Bypassing MAC filtering:-
As already said, it is very easy to bypass MAC filtering as MAC filters are displayed in plain text in all WLAN headers. So we can just sniff the air and find out the MAC address of any legitimate user and then impersonate that user. If you have learned till now, then it must be very easy for you to sniff packets through wire-shark and also through airodump-ng.
So to bypass mac filter just start sniffing the air with wire-shark or Airodump-ng and find out the MAC address of a legitimate client connected to that network.
Then using aireplay-ng we can impersonate that user. Aireplay-ng has a option for fake authentication. The command to use to impersonate a MAC address would be
aireplay-ng --fakeauth 10 -e ESSID -h 0f:12:ff:2f:6d:32 mon0
Now what each parameter in this command does is an exercise for to find out. It is pretty easy though and is apparent from the command itself We will now see that we have successfully authenticated with the client with that AP.