Configure Windows Firewall settings

If Windows Firewall is enabled on your OPC computers, you must allow certain programs through the firewall. The general guidelines for firewall configuration are to:

• Deny all incoming traffic to the OPC node (recommended).

• Allow incoming traffic from specific OPC nodes to TCP port 135.

• Allow incoming traffic from specific OPC nodes to the specific ephemeral TCP port range.

1. Click Start > Control Panel and double-click Windows Firewall.

2. On the Exceptions tab, enable exceptions for the following:

   • TCP Port 135 (Click Add port...)

   • Ephemeral ports (Click Add port... for each)

   • opcenum.exe (Click Add program...)

   • Your OPC server executable (Click Add program...)

3. To restrict the source of the incoming TCP connections to the OPC client node exclusively, click Change scope, enter the OPC client node’s IP address and click OK.