genuwall is an industrial firewall appliance designed for securing production networks (LAN, WAN, and VLAN) in operational technology (OT) environments. It enforces network segmentation by creating security zones for individual machines, entire systems, or production areas, controlling all data traffic and permitting only authorized connections. The product operates beyond standard routing by supporting a Bridging Mode, allowing it to function as a stealth system without requiring IP address changes — enabling integration into existing networks without reconfiguration. It filters traffic at the application layer, with specific support for industrial protocols including OPC UA, Modbus TCP, and IEC 60870-5-104, detecting and discarding invalid or unauthorized data packets. genuwall is built on a product core derived from the classified (Geheimschutz) security domain and has been audited by the German Federal Office for Information Security (BSI). Its update mechanism is designed to be resistant to quantum computing-based attacks. The appliance supports throughput of up to 2 Gbit/s and can be deployed either in standalone mode or managed centrally. Initial installation and reinstallation are facilitated via USB boot. The product provides logging, reporting, and monitoring capabilities to ensure traceability of changes and access events. Use cases include OT network segmentation, defense against industrial espionage, reduction of downtime risk from external interference, and compliance with recommendations from industry associations such as the VDMA (German Mechanical Engineering Industry Association).