Why is OPC Classic considered firewall unfriendly?
Why is OPC Classic considered firewall unfriendly?
OPC Classic is considered firewall unfriendly because it uses DCOM (Distributed Component Object Model) which dynamically assigns any port between 1024 and 65535 for communication. This wide range of ports makes it difficult to configure firewalls to securely allow necessary traffic without exposing the system to potential security risks.
OPC Classic relies on Microsoft DCOM (Distributed Component Object Model) for communication. DCOM dynamically assigns ports for communication within the range 1024 to 65535, which makes it firewall-unfriendly
Answer A
A is correct answer. OPC Classic relies on Microsoft's Distributed Component Object Model (DCOM) and Remote Procedure Call (RPC) technologies, which dynamically assign TCP ports for communication between OPC clients and servers. DCOM/RPC can use any port number within the range of 1024 to 65535, meaning that a firewall would need to be configured to allow traffic on a vast number of ports, creating a significant security risk. The dynamic nature of OPC Classic's port usage makes it difficult to implement effective security measures with traditional firewalls, as they cannot be configured to allow traffic only for specific applications or services. OPC UA (OPC Unified Architecture) is a more modern and secure alternative to OPC Classic, as it uses a more predictable and secure communication protocol, making it easier to configure firewalls and implement security measures.