Hardware Data Diodes for 1G Fiber Networks

A common visibility use case in OT networks is to route mirrored traffic from a SPAN port on an industrial switch to a security or monitoring sensor. Port mirroring, also known as SPAN (Switch Port Analyzer), is a designated port on a network switch that is programmed to mirror, or send a copy, of network packets seen on a specific port, where the packets can be analyzed.

In critical network deployments like OT environments, if using SPAN is the only option to connect security sensors then additional security measures should be taken. It is best practice to connect the SPAN/Mirror port to a hardware Data Diode to pass the mirrored data onto the monitoring and security sensors. Using hardware Data Diodes eliminate bidirectional traffic flow ensuring that no data is passed back into the Switch Mirror port. Hardware Data Diodes are purpose-built network devices that enforce one-way data flow for Switch Mirror ports with physical hardware separation.

They guarantee protection of critical systems, such as industrial control systems (ICS), from inbound cyber threats. Garland Technology’s Hardware Data Diodes ensure any ethernet packet flows in one direction out the monitoring ports.