What undermines the use of traditional firewalls with OPC Classic?

The use of traditional firewalls with OPC Classic is notably undermined by dynamic TCP port assignment. OPC Classic operates using multiple dynamic ports for its communication, which can change frequently and are not fixed. This poses a significant challenge for traditional firewalls, which typically rely on static rules to allow or deny traffic based on predetermined ports.

Because the port assignments are dynamic, firewalls that are configured with a specific set of rules for static ports may block legitimate traffic, resulting in communication issues. In contrast, techniques or solutions that can manage or accommodate dynamic port assignment are necessary for effectively securing OPC Classic environments. Being able to adapt to changing port requirements is crucial for maintaining proper communication and ensuring the operational continuity of the systems involved.

Options like static IP assignments, restricted user access, and high data volume do not directly impact the fundamental capability of traditional firewalls to handle traffic. Static IP assignments simplify network management and firewall configurations since they do not change, and restricted user access is more related to access control rather than which ports are used for communication. High data volume can challenge performance but does not specifically disrupt the firewall's fundamental operation as dynamic port assignments do.