From itproportal.com
![infrastructure](https://cdn.mos.cms.futurecdn.net/z7vW83VFvFds3XA4JKjvM9-320-80.jpg)
Around the world, critical national infrastructure (CNI) such as transport, energy and essential manufacturing is run on legacy networks. Unlike the fast-moving realm of modern IT environments, the operational technology (OT) underpinning these systems was built to last, with a lifespan usually measured in decades. As a consequence, many of the systems being relied on for CNI have been in use for more than 25 years.