Software Secure Firewall Threat Defense
Platform Secure Firewall Threat Defense Virtual
Activity Onboard

Advanced Network Analysis and Preprocessing SCADA Preprocessors The DNP3 Preprocessor

Last updated: Jul 29, 2025

The DNP3 Preprocessor


 

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

The Distributed Network Protocol (DNP3) is a SCADA protocol that was originally developed to provide consistent communication between electrical stations. DNP3 has also become widely used in the water, waste, transportation, and many other industries.

The DNP3 preprocessor detects anomalies in DNP3 traffic and decodes the DNP3 protocol for processing by the rules engine, which uses DNP3 keywords to access certain protocol fields.