Hi
I need an help about setting up an ACL on my RB2011 UAS-2HnD-IN. I want to forbidden explicitly all unknown devices to connect on my mikrotik by wireless interfaces.
Can someone help me about it please ?

Thank you

Replace 'wlan1' with the name of your wireless device if it is different. That is by terminal.
In winbox : Interfaces->Wireless->'your interface'-> Wireless tab->untick 'Default authenticate'

When you do that only the mac addresses added in access-list will be able to connect.

Thank you very much. It is working now.