This read-only Integer32 reports the IOCTL number of the last configuration change made on this device. Admins use it alongside lastCfgChgInitiator to identify, at a low level, what kind of change command was last applied to the device's configuration, useful for change auditing. For example, correlating a specific lastCfgChgCmd value with the vendor's IOCTL reference can tell an admin exactly what type of configuration operation (such as a policy update) was last performed.