The stopnps command kills the npsd process, which unloads the IPX protocol stack.
The stopnps command waits up to 60 seconds for IPX clone devices to be closed before proceeding. New requests to open /dev/ipx are disallowed until the stack is restarted.
To determine whether the stack is loaded, create a script using the statnps command and check the return value. If the stack is loaded, statnps returns a value of 0. If the stack is not loaded, statnps returns a value of 1.