Information
This setting determines the behavior for outbound connections that do not match an outbound firewall rule.
The recommended state for this setting is: Allow.
Note: If you set Outbound connections to Block and then deploy the firewall policy by using a GPO, computers that receive the GPO settings cannot receive subsequent Group Policy updates unless you create and deploy an outbound rule that enables Group Policy to work. Predefined rules for Core Networking include outbound rules that enable Group Policy to work. Ensure that these outbound rules are active, and thoroughly test firewall profiles before deploying.
Rationale:
Some people believe that it is prudent to block all outbound connections except those specifically approved by the user or administrator. Microsoft disagrees with this opinion, blocking outbound connections by default will force users to deal with a large number of dialog boxes prompting them to authorize or block applications such as their web browser or instant messaging software. Additionally, blocking outbound traffic has little value because if an attacker has compromised the system they can reconfigure the firewall anyway.
Impact:
None - this is the default behavior.
Solution
To establish the recommended configuration, set the following Device Configuration Policy to Allow:
To access the Device Configuration Policy from the Intune Home page:
Click Devices
Click Configuration profiles
Click Create profile
Select the platform (Windows 10 and later)
Select the profile (Endpoint protection)
Click Create
Enter a Name
Click Next
Configure the following Setting
Path: Endpoint protection/Microsoft Defender Firewall/Private (discoverable) network
Setting Name: Default action for outbound connections
Configuration: Allow
Select OK
Continue through the Wizard to complete the creation of the profile (profile assignments, applicability etc.)
Note: More than one configuration setting from each of the Configuration profiles (ex: Administrative Templates, Custom etc.) can be added to each Device Configuration Policy.
Default Value:
Allow (default). (The Windows Firewall with Advanced Security will allow all outbound connections in this profile unless there is a firewall rule explicitly blocking it.)