All posts for the month October, 2013

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 ( ). Then go to the site

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.

AEtherchannel is the port link aggregation technology invented by a company named Kalpana. This company was acquired by Cisco systems in 1994.  Etherchannel allows us to group several ( practically eight ) physical Ethernet links on a Cisco switch into one logical link. Advantages of etherchannel include increased bandwidth and fault tolerance. For example, when we group eight physical ports into one logical port, considering bandwidth of each port is 100 Mbps, the combined bandwidth is 800 Mbps. What if one of the port fails?. Well the rest of the ports take over thus preventing any failure. Let’ see it a little bit practically.

Imagine we have a network as shown below. There are two separate departments named Sales and Engg  in a company which are connected through a router.



There comes a time when the traffic between these two significant departments becomes so intense that the network administrator decides to interconnect the two switches of the respective departments as shown below so that the traffice doesn’t disturb the router. ( CCNA guys, always remember that  switches are interconnected using crossover cables only ).



Considering the importance of the two departments, the network administrator decides not only to provide additional bandwidth but also provide fault tolerance between the departments. Etherchannel satisfies both these requirements.

Now let’s see how to configure etherchannel.  To configure etherchannel, login to SWITCH1. Enter global configuration mode by typing command “config t”. Type the command “interface port-channel 1″ to create etherchannel port trunk. Type command “interface range fastethernet 0/1-8″ to select eight interfaces to assign to our etherchannel port trunk. Type command “channel-group 1 mode on” to assign the interfaces to the etherchannel port trunk.



We can see below that we have successfully configured  etherchannel  on our switch.



Now let’s configure VLAN trunk over the etherchannel logical port trunk. Type command “interface port-channel 1″ to select the etherchannel port. Type command “switchport mode trunk” to  set etherchannel port as trunk port.



Hope this was helpful.

Good evening friends. We have seen how to create a virtual pentest lab both in Oracle VirtualBox (see here) and Vmware Workstation(see here). Although both penetration testing labs  were almost similar, there is a small difference between them . As the title of this howto already implies it is the absence of DHCP server in the pentest lab we created using Virtualbox. VirtualBox provides a DHCP server but it can’t be turned on using the GUI feature unlike Vmware Workstation. So let’s see how to enable DHCP server in Virtualbox networks. I am going to assign DHCP server to my pentest lab I created above. I will assume that  virtualbox is installed on Windows. Open CMD and navigate to the directory where  Virtualbox is installed. By default it will be “C:Program Files OracleVirtualBox”. Type the command “vboxmanage dhcpserver add –ip –netmask –lowerip –upperip –netname pentestlab”. Hit Enter.



In the above command, “vboxmanage dhcpserver  add –ip” starts a DHCP server with IP address . The “–netmask″ assigns subnet mask for the network. The “–lowerip” and “–upperip” options assign a lower ip address and upper ip address respectively.   The “–enable” option enables the DHCP server we just created. The “–netname” option assigns a name to the network. Now we have successfully created an internal network named pentestlab with its own DHCP server. Now change the network adapter settings of the attacker machine ( Kali Linux ) to pentestlab.



Similarly change the network settings of the victim machine.



Now start the attacker machine (Kali Linux) to see if the IP address is automatically assigned. If the IP address has not been assigned, disable the adapter using command “ifdown eth0″ and re enable it by typing command “ifup eth0″. Now check if the IP address has been assigned or not by typing command “ifconfig”.



Similarly check on the victim machine.



We can see that the IP addresses have been automatically assigned successfully starting from the range of Hope this was helpful.