NATO’s Counter Unmanned Aircraft Systems (C-UAS) Technical Interoperability Exercise 2021 (TIE21) was held from 2 to 12 November 2021 at the Lt.Gen. Best Barracks in Vredepeel, the Netherlands. More than 20 industry participants deployed around 70 systems during the exercise. Various radars, sensors, command and control systems, drones (UAS) and counter-drone equipment were shown. Some highlights were the demonstration of a counter UAS Jammer forcing a drone to land and a DroneCatcher counter drone system intercepting an illegal drone with a net!