Yes, it does. So, for now we’ve confirmed that the agent at least does what it’s supposed to do. Next thing is to see what arrives at your CheckMK server. So from the CheckMK server try something like this:
nc -v <client IP> 6556
Then check the output. If the df data is in there, then try something like this as the site user:
cmk -d <clientname>
Where <clientname> is the name of your client as it’s know in CheckMK. Again see if the df output is shown.