for blocked apps. Here's how to do it:

Using macOS Firewall

1. Open System Preferences by clicking on the Apple menu in the top-left corner of the screen and selecting "System Preferences."

2. In System Preferences, click on "Security & Privacy" and navigate to the "Firewall" tab.

3. Ensure that the firewall is turned on by clicking on the lock icon at the bottom-left corner of the window and entering your administrator password if prompted.

4. Click on "Firewall Options" to view the list of blocked apps. Apps with a checkmark next to their names are currently blocked.

5. To unblock an app, select its checkbox and click the "-" button. Alternatively, you can add a new app to the list by clicking the "+" button and browsing for the app.

Using Terminal to Check Firewall Logs

You can access firewall logs in macOS using the Terminal application. Follow these steps:

1. Open Terminal by navigating to "Applications" > "Utilities" > "Terminal."

2. In the Terminal window, type the command "sudo pflogsumm" (without quotes) and press Enter.

3. Enter your administrator password when prompted.

4. The Terminal will display a summary of firewall logs, including the blocked apps and associated IP addresses.

5. Use this information to identify the blocked app and make any necessary adjustments to the firewall settings.

Checking Apps Blocked by Firewall in Linux

Linux distributions often come with different firewall options, such as iptables or ufw (Uncomplicated Firewall). Here's how you can check for blocked apps:

Using Command-Line Tools

1. Open a terminal window by navigating to "Applications" > "System Tools" > "Terminal."

2. Use the appropriate command-line tool to check firewall rules and blocked apps. For example, to check iptables rules, use the command "sudo iptables -L" (without quotes).

3. The output will display information about currently blocked apps and their corresponding rules and IP addresses.

4. To unblock an app, use the appropriate command-line tool to remove the corresponding rule. For example, to remove an iptables rule, use the command "sudo iptables -D [chain name]" (without quotes), replacing [chain name] with the appropriate chain name and rule number.

Using GUI Firewall Configuration Tools

Alternatively, you can use GUI firewall configuration tools available for different Linux distributions, such as "gufw" for Ubuntu. Here's how:

1. Install the GUI firewall configuration tool for your distribution if it is not already installed. For example, to install gufw on Ubuntu, open a terminal and run the command "sudo apt-get install gufw" (without quotes).

2. Open the GUI firewall configuration tool from the application menu or by running the appropriate command in the terminal, such as "gufw" (without quotes)

3. In the GUI firewall configuration tool, you can view the list of currently blocked apps and adjust the settings accordingly.

4. Select the app you want to unblock and click the appropriate button, such as "Allow" or "Enable."

Additional Considerations

When checking apps blocked by a firewall, keep in mind the following:

  • Regularly review firewall settings and exceptions to ensure that necessary apps are not inadvertently blocked.
  • Consider consulting the documentation or support resources for your specific operating system and firewall configuration for detailed instructions.
  • If you are unsure about the impact of unblocking an app, consult with a network or security professional to ensure that the action does not pose any security risks.
  • Make sure to keep your operating system and firewall software up to date to benefit from the latest security features and bug fixes.

By following these steps and being vigilant about your firewall settings, you can effectively check and manage apps blocked by the firewall, ensuring seamless network connectivity and the secure operation of your system.


How To Check Apps Blocked By Firewall

Ways to Check Apps Blocked by Firewall

  • Check the Firewall Settings: Open the firewall settings on your device and look for the list of blocked apps or programs. Make sure that the firewall is not blocking any necessary apps.
  • Use the Event Viewer: Open the Event Viewer on your computer and go to Windows Logs > Security. Look for any blocked app or program events that indicate firewall activity.
  • Perform a Port Scan: Use a port scanning tool to check if any specific ports are being blocked by the firewall. This will help identify if any apps are being blocked due to port restrictions.
  • Check the Antivirus Software: Some antivirus programs include a firewall option. Check the settings of your antivirus software to ensure that the firewall is not blocking any apps.
  • Contact Network Administrator: If you are using a network or organization's firewall, contact the network administrator to see if any specific apps are being blocked by the firewall at the network level.

Key Takeaways - How to Check Apps Blocked by Firewall

  • To check apps blocked by the firewall, go to your firewall settings.
  • Look for a section called "Blocked Apps" or "App Permissions" in the settings.
  • In the blocked apps section, you will see a list of apps that are blocked by the firewall.
  • If you want to unblock an app, simply select it from the list and click "Allow" or "Unblock".
  • It's important to regularly check the blocked apps list to ensure that necessary apps are not blocked.

Frequently Asked Questions

In today's digital age, firewalls play a crucial role in network security by blocking unauthorized access to your computer or network. However, there may be instances when you need to check if certain apps are being blocked by your firewall. Here are some frequently asked questions about how to check apps blocked by a firewall:

1. How can I check if an app is being blocked by my firewall?

To check if an app is being blocked by your firewall, follow these steps:

  1. Open your firewall settings or control panel.
  2. Look for the list of blocked or allowed apps.
  3. Search for the app you suspect is being blocked.
  4. If the app is listed as blocked, you can either change the setting to allow it or create a new rule to allow the app through the firewall.
  5. If the app is not listed, it may not be blocked by the firewall, and you should consider other factors causing the issue.

2. Can I use Windows Security Center to check if an app is being blocked by the firewall?

Yes, Windows Security Center can help you check if an app is being blocked by the firewall. Follow these steps:

  1. Open Windows Security Center by clicking on the Windows Start menu and searching for "Security Center".
  2. In the Security Center window, click on "Firewall & Network Protection".
  3. Under "Firewall & Network Protection", click on "Allow an app through firewall".
  4. Scroll through the list of apps and check if the app you suspect is being blocked is listed.
  5. If the app is listed as blocked, you can change the setting to allow it through the firewall.

3. How do I check if an app is being blocked by the firewall on macOS?

To check if an app is being blocked by the firewall on macOS, follow these steps:

  1. Go to the Apple menu and select "System Preferences".
  2. Click on "Security & Privacy".
  3. In the Security & Privacy window, click on the "Firewall" tab.
  4. Click on the lock icon in the bottom left corner and enter your administrator password.
  5. Click on "Firewall Options" and look for the app you suspect is being blocked.
  6. If the app is listed as "Block incoming connections", you can change the setting to "Allow incoming connections" to unblock it.

4. Are there any online tools available to check if an app is being blocked by the firewall?

Yes, there are online tools available that can help you check if an app is being blocked by the firewall. These tools typically perform a scan of your network and analyze the communication between your device and the app's server. Some popular online tools include ShieldsUP! by GRC and Gibson Research Corporation and CanYouSeeMe.org.

Note that the use of online tools may require you to temporarily disable your firewall or allow the tool to bypass the firewall to perform the scan.

5. What should I do if I confirm that an app is being blocked by the firewall?

If you confirm that an app is being blocked by the firewall, there are a few steps you can take:

  1. Check if there are any specific firewall rules or settings that are causing the block. You may need to modify these rules to allow the app through.
  2. Ensure that the app is up to date and compatible with your operating system and firewall.
  3. If the app is essential for your work or personal use, consider contacting the app's developer or support team for assistance in resolving the issue.


In conclusion, checking which apps are blocked by your firewall is an important step in ensuring the safety and security of your computer or network. By following these simple steps, you can easily identify any apps that might be blocked and take the necessary actions to unblock them.

Remember to regularly review and update your firewall settings to keep your system protected from potential threats. It's always better to be proactive and address any issues before they become major security risks. If you're unsure about the best approach, consult with a professional or your IT department for guidance.


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