Introduction to SCADA Preprocessors

Note

This section applies to Snort 2 preprocessors. For information on Snort 3 inspectors, see https://www.cisco.com/go/snort3-inspectors.

Supervisory Control and Data Acquisition (SCADA) protocols monitor, control, and acquire data from industrial, infrastructure, and facility processes such as manufacturing, production, water treatment, electric power distribution, airport and shipping systems, and so on. The system provides preprocessors for the Modbus, Distributed Network Protocol (DNP3), Common Industrial Protocol (CIP), and S7Commplus SCADA protocols that you can configure as part of your network analysis policy.

If the Modbus, DNP3, CIP, or S7Commplus preprocessor is disabled, and you enable and deploy an intrusion rule that requires one of these preprocessors, the system automatically uses the required preprocessor, with its current settings, although the preprocessor remains disabled in the web interface for the corresponding network analysis policy.