Firewall

Access this feature from: Protection ▸ Firewall

Firewall monitors all network traffic between your PC and the outside world to protect you from unauthorized communication and intrusions. This feature is designed to require minimal input from you. To ensure you are protected, all you need to do is keep Firewall turned on and, when prompted, select the appropriate Firewall profile for each network that you connect to:

Private: if you trust the network (for example, your home network).
Public: if the network is publicly shared (for example, the network at a cafe or airport).

These profiles control the settings, which determine how strictly Firewall protects your PC.

Note: Firewall is available in Avast Ultimate and Avast Premium Security only.

Manage Firewall activity

To ensure maximum security, Firewall is enabled by default. We recommended you keep Firewall turned on at all times unless you need to temporarily disable it for troubleshooting purposes.

To disable Firewall, click the ON slider and select a listed time duration. The slider then switches to OFF. We do not recommend stopping Firewall permanently by selecting the Stop indefinitely option.

Manage Firewall profiles

Each network that you are connected to appears under the heading Current network. In the Firewall profile column, select the appropriate profile for each network:

Private: a lower level of security, suitable for when your PC is connected to a trusted network, such as your home or work network. This profile enables better connectivity, and permits all communication within the network.
Public: a higher level of security, suitable for when your PC is connected to a public network, such as in a cafe or airport. Because public networks present greater security risks, no incoming communication is permitted when this profile is set.

Each time you access a known network, Avast remembers and applies the applicable Firewall profile (as previously set by you). Each time you connect to a new network, Avast prompts you to select the appropriate profile. The default profile setting when no profile is selected is Public.

View recent Firewall activity

Under Apps recently managed by your Firewall, you can see the system and non-system apps that Firewall has recently Allowed or Blocked from communicating with your PC. For most users, these details are entirely informational.

When you are connected to a Private network, most apps are Allowed because fewer Firewall restrictions are imposed. When you are connected to a Public network, more apps are Blocked because the protection level is higher. If an app is blocked while you are connected to a Private network, Firewall has detected and blocked suspicious communication attempts. No actions are required from you.

Modify Firewall settings

Click Settings under the Firewall Profile column on the Firewall feature screen, or go to ☰ Menu ▸ Settings ▸ Protection ▸ Firewall to access the following advanced settings:

Enable or Disable Firewall: to disable Firewall temporarily for troubleshooting purposes, click the ON slider and select a listed time duration. We do not recommend stopping Firewall permanently by selecting the stop indefinitely option. To enable Firewall, click the OFF slider so that it changes to ON.
Show notification about newly created 'allow' rules: tick this option to send an alert message each time a new rule related to authorizing communication is created by the auto-decide feature. Ticking this option may result in frequent and potentially obtrusive alerts.
Application rules: use the drop-down menu to define the behavior of Avast when it detects a program without previously defined application rules. Read more...
System Rules: allows expert users to review and configure predefined system rules. Read more...
Packet Rules: allows expert users to review, customize, and add new packet rules. Read more...
List of network profiles: displays the list of networks you're connected to. Use the drop-down menu to define the Firewall profile for each network.

Note: only make configuration changes if you have an advanced understanding of firewall principles.

Troubleshoot issues

We recommended you keep Firewall enabled at all times. If you need to temporarily disable it, for example, to check if an application is being blocked, click the ON slider and select a listed time duration. The slider then switches to OFF. We do not recommend you turn this feature off indefinitely by selecting the Stop permanently option.