OPC UA

OPC UA parameters

Maximum client message size (bytes)	This value makes it possible to restrict the maximum size that an OPC UA client is allowed to send. It has to be between 8192 and 2147483647 (default value: 65535).
Maximum server message size (bytes)	This value makes it possible to restrict the maximum size that an OPC UA server is allowed to send. It has to be between 8192 and 2147483647 (default value: 65535).

Prohibit "None" security mode

If this option is selected, you will prevent the circulation of unencrypted and unsigned OPC UA traffic.

Managing OPC UA services

Public services

This table lists the codes and associated OPC UA services that have been predefined on the firewall. These codes are classified by operation set: Attribute, Discovery, Method, Monitored Item, Node Management, Query, Secure Channel, Session, Subscription and View.

Predefined OPC UA services are allowed by default (Allow action). The buttons Block by service set, Allow by service set and Modify all services make it possible to modify the action (Allow/Block) applied to the selected service set or to all OPC UA services listed in the table.

Other services allowed

This list allows authorizing additional OPC UA function codes blocked by default by the firewall. It is possible to Add or Delete elements to or from this list by clicking on the relevant buttons.

Support

Disable intrusion prevention	When this option is selected, the scan of the OPC UA protocol will be disabled and traffic will be authorized if the filter policy allows it.
Log every OPC UA query	Enables or disables the logging of OPC UA requests.