The exam container goes offline at the host kernel

9:00 AM, forty students, one practical exam. Each student has a container cloned from the exam image: compiler, test data, starter files. Ten minutes before the start, a script adds three egress rules to every container: drop tcp, drop udp, drop icmp4, destination 0.0.0.0/0.

The rules run on the host kernel, outside the container. A student with root inside their box still can't reach Stack Overflow, a chat model, or a friend's machine. They can't edit the rules either; the firewall isn't theirs. Their terminal URL still works, because it arrives through the proxy, not through the container's outbound path.

At 11:00 the same script flips enable_proxy to false on all forty. Pencils down is a 403.

No lockdown browser, no proctoring software, no kiosk mode. The proctor is the kernel, and the kernel doesn't take bribes.

The proctor is the kernel, and the kernel doesn't take bribes.