Security Onion
Free Linux distribution bundling network monitoring, intrusion detection, and log management.
What Is Security Onion?
Security Onion is a Linux distribution that installs a complete network security monitoring stack, including Suricata and Zeek for network detection and metadata, Elastic for storage and search, and its own management interface for alerts, dashboards, and hunting. It also supports host telemetry such as Sysmon and osquery data, and it includes an intrusion detection honeypot (IDH) node option. Paid support, training, and the Security Onion Pro edition come through Security Onion Solutions.
Use Cases
Standing up full NSM capability on your own hardware without assembling the stack component by component.
Strengths and Limitations
Strengths
- +Curated suite of tools designed to work together instead of a parts list.
- +Same interface covers alerts, dashboards, PCAP, and hunt.
- +Scales from a single node to distributed grids.
Limitations
- -Hardware requirements are substantial for full packet capture.
- -The Elastic License 2.0 bars providing the software to third parties as a hosted or managed service.
Defensive Use
Network and host telemetry collection with integrated detection for teams building their own SOC visibility.
Security Onion Alternatives
| Tool | License | Platforms | Pricing |
|---|---|---|---|
| Arkime Full packet capture and indexing platform for storing, searching, and inspecting PCAP files across large enterprise networks. | Apache-2.0 | Linux, FreeBSD | Open Source |
| Elastic Security SIEM and XDR built on the Elastic Stack with open detection rules and endpoint integration. | Elastic-2.0 (Security solution, detection rules); AGPL-3.0-only OR SSPL-1.0 OR Elastic-2.0 (Elasticsearch, Kibana core) | Web, Linux, macOS, Windows | Free / Commercial |
| Suricata Multi-threaded network intrusion detection, prevention, and security monitoring engine with application-layer protocol parsing. | GPL-2.0-only | Linux, FreeBSD, macOS, Windows | Open Source |
| Wazuh Open-source SIEM and XDR platform providing endpoint monitoring, log analysis, file integrity checks, and threat detection. | GPL-2.0-only WITH OpenSSL-exception | Linux, Windows, macOS, Solaris, AIX, HP-UX | Free / Commercial |
Frequently Asked Questions
What is Security Onion?→
Security Onion is a Linux distribution that installs a complete network security monitoring stack, including Suricata and Zeek for network detection and metadata, Elastic for storage and search, and its own management interface for alerts, dashboards, and hunting. It also supports host telemetry such as Sysmon and osquery data, and it includes an intrusion detection honeypot (IDH) node option. Paid support, training, and the Security Onion Pro edition come through Security Onion Solutions.
What is Security Onion used for?→
Standing up full NSM capability on your own hardware without assembling the stack component by component.
What are the strengths of Security Onion?→
- +Curated suite of tools designed to work together instead of a parts list.
- +Same interface covers alerts, dashboards, PCAP, and hunt.
- +Scales from a single node to distributed grids.
What are the limitations of Security Onion?→
- +Hardware requirements are substantial for full packet capture.
- +The Elastic License 2.0 bars providing the software to third parties as a hosted or managed service.
How is Security Onion used defensively?→
Network and host telemetry collection with integrated detection for teams building their own SOC visibility.