IP address

All posts tagged IP address

Kali Linux is the most advanced penetration testing distribution with a number of tools. While using these tools a measure of anonymity is required. Today we are going to see how to spoof your IP address in Kali Linux. First, check your IP address by visiting any website which shows your IP address ( http://www.whatismyip.com ). Then go to the site www.vpnbook.com.

Download the Euro1 Server OpenVPN certificate bundle as shown below. Note down the username and password given. We will need it in later steps.



When you click on the download link, the following window opens. Since it is a zip package, system will prompt whether to open it with unzip ( the default option ). Click on “OK”.



Open the terminal and navigate to the directory where the cocntents of the zip archive have been unzipped. Type the command “ls” to see the unzipped files. We are going to use the vpnbook-euro1-udp53.ovpn package.



OpenVPN has been installed by default in the Kali Linux distribution. Type the command “openvpn vpnbook-euro1-udp53.ovpn” to start the process.



The installation starts.  Enter the username and password we noted above when prompted.



After a short time, the process is completed. Check your IP address again. If everything goes well, your IP address will be changed.

Good evening everybody. Sometime back, I wrote an article on how to set up a virtual penetration testing lab using Vmware Workstation. But Vmware Workstation is a commercial product.

Today I am going to show you how to create a pentest lab in VirtualBox absolutely free of cost. I hope this tutorial will be helpful for many beginners into cyber security domain.

What do we need?

1. Oracle VirtualBox. (Download)

2. Kali Linux. (Download)

3. Metasploitable 2. (Download)

Oracle VirtualBox is the virtualization software we will be using to create our lab. We will be using Kali Linux as the attacker machine and Metasploitable 2 as the victim machine. Install Kali Linux and Metasploitable 2 in VirtualBox.

See how to install Kali Linux in VirtualBox.

See how to install Metasploitable in VirtualBox.



Select Kali Linux, Go to settings > network. Enable “network adapter 1″. Set the “Attached to” option to “internal network”. Set the name of the network adapter to “intnet”. Click on “OK” to save the settings.



Do the same for Metasploitable virtual machine.



Power on the metasploitable VM. Log into the system. Default username and password are “msfadmin”.



Type the command “ifconfig” to see the IP addresses of interfaces.



The ‘lo’ interface is the loopback. Now we are going to set the IP address on the interface “eth0”. Type the command “sudo ifconfig eth0 netmask up”. The sudo password is “msfadmin. Verify that the IP address is set by typing command “ifconfig”.



Power on Kali Linux. In the terminal, type command “ifconfig eth0 netmask up”. Verify if the IP address is set by typing command “ifconfig”.



Test whether this system can communicate with victim system by pinging the victim machine as shown below.



The connection is successful. Our penetration testing lab is ready. Happy practising.

Understanding subnetting is very important not only for those preparing for CCNA exam but also network administrators. Today, I am going to teach you how to create a subnet in a network. For this, I will use Packet Tracer software. To know what is subnetting and why we need it go here. So let’s start.

Imagine I formed a small software company named shunya whose network looks like below. I hired one Java developer, one software tester, one HR and one network administrator. I have been assigned the IP address range from to



I have enabled DHCP on my router as below.




After one year, imagine my company has received Abrahamic blessings from GOD and has seen rapid growth. Now the company has three Java developers, three software testers and  a dedicated HR team. Not only that, my company now has moved into Remote Infrastructure Management(RIM) and has a Network Operation Center(NOC) and Security Operation Center(SOC).  Total I have 15 computers in my network which looks like below.



Now see the image below. Here the machine “JD1″ sends a packet to machine “Testing3″. We can see here that for communication between machines “JD1: and “Testing3″ other machines have also been disturbed.



So for this reason, I decided to subnet the network. I decide to divide the network into three subnets as shown below.



To create a subnet, first we need to have proper planning as to how many subnets we need and how many we may need in the future. Presently, I need three subnets. The number of subnets should always be calcutated in the powers of 2.

2 to the power of 1 = 2

This doesn’t satisfy our requirement as we need three subnets.

2 to the power of 2 = 4

This satisfies our requirement. So we need to take two bits from the host portion of the IP address. to is the address range available to us with subnet mask,  Writing the subnet mask in the binary notation, it is

11111111 11111111 11111111 00000000

 255            255          255             0  

The first 24 bits are network bits and the last eight bits are host bits. To create three subnets, we need to take two bits from the host portion of the address as explained above.

11111111 111111111 11111111 11000000

   255              255            255         192

Four subnets which can be created from the above subnet mask are, to ( with host bits 00000000 ) to ( with host bits 01000000 ) to ( with host bits 10000000 ) to ( with host bits 11000000 )

Since we require only three subnets, we will create the first three subnets. The first subnet ( to ) comprises of Java Developers and Software testers. The commands are as below on the interface.



If you go to any machine on this subnet and look at its IP address, it will be like below.


Now the subnet for the Human Resource Department ( to ) . This will be like below.






The third subnet ( to ) comprises of NOC and SOC.







Now our network has been successfully subnetted into three subnets and we still have another subnet to use for future use.




Hope this was helpful. If you have any doubts regarding this article please comment below. Thank you.


I am self learning for CCNA. A few months back, I got a thought if we can simulate routers in Vmware Workstation. While I was searching for it I found a different solution, GNS3. After simulating routers in GNS3 and practising CLI interface, I had another idea if we can simulate CISCO Graphical User Interface on our PC. This article is  result of that.

In this article, we are not only going to see how to connect Vmware and GNS3 but also see how to simulate CISCO Graphical user Interface (GUI). For this I use,

1. Vmware Workstation 9.

2. Windows XP as Guest OS.

3. Cisco Security Device Manager v25.

4. GNS3.

5.  C7200 Router Image.

Open Vmware Workstation. On the menu Select “Edit>Virtual Network Editor”. On the Virtal network editor, click on “Vmnet1″ network. It is a default Host-only type network adapter of Vmware. Observe its settings. Enable DHCP server.



Install Windows XP as a guest. On its virtual machine settings, change the network adapter to “Vmnet1″.



Power on the machine. Install Cisco SDM ( I leave the getting Cisco SDM part to you ). Open CMD and type “ipconfig” to see its IP address. Take note of this.


Open GNS3. Click on “Browse all devices”.



Select Router “c7200″ and drag it to the workspace. Do the same with “Cloud”.



Close the All Devices tab. Right click on the Cloud.  Select “Configure”, a ‘node configurator’ window will open. On this window, click on “C1″.


On the NIO Ethernet tab, in the “Generic Ethernet NIO tab” dropdown menu, select our network adapter (Vmnet1) from the dropdown menu and click on “Add”. Click on “OK” to close the window.


Right click on the router. Select “Configure”, click on “R1″. Select slots tab. In the Slot 1 dropdown menu, select “PA-4E”. Click on Apply an close the window. The selection PA-4E creates four Ethernet ports on the router. Right click on the router and start the router.


Add a link from “cloud( Vmnet1)” adapter to the “e1/0″ port on the router.


Hover your mouse over the router. We can see all the ports.


Similarly hover your mouse over the cloud to see its connections.



Right click on the router and select “Console”. In the global configuration mode, type the following commands.

ip http server”

ip http secure-server”

These commands set up http and https servers respectively which are needed for Cisco SDM.


Type the command “interface Ethernet 1/0″. We are entering into specific configuration mode of our connected interface. Type the command “ip address″. This sets the interface IP address and subnet mask. Make sure the router IP address is in the same subnet as that of our guest OS in Vmware workstation. Type “no shut” and exit to the privileged mode.


Let’s ping our guest from the router. to ensure that we are connected to Vmware Guest.


Since success rate is 100%  we have successfully connected Vmware and GNS3. Now let’s do the Cisco SDM part. On our Guest machine click on Cisco SDM. A SDM launcher window will open. Type the IP address of the router and click on Launch.



Internet Explorer will open as below. Make sure Internet Explorer is configured to allow pop ups and to allow Activex to run from the computer.



After some time the following popup will open. Don’t close it.



Then we might see a certificate warning. Click on Yes.



After some processing, Cisco SDM will open.



We have successfully simulated Cisco GUI on our PC. Happy practice friends.

Virtual penetration testing lab is a lab created on a single system using any virtualization software. It can be very helpful for people practising for CEH or similar certification. Any penetration testing lab has two machines, attacker and victim. In this lab we will set up Kali Linux as the attacker and Windows XP( most favourite victim machine ) as the victim. I am going to set up this lab in Vmware Workstation 9. Hope this will be helpful.

First of all install Kali Linux and Windows XP in Vmware Workstation.




Shut them down. In the Vmware Workstation menu, Select Edit” and click on Virtual Network editor.


The window below will open showing the virtual network adapters. Click on “Add network”.


Vmware provides nine virtual networks from 0 to 9. Vmnet0, Vmnet1 and Vmnet8 are automatically assigned for  bridged, Host-only and NAT types of network respectively. Select the network “Vmnet3″.


We can see that our network is added as Host-Type with a automatically assigned subnet IP.



Click on our network. We can see its settings below.



Deselect the option ‘Connect a host virtual adapter to the network‘.This will make our network a custom type. Change the subnet IP to choice is yours).  Select the ‘Use local DHCP service to distribute IP address to VMs‘ option. This will automatically assign IP addresses to our machines. Click on ‘DHCP settings‘.


You will see the below window. Make changes if you like. I am going to leave it default. Click OK twice to exit.



We have successfully created our custom network. Now let’s add our machines to the network. Open the tab of Kali Linux and click on ‘network adapter‘ setting.


In the settings, select the ‘custom radio button and select the network Vmnet3 from the dropdown menu. Click on OK.


Do the same for Windows XP. Then let’s boot up our victim machine and check it’s IP address by typing ‘ipconfig‘ in the command line.The DHCP server has automatically assigned it the IP address



Boot the attacker machine and check it’s ip address by typing ‘ifconfig’ in the terminal. It has been assigned the address


Ping the victim IP machine ( to see whether the two machines can communicate.



We have successfully created a virtual penetration testing lab. Happy testing.

In this article, we are going to see how to set up a web server in Ubuntu Server. Before that, I want to give  credit for this article to Mike of www.funwithlinux.net. I learnt how to install the web server from this article, made some mistakes initially but finally successful.

What is a web server? It is a server which hosts websites. Each and every website has a  server. Most web servers are set up on Linux for the primary reason that it is free. I am going to set up my web server on Ubuntu Server 12.04.

To set up a web server we are going to install four components, Apache (server software), PHP (scripting language used to create webpages), MYSQL (database), PHP-MYSQL (MySQL support in PHP ). Login as root into Ubuntu server.

In the terminal type “apt-get install apache2″ to install Apache package. Type ‘Y’ when system prompts you to continue.



To check whether apache packages have been installed or not type the command “wget localhost index.html” in the terminal. This will download the index.html file to the local directory. Type “ls” to see if the file has been downloaded or not. If it is present, apache has been correctly installed.


The apache2 config file is located at “/etc/apache2/”. In this same directory we have a directory named ‘conf.d’. Configuration files( files with the suffix .conf ) in this directory will be parsed by apache2 during startup.  If we intend to run multiple sites from the same server, we need to put our config files here. Let’s create a file name “shunya.com.conf”.


In the file shunya.com.conf, add the following text and save the file. The first line tells  Apache to  listen on port 80. The second line shows the ServerAdmin and is optional. The third line shows our web server’s root directory. The fourth line is host header Apache2 will listen for, as sent by the end user’s browser. The fifith line is the file used for logging errors. This line is also optional but is very helpful.  The settings not configured under <VirtualHost> tags will be inherted from apache2.conf or other configuration files. Close the file by typing “:wq”.



As we created the config file of our host, we need to create our root directory referenced in the config file i.e “/var/www/shunya.com”. Navigate to the directory by typing “cd /var/www/”. Create new direcory named ‘shunya.com’ by typing “mkdir shunya.com”. Make the root user the owner of the directory by typing the command “chown root:www-data /var/www/shunya.com -R”. Make this directory readable and executable by typing the command “chmod 550 /var/www/shunya.com -R”.



Create a file named index.php in our root directory shunya.com.



Edit the file as below. We will echo some Archimedes in our index.php file. Save and exit the file.



Next, we have to install PHP. Type the command “apt-get install php5″. Type Y at appropriate prompts.



Reload the apache config file by typing “service apache2 reload”. Then restart the apache service using “service apache2 restart”.



Let’s see if our website is working. From a remote machine which has access to ur web server open the browser and type the IP address of the web server. If we get “Eureka Eureka” displayed, then our server is working.



Install Mysql server by typing “apt-get install mysql-server”. 



The system will prompt you to set a root user password for MYSQL. Set the password and confirm it again.




Type the command “apt-get install php5-mysql” to install Mysql support for PHP.



We have set up our web server successfully.

Nmap is a popular port scanner. Today we are going to see target specification in nmap. In Nmap target can be specified in six different ways. We are going to look at each one of them. For this, I am using Kali Linux connected internally with IP address

1. nmap -iL <input filename>

This option reads targets from a specific file. Let’s create a file named alpha with a few   newline separated or tab-limited or space separated IP addresses using vi on Desktop.



Then, move to Desktop directory and type the command “nmap -iL alpha” as shown below. It scans the four IP addresses listed in our file.


2. nmap -iR <number of hosts>

This option is used to specify random hosts to scan. Nmap generates its own targets to scan. The <number of hosts> argument tells nmap the number of IP’s to generate. Let’s type command “nmap -iR 5″. We can see that nmap generated five random targets to scan. The scan failed to determine route to the generated IP addresses because my system is not connected to Internet. Why didn’t it generate any internal IP addresses? Because in this scan private, multicast and unallocated address ranges are automatically skipped.



3. nmap <IP address/dir>

This option is used to scan the entire subnet.  Assuming you know CIDR let’s type the command nmap to scan eight IP addresses from to and see the result below.



4. nmap [targets] -exclude[targets]

This option specifies a comma separated list of targets to be excluded from the scan even if they are part of overall network range we specify. For example, in our previous scan we saw that one host which is the system I am working on) is alive. Now I decided to exclude that host and another host from the scan. So I type the command “nmap -exclude,″ and press “Enter”. We can see that nmap has only scanned six IP addresses.



5. nmap [targets] -excludefile[file name]

Now what if the subnet was very big and there are more number of hosts to be excluded from the scan. The above option helps us to achieve this. Remember the file “alpha”( with four IP addresses) we created. Now let’s specify nmap to quit scanning the hosts listed in the file. Type command “nmap -excludefile alpha”. We can see that nmap scanned only four hosts in the subnet.



6. nmap [target1 target2  target3]

This option specfies nmap to scan multiple targets separated by space. Type the command  “nmap″. We can see the result below.



Hope this was helpful.

Hi everybody, today I’m gonna show you remote password cracking with Brutus. For the newbies, script kiddie is a person with little knowledge  of hacking or any programming languages and instead searches for automatic tools to hack the computers. In this scenario, script kiddie is using a Windows XP machine and two tools Zenmap and Brutus avilable for free to download. As you will see, Zenmap is used for scanning for any open ports of  live machines and Brutus is a password cracker.

Imagine I am the script kiddie, I  first find out my own computer’s  ip address by typing the command “ipconfig” in the command line.

The ip address of my system happens to be I decide to scan the following range of ip addresses to look for any live hosts. In the target option, I specify ip address as and I choose profile as intense scan to get maximum information about the target. After performing the scan, the results show that only one system is alive.

The scan  also shows that the victim machine which is live  is running a ftp server and its operating system is Windows XP.

I decide to use Brutus to crack the remote FTP password. Brutus has both dictionary and bruteforce attack options. I decide to choose dictionary attack since it is faster than bruteforcing. Brutus comes with a built in username(users.txt) and password list(pass.txt).As the victim machine is running Windows xp which comes with a default administrator account, I decide to  add “administrator” to the users.txt file.

I choose type as FTP since I am about  to crack a FTP server.

Then I select the file pass.txt containing some common passwords and just hope to crack the password.

Then after starting the cracker, Brutus runs and gives one positive authentication result.

Username : administrator

Password: 123456

Then I try to log into the FTP server of the remote machine using cmd with the authentication result achieved above.

I successfully logged into the FTP server.Once I am into the remote machine I try some ftp commands but before that I change my local directory to Desktop.

Then I use DIR command to list the directories in the FTP server.

There are four directories in the FTP server:Detroit,Images,lena and users. I  go to the users directory using command cd users and then list the files in the directory by using command ls. There is one text file named users.txt in the directory.

I decide to download the file users.txt to my machine using the command get users.txt. Since I had set my local directory to desktop it will be downloaded to desktop.

Let’s see the contents of the users.txt file just downloaded. It contains some usernames and passwords.

In the same way, I enter into another directory of interest to me “Images” and download the only image present in it to my desktop.

In this way, I can download any number of files from the remote server to my local machine. That’s all for now.