How to change ROOT password in Linux

Enter the command passwd.

Then choose the password you want!

Installing Aircrack-NG on Linux

Aircrack-ng is an 802.11 WEP and WPA-PSK keys cracking program that can recover keys once enough data packets have been captured. Fir installation, run the following commands :

sudo apt-get install build-essential

sudo apt-get install libssl-dev

wget http://download.aircrack-ng.org/aircrack-ng-1.1.tar.gz

tar -zxvf aircrack-ng-1.1.tar.gz

cd aircrack-ng-1.1

Edit the file common.mak before you run make and make install.

sudo gedit common.mak

Locate and change the unused variable werror. Change :

CFLAGS          ?= -g -W -Wall -Werror -O3

to

CFLAGS          ?= -g -W -Wall -O3

Now run :

sudo make
sudo make install 

After the installation, if you get a prompt as follows :

[*] Run 'airodump-ng-oui-update' as root (or with sudo) to install 
or update Airodump-ng OUI file (Internet connection required). 

Then run the command :

sudo airodump-ng-oui-update

Installing ettercap on Linux

Ettercap is a comprehensive suite for man in the middle attacks. It features sniffing of live connections, content filtering on the fly and many other interesting tricks. It supports active and passive dissection of many protocols and includes many features for network and host analysis.

For installing ettercap, use the following commands :

sudo apt-get install zlib1g zlib1g-dev
sudo apt-get install build-essential
sudo apt-get install ettercap

You will be prompted to choose between ettercap text-only and ettercap-graphical packages. Choose accordingly.

 

For installing ettercap-graphical, use the command :

sudo apt-get install ettercap-graphical

For installing ettercap-text only, use the command :

sudo apt-get install ettercap-text-only

 

After the installation is done, you can open ettercap in different modes. For opening ettercap in graphic mode, use :

sudo ettercap -G

For text mode, use

sudo ettercap -T

To read about ettercap and its different modes, you can use :

man ettercap

Note : 'man' is short for manual. It can be used to read about all commands (description, syntax etc.)

Capturing Packets using Wireshark

To start the capture of packets, select the interface from the left panel and click on Start.

Once you click on start, you'll notice that the capture of packets has begun and all the packets to and from your computer starts appearing.

 

If you just want to see a paticular type of packets, say ARP, HTTP etc., you can also add a filter. In the top left corner, type the desired type of packet. Only that type of packet will appear.

Installing Wireshark

Wireshark is a network protocol analyzer. If you are networking geek, its a software you would definitely have on your system. Whether you are looking at network troubleshooting, analysis, software and communications protocol development or just as a hobby, Wireshark is your go-to tool.
To install on Windows, you download the latest release from here. Each Windows package comes with the latest stable release of WinPcap, which is required for live packet capture. If needed you can install the latest development release from here.
To install on a Linux system, you can run the command :

yum install wireshark (Fedora/CentOS)

sudo apt-get install wireshark (Debian/Ubuntu)

After the installation, to run Wireshark, type wireshark in the terminal.