One of the problems people face is that other people can't keep secrets. Yes, secrets! With my experience as a network engineer for one of the leading internet service providers in Nigeria, I have found out that one of the secrets that people often let out is wifi passwords. You give a colleague a wifi password on trust, he gives it to his crush who works in the same company on trust, and she in turn gives it to another of her colleagues who gives it to the driver who gives it to the chef who gives it to the security guard... It keeps going on and on until the company starts experiencing a very slow network.
So what do you do? Simple! You change the wifi password, and on it goes again. Now you will say
"what if i just log a few people who need internet on there system to work in without letting them know the password?" Just go to their systems and log them in. That way, they cant tell other people what the password is and can't connect their phones and tabs as well. That seems like a smart move until you see the image below.
Read more here: http://www.timigate.com/2016/11/how-to-configure-mac-filtering-on-your.html#more