Until recently, most operational technology (OT) processes ran on isolated networks with specific protocols. This tended to make security a simple matter of physical protection. The separation of the OT network from everything else—the so-called air gap—made it easy to ignore the major cybersecurity headaches being faced in data centers and business networks. This paper will discuss the impact of IIoT and 5G on security for a modern OT environment. It will also review the architectural considerations for providing secure connectivity in the enterprise and demonstrate how modern techniques can support both the security and flexibility required in today’s enterprise.