Securing IoT devices is an ongoing problem. Typically username and passwords are the only method available to secure a device. Practically speaking these are rarely changed and are therefore exploited by denial of service bots.
One way to secure an IoT device in a robust and scalable manner is to put a firewall in front of each IoT device. Access to and from the IoT device can be controlled at a very granular level.
In one case we had a camera that out of the box would dial ‘home’ for instructions. By putting a simple firewall rule to block all access except to the video management system was a quick and practical solution to the problem.
Firewall rules can customized by type of IoT device. The network management tools allow managing these routers at scale.