Method 1: Allow Local Network Access for Applications

When an app attempts to access the local network for the first time, macOS prompts a message such as:

"[AppName] would like to find and connect to devices on your local network."

If you denied access or want to verify permissions, follow these steps:

macOS 15 (Sequoia)

 1.   Open System Settings.

 2.   Go to Privacy & Security.

 3.   Scroll down to Local Network.

 4.   Find the app that needs local network access and toggle it on.

macOS 14 (Sonoma)

 1.   Open System Settings.

 2.   Navigate to Network.

 3.   Open Firewall.

 4.   If the Firewall is turned on open Option and Ensure the app is authorized to connect to the local network.

Reference:

• Control access to your local network on Mac

Method 2: Configure the Firewall to Allow Incoming Connections

If the firewall is active, it may block some local network connections. You need to configure it to allow traffic for the required applications.

macOS 15 & 14 (Sequoia & Sonoma)

 1.   Open System Settings.

 2.   Go to Network.

 3.   Select Firewall.

 4.   Click Options if the firewall is turned on.

 5.   Ensure the application is listed and allowed to accept incoming connections.

macOS 13 & 12 (Ventura & Monterey)

 1.   Open System Preferences.

 2.   Go to Security & Privacy.

 3.   Click the Firewall tab.

 4.   If the firewall is enabled, click Firewall Options.

 5.   Verify that the application is listed as allowed.

If it is not listed, click +, select the app, and choose Allow incoming connections.

Reference:

• Change Firewall settings on Mac

Method 3: Verify VPN Settings for Local Communication

Certain Wi-Fi networks or VPNs may block local traffic.

 1.   If using a VPN try temporarily disabling it to ensure it is not blocking local traffic.

Reference:

• About privacy and Location Services in macOS

Conclusion

After completing these steps, your application can:

• Scan the local network for devices.
• Communicate with other devices on the network.
• Avoid being blocked by firewall or security settings.