Networking

Articles about networking.

Matriux Krypton is a pen testing distribution based on Debian. It consists of almost 300 security tools for ethical hacking categorized as arsenals. It has a category for data recovery which is not prevalent in other penetration testing distros. Today we are going to see how to install Matriux Krypton Ec-Centric in Oracle Virtual box. It can be downloaded from here. Open Virtualbox and click on “New virtual machine”. On the popup window, give the name as Matriux ( in fact any name you like ). Select operating system as “Linux” and version as “Ubuntu”. Click on “Next”.

matriux1

 

Select the appropriate memory you want to assign to the virtual machine and click on “Next”.

matriux2

 

Select the option “create a virtual hard drive file” and click on “Create”.

matriux3

 

Select Hard drive file type as VDI. Click on “Next”.

matriux4

 

Choose appropriate storage option and click on “Next”.

matriux5

 

Set your virtual hard disk size appropriately but I suggest you to keep it above 8 GB. Click on “Create”.

matriux6

 

Select the location of the iso file and click on “Start”.

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Select the option “Live”  and hit Enter.

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Log into account matriux. The default password is  “toor“.

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 If everything went well, your system should look like this.

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 Before running the Matriux disk Installer, we need to perform some operations. Go to “System>Administration>Gparted” as shown below.

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 Enter the administrative password as “toor”. Click on “OK”.

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 In the gparted window, click on “Create Partition table”.

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 When a warning is shown, click on “Apply”.

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 Right click on the unallocated hard disk and select “New” as shown below.

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 Change the file system  to ext3 and click on “Add”.

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We can see our “New Partition” ready to be created. Click on the “tick mark with blue background”.

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 We can see our partition created as below.

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 Close the window and click on “Matriux Disk Installer” we saw above. When the window opens as below, click on “Yes”.

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 Choose the partition we created( i.e /dev/sda1) and click on “OK”.

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Click on “OK”.

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Click on “OK”.

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Create a personal account login name.

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Choose the password for you personal account. Click on “OK”.

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Choose the root account password. Click on “OK”.

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Select the appropriate locale as en_US. Click on “OK”.

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If everything goes well, we will get a window as shown below. Click on “Yes”.

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 We will get the below message after successful installation.  Click on “Yes” to reboot your system and you are ready to go.

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Hope this was helpful.

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.

etherchannel1

 

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 ).

etherchannel2

 

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.

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

etherchannel4

 

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.

etherchannel5

 

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 10.10.10.1 –netmask 255.0.0.0 –lowerip 10.10.10.2 –upperip 10.10.10.10 –netname pentestlab”. Hit Enter.

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In the above command, “vboxmanage dhcpserver  add –ip 10.10.10.1” starts a DHCP server with IP address 10.10.10.1 . The “–netmask 255.0.0.0″ 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.

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Similarly change the network settings of the victim machine.

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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”.

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Similarly check on the victim machine.

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We can see that the IP addresses have been automatically assigned successfully starting from the range of 10.10.10.2. Hope this was helpful.

According to Wikipedia, “In computer networking, a single layer-2 network may be partitioned to create multiple distinct broadcast domains, which are mutually isolated so that packets can only pass between them via one or more routers; such a domain is referred to as a Virtual Local Area NetworkVirtual LAN or VLAN.”

VLAN’s simplify network management, limit the size of a broadcast domain and improve network efficiency. VLANs are of two types.

  • Static VLAN
  • Dynamic VLAN

In a static VLAN, we assign specific ports to a specific VLAN. whereas in dynamic VLAN we assign MAC addresses to a specific VLAN. In this article we are going to see how to create and configure a static VLAN. We are going to create three VLANs and assign ports to them. For this example, we will create three VLANs named Java, SAP and HR.

vlan1

 

We need to be in global configuration mode to create VLANs. The command “vlan 2″ assigns number 2 to the VLAN we are going to create. We can assign any number from 2 to 4094 to the vlan. The command “name java” names our vlan as java. Similarly we can create the vlans SAP and HR.  Before assigning ports to the VLAN let’s see the port states in our switch.

vlan2

 

We can see above that all the ports of the switch are members of VLAN 1. VLAN 1 is a special purpose VLAN used for administration. It is the only precreated VLAN on the Cisco switch. All ports are members of this VLAN by default. So when you are assigning a port to a specific VLAN, you are just changing the port from VLAN1 to that VLAN.

Now let’s assign ports to the VLANs we just created. First,  let’s assign three ports to the VLAN java.

vlan3

 

The “interface fastethernet 0/1″ command selects the fastethernet port 1. The “switchport access vlan2″ command assigns this port to VLAN java. Similarly we can add the fastethernet ports 2 and 3 to the vlan 2. Now let’s see the port states once again.

vlan4

 

We can see that the first three fastethernet ports have been assigned to the VLAN java. Now we will assign fastethernet ports 4 and 5 to VLANs SAP and HR respectively.

vlan5

 

This is how our network  will look like if we connect the host devices.

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And our port states will look like this.

vlan7

 

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.

pentestlab1

 

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.

pentestlab2

 

Do the same for Metasploitable virtual machine.

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

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

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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 10.10.10.2 netmask 255.0.0.0 up”. The sudo password is “msfadmin. Verify that the IP address is set by typing command “ifconfig”.

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Power on Kali Linux. In the terminal, type command “ifconfig eth0 10.10.10.1 netmask 255.0.0.0 up”. Verify if the IP address is set by typing command “ifconfig”.

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

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


Today I’m gonna show you how to install metasploitable in VirtualBox. Metasploitable is a Linux virtual machine made vulnerable intentionally for testing purposes. This virtual machine can be used to conduct security training, test security tools, and practice common penetration testing techniques.  For this i am going to use Metasploitable 2 which can be downloaded from here. After downloading the zip archive, extract the files into a folder. The file contents look like below.

metasploitable1

Open VirtualBox and click on “New Virtual machine wizard”. Type the name of your choice. I am using ‘Metasploitable-2‘. Choose ‘Type’ as Linux and ‘version’ as Ubuntu. Click on “Next”.

metasploitable2

Choose the memory size appropriate to the availability of RAM on your host machine although 512MB is more than enough. Click on “Next”.

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In the hard drive creation window, select option “Use an existing virtual hard drive”, browse to the folder where we have extracted our zip files and select the ‘vmdk’ file available. Click on “Create”.

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Then you are automatically booted into the metasploitable OS. The default username and password are “msfadmin”.

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NOTE : Kali Linux version 2017.1 has been released and I decided to update this howto. Ofcourse,  this guide also works with previous releases of Kali Linux. 

Hi Friends. as you already know, the latest version of Kali, Kali rolling edition 2017.1 has been released. The rolling edition of Kali Linux gives users the best of all worlds – the stability of Debian, together with the latest versions of the many outstanding penetration testing tools created and shared by the information security community. The best feature I like in this version is constantly updated tools. Now let us see how to install this latest version of Kali linux in virtualbox and I assure you, this will be the easiest guide.

For this howto, I am using the latest version of Oracle Virtualbox, i.e version 5.1.22. Ever since Sana has been released, the makers of Kali Linux have also released Pre-built virtual images for virtualbox and Vmware. We will use that virtualbox image in this howto. Go here and download the Pre-built virtualbox image. They are as shown below (Download the latest version).

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This howto is using the Kali Linux 32bit VBox PAE . Your downloaded contents should look like below. As you can see, we have an ova file.

 

Now open Virtualbox and click on File>Import Appliance as shown below.

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A window like below will open.

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Now browse to the location of the ova file we just downloaded as shown below and  click on Next.

 

The system will present you a summary of settings used for  thsi VM. If you want to make any changes, change and click on Import.

The importing process will start as shown below. It will take some time, but it will be worth the wait.

 

After import is completed, a new virtual machine is automatically created as shown below.

 

Power on the machine. As the virtual machine powers up, it will prompt for username and password. The default username is “root” and password is “toor”.

Given below is our Kali Linux rolling 2017.1 successfully installed in Virtualbox. No need of installing guest additions. If you face any problems during installation, please comment. I will be happy to help you.

sanarvb12

 

 

 

Imagine you are a network administrator in a large organization with number of switches and routers. To configure a switch or router on a far off location, there are two choices. One is to go near the switch or router to configure it. This is good but imagine how much trouble it is  to go near each and every device to configure it. The second and easy option is the remote configuration of the switch or router.

Remote configuration of a switch/router can be done using telnet or ssh protocols. But using telnet has a disadvantage. It sends data in plain text. So if you happen to type a username ad password for authentication with the switch from a remote location, it will be passed in plain text and anyone sniffing on the network can easily find out your login credentials. This is a big security risk. To overcome this problem, we should use ssh protocol for remote configuration of the switch or router.  SSH protocol is as same as telnet but it uses encryption during the communication. This makes it difficult for hackers to detect the credentials. Let’s see how to enable ssh on cisco routers and switches using IOS. Here I am using a router.

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The command “conf t” enables global configuration mode of the switch or router. The “hostname R1″ command changes the default name of router to R1. The name of the router is used to generate names for the keys  by the ssh protocol. So it is necessary to change the default name of the router. The “ip domain-name shunya.com” command sets the domain name for the router. The domain name is also needed for setting name for encryption keys. ( Shunya.com is a fictional domain name I used. you can use your own domain name ).  It’s  time to set login credentials on the router. The “username admin password 123456″ command sets the username and password to admin and 123456 respectively. The “line vty 0 15″ command selects the vty lines from 0 to 15 for line configuration. The “login local” command sets the login to local router. The “exit” command takes us out of the line configuration mode to global configuration mode. it’s time to generate ssh keys.

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The “crypto key generate rsa” command generates the cryptographic keys using Rivest Shamir Adlemann algorithm. You will be prompted to enter the number of bits in the modulus. Setting it too low will be too easy to crack. Setting it too high will be time consuming. I set it to 1024.

Let’s see the information about ssh protocol we enabled on the router.

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The “show ip ssh” command does this. The reason for prepending this command with “do” is that the “show ip ssh”  is a privileged exec mode command and cannot be executed in global configuration mode. We can also see from the information displayed that the authentication timeout has been set to 120 secs and authentication retries are set to three. Let’s change them. The command “ip ssh time-out 60″ command changes authentication time-out  to 60 secs.  The command “ip ssh authentication-retries” command is used to change the authentication retries.

Finally we will have to set ssh as input transport protocol on vty access lines.

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The “line vty 0 15″ command selects all the vty lines. The “transport input ssh” command sets ssh as a input transport protocol.  The “exit” command as already said takes us out of the line configuration mode. We have successfully enabled ssh protocol on our router.

Let’s once again see the information about the ssh we just enabled using “do show ip ssh”.

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We have seen how to set passwords on cisco switches or routers here. Of course setting passwords does add to the security of the device but there is small problem. The password is stored in plain text.  Anyone who gets access to the switch can easily see all the passwords by typing command “show running-config or show startup-config”. Today we will see how to encrypt passwords on Cisco routers and switches.

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Encrypting passwords can further enhance the security of the device. Privileged password can be encrypted by using the command “enable secret” instead of “enable password”. This command should be set from privileged global configuration mode.

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Lets see what can we see  when we use the command “show running-config”.

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We can see that the password we set has been encrypted. but what about other passwords. The  console, auxiliary and vty lines passwords cannot be encrypted even if we use “enable secret” command. To encrypt those passwords, we have to use another command “service password-encryption” as shown below.

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This command will encrypt all the passwords stored in plain text on the device.

Good evening friends, Today we will see how to configure passwords on Cisco routers and switches. Cisco devices have four types of passwords.

  • Console password : Used to set password for the console access.
  • Auxiliary password : It is used to set password to auxiliary port ( if the switch has one.)
  • VTY lines password : Used to set password for  for telnet and ssh access.
  • Privileged password : Used to set password for privileged access to the switch.

I am not going to show you how to set up auxiliary password here. To see how to set up console password and VTY lines password, go here.

Privileged mode of a Cisco device has some advanced IOS commands that can have disastrous consequences if used by wrong hands. So it is very important to set up a password to access privileged commands. Use the following commands

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The “enable” command takes us into privileged mode. The “conf t” mode takes us into global configuration mode which pertains to the configuration settings of the whole switch. The “enable password”  sets a password for the privileged mode. ‘123456’ is the password. The “exit”  command takes us out of the privileged mode. To see if a password has been set for the privileged mode, try entering into privileged mode by typing “en” command. We can see that it prompts us for the password.