Top Free Network-Based Intrusion Detection Systems for Modern Enterprises

This document provides a concise overview of free network-based intrusion detection systems (NIDS), comparing leading open-source solutions—Suricata, Snort, Zeek, Security Onion, and Wazuh—by features, deployment considerations, and integrations. It highlights key detection capabilities, scalability, and practical use cases such as SOC augmentation, threat hunting, incident response, and compliance, and offers guidance on what to evaluate when selecting a free NIDS platform.