Firewall Settings in OPC UA Server

OPC UA has been designed to be firewall-friendly. HTTP/S traffic uses well-known (and generally permitted) ports. The OPC.TCP transport protocol is designed to use a single port.

The purpose of the firewall is to block incoming traffic that is unsolicited, or traffic that does not correspond to the exceptions set in the firewall. With OPC UA, only the server computer requires a firewall exception, since OPC UA does not require callbacks.

In particular, the Local Discovery Server (LDS) is accessible on the standard port 4840 and the UA wrapper uses the port 48400 (OPC.TCP) and 48401 (HTTP). So, these ports should be enabled in the firewall.