OTDefend vs Tenable One OT Exposure

OTDefend provides passive monitoring, threat detection, vulnerability management, and response for industrial environments. Its network intrusion detection inspects more than 16 industrial protocols from a mirror or TAP port, and the maker says it does not inject traffic. Supported protocols include Modbus, S7comm, DNP3, EtherNet/IP, IEC-104, IEC 61850, PROFINET, EtherCAT, POWERLINK, CC-Link IE, OPC UA, BACnet, FINS, MELSEC, and HART-IP. A dependency-free Windows agent runs from Windows XP through Windows 11 and collects host inventory and intrusion-detection events. Detection combines network IDS signatures, Sigma analytics, and YARA signatures; the homepage states 688 rules. A built-in threat-intelligence store accepts TAXII 2.1 and STIX 2.1 feeds and checks indicators against live traffic. Deployment options include an offline Docker bundle, a .deb sensor, and a bootable appliance ISO. OTDefend lists SIEM and other security integrations, plus IEC 62443, NERC CIP, and NIS2 reporting with exportable PDFs. Its design includes per-tenant isolation, role-based access, an active/standby core, and one-way sensors for data-diode segments. Pricing is on request.

Tenable One OT Exposure is web-based software for operational technology security. It provides passive monitoring and OT asset discovery, giving organizations visibility into network activity and connected OT assets. Supported protocols are Modbus, Modbus UMAS, Modbus MODICON, CIP, PROFINET, DNP3, IEC 60870-5-104, MMS, S7/S7+, and IEC 61850. The product also supports SIEM integration for connecting OT observations with security-information workflows. Tenable lists two purchasing routes: a standalone subscription and a perpetual license with maintenance. Both require one license for each detected IP address, while prices are available on request. The software is available through the web. Tenable was founded in 2002 and is headquartered in Columbia, Maryland, United States. The central operating model is passive observation rather than active scanning, paired with discovery of OT devices and protocol-aware visibility. Organizations considering it need to account for licensing tied to detected IP addresses when estimating deployment scope and discussing either the subscription or perpetual-maintenance option with Tenable.