Avast Firewall is designed to be a more robust PC protection system than the default Windows Defender. It can monitor all the traffic going both into and out of your computer’s network and interject should any unknown or unwanted communications/intrusions take place.
It’s a very hands-off software requiring minimal input from you as a user, which is great!
But it’s not without issues. One common problem users report is that their Avast Firewall actually blocks their network and prevents access to other machines or the internet.
This is a fairly common problem and not too difficult to solve. Often, it just requires a simple reset of the software settings.
Table of Contents
- Why is Avast Firewall blocking network share?
- How to stop Avast Firewall from blocking network share
Much in the same way Windows Firewall and Windows Defender work, Avast Firewall has the authority to eject unwanted data being transferred across your network.
This kind of protection is very helpful when that data is from a malicious virus sending out personal information, but the firewall may actually start blocking data that we do want to transfer. In some cases, it will just block the entire network, making it completely unusable.
Let’s go through the primary things that might cause this issue, and then we’ll go through how to fix it.
Inbound/outbound traffic rules
Avast Firewall, much like Windows Defender, has the ability to use “rules,” which determine what programs have permission to transfer data into and out of your network.
In some cases, there may be an unintended rule preventing either a particular piece of software or the entire network from working correctly.
We can review all the active rules for Avast Firewall in the settings and either remove the unwanted rule or add an exception to allow that particular network or piece of software to function unhindered by the firewall.
Microsoft file sharing and printing
If a machine that has Avast Firewall installed on it cannot be accessed by other machines on the network, AVG (who are owned by the same parent brand as Avast) recommends enabling the Microsoft file sharing and printing function on the machine that cannot be accessed on the network.
By enabling this option, it will place a new rule in the firewall that marks the network as safe, allowing the firewall to grant access to the machine via the network.
As recommended by Avast support staff, updating your software can also sometimes fix this issue if it’s been caused by a bug or glitch in the programming.
If the software is up to date yet is still blocking network traffic without any obvious rules that would indicate why, it may be necessary to completely uninstall the software and re-install it.
There is also a helpful “repair” option that will check your installation for any corrupt or misplaced files. It will then correct these inconsistencies and help ensure the software is functioning smoothly.
Unfortunately, as programmers of malicious tools and viruses have gotten better, they have started to target firewall and antivirus software specifically to try and disable them so they can go about their business unimpeded.
It stands to reason, then, that you would want to both scan your computer and use the repair tool to make sure it’s free of any malicious software that might be affecting the firewall’s operation.
Turn off port scanning
Technically, there’s no reason why the port scanning feature should cause this. It’s simply known that when this feature is enabled, it can prevent the network from displaying correctly on that machine.
Likewise, Avast software has been known to affect the network by slowing it down.
Ensure the network is set to private
When your firewall profile is set to public, the settings are much more restricted, as they are intended for large user bases and adopt much more stringent rules that prevent network access.
By changing this back to a private network, your firewall will start to use those settings and allow your network to function as intended.
Turn off Windows Firewall
Just like antivirus software, we don’t generally need multiple firewalls running at once. In fact, it often does more harm than good, as they may conflict with each other.
In this case, disabling the default Windows firewall may allow the Avast firewall to function unimpeded.
As you can see, there are quite a few things that may cause Avast Firewall to block your network, and they span quite the range of settings, which can make it challenging to pin down the exact cause of the issue.
Fortunately, performing every adjustment and fix we are going to suggest here will not be detrimental to your machine in any way. Feel free to just follow along step by step until one of these methods works in freeing up your network.
Set the inbound/outbound traffic rules
Avast Firewall can create and use traffic rules to decide what access is allowed or blocked. If your Avast software is blocking your network, you can manually add an exception rule so the software knows to not block network access to any of your machines.
- Open Avast Antivirus and navigate to the firewall.
- Under the settings icon (the gear in the top right), click “view firewall rules.”
- Select the “network rules” tab.
- Ensure there is no rule currently blocking the network, and if there is, delete it.
- Then, add an exception rule for your network so Avast Firewall knows not to block it in the future.
Enable Microsoft file sharing and printing
If a machine you have Avast Firewall installed on cannot be accessed, enabling Microsoft file sharing and printing in your system services settings may allow it to be used within that network.
Please use the following steps:
- In Avast Antivirus, navigate to “tools” and then “firewall settings.”
- Under “profiles,” expand the menu and click on “system services.”
- Select “MS printer and file sharing service.”
- Change the “system rule details” under the action column to “allow for all.”
Repair Avast Firewall
Updating and repairing Avast Firewall can be a good way to fix any data that has become corrupt, or just generally work out any glitches in the software that are causing it to behave in an unwanted way.
To do this, open your Windows search bar and search for “apps & features.” Then, click the “programs and features” link on the top right-hand side.
From there, locate Avast Antivirus (which has the firewall module contained within it), and click the “repair” button.
This will check your installation, ensure it’s up to date, and fix any errors it may have detected.
Re-install Avast Firewall
If the software is up to date but is still having the issue, it may be necessary to completely uninstall and reinstall it fresh.
Unfortunately, this will remove all your user settings, so you might want to jot them down before proceeding.
Use an uninstaller like IObit Uninstaller, which will automatically remove any residual files and registry entries that are left behind.
Re-download the software from the Avast website, and set it up as normal.
Scan for malicious software
As we know, sometimes viruses and malware tools can affect the operation of antivirus and firewall software.
Giving your computer a comprehensive scan to remove any malware may help restore your firewall to functioning order if it was being affected by a virus.
Turn off port scanning
There is a known bug within Avast Firewall where the port scanning feature can automatically cause it to block certain IP addresses on your network.
This can be disabled through the Avast Firewall menu by navigating to “advanced” and then unchecking the “port scan detection” feature.
Change network to private
If upon checking your current Firewall profile within the Avast software you notice it’s set to “public network,” it may be using an undesired firewall ruleset and should be changed back to “private network.”
This can be done from the Avast antivirus menu by clicking on Avast Firewall and then navigating to your currently selected profile.
Turn off Windows Firewall
If your Windows Firewall is having conflicting issues with Avast, it’s not necessary to have them both enabled at the same time. Turning one of them off can often solve many issues that are caused by having multiple firewalls operating on a single machine.
Use the following steps to disable Windows Firewall:
- Using your search bar, locate the control panel.
- Click on “system and security.”
- Next, click “Windows Defender Firewall.”
- Down the left-hand panel, locate “turn Windows Defender Firewall on or off,” and click it.
- Click the “turn off Windows Defender Firewall (not recommended)” bubble.
- Click OK to finish.