There is no option to blacklist a client from the GUI.
We can do it from the command line of AMP using the on_controllers directive combined with the "stm add-blacklist-client" directive:
Login as ROOT to the cli of Airwave box and run the below commands.
# on_controllers "stm add-blacklist-client <mac address>"
AMP will login to all the controllers which are being monitored by Airwave and add that client to the blacklist.
We can also see what clients are blacklisted on each controller by running;
# on_controllers "show ap blacklist-clients"