Firewalls can restrict packets from unknown sources or change the priority of those packets. This can cause latency, patching issues, and problems connecting to Blizzard services.  To troubleshoot a router firewall, you will need to do the following using the documentation from the router manufacturer:
  • Factory reset the router to fix configuration errors
  • Update your router firmware to ensure that your router has the latest bug fixes and instructions

To troubleshoot a firewall for your operating system, select it below:

 

Windows®

  1. Press Windows+R
  2. Type Firewall.cpl into the run prompt, then press Enter.
  3. Click Restore Defaults from the menu on the left.
  4. Click the button to Restore Defaults
  5. Click Yes to confirm the prompt

The next time you use an application which would be blocked by Windows firewall, you should receive a prompt to allow the program through the firewall. Allow the game or application through the firewall to prevent further issues. If you continue to have firewall issues, ensure that your firewall is updated by running Windows Update.

macOS®

The firewall in Mac OS X and macOS allows you to control connections on a per-application basis, rather than a per-port basis. This makes it easier to use firewall protection and prevent undesirable applications from taking control of network ports.

  1. From the Apple menu, choose System Preferences > Security.
  2. Click the Firewall tab.
  3. Unlock the pane by clicking the lock in the lower-left corner and entering the administrator username and password.
  4. Click Start to enable the firewall.
  5. Click Firewall Options to customize the firewall configuration.
  6. Check the Automatically allow signed software to receive incoming connections box.
  7. Click OK.

Blizzard does not directly support proxies, firewalls, or routers. For assistance configuring your router or firewall, contact your ISP or hardware manufacturer. If you are using a third party firewall or proxy program, temporarily uninstall the program or contact the program's support team for configuration assistance.