‫So let's see how we can perform a DHC starvation attack and consume the DHP pool using Yersinia Yersinia
‫is a network tool designed to take advantage of some weaknesses in different network protocols.
‫The protocols currently implemented in your cinema are shown in this light.
‫Now we're going to use our VMS in that mode during this demo.
‫So I'm on my house machine and open the virtual machine library.
‫This is the collie that I'll use.
‫So click this icon to see the VM settings, click the network adapter icon.
‫It says Internet is shared with my Mac, so if you look the explanation in the right hand side of the
‫frame, it means the VM is in that mode.
‫So this is what we want.
‫So just leave it as it is.
‫The Connect network adapter is selected, so Carly is ready to use with a net network connection.
‫So Windows eight is the other VM that I used to demonstrate DHP starvation attack.
‫Let's have a look at the network settings of windows as well.
‫Yeah, it's in that mode and the network adapter is connected.
‫So I'll disconnect the network adapter by clicking here because I just want to show you that the DHP
‫of VMware is working properly.
‫So I want to add a second network interface for my Windows system, click show all and go to the Settings
‫menu and click on Add Device at the upper left hand corner, select network adapter and click Add the
‫details of the new adapter listed here.
‫The that mode is selected by default already.
‫So uncheck the Connect network adapter box for now.
‫OK, so as you see, we have two network adapters for the Windows system.
‫Both of them are in that mode and are disconnected.
‫So now I'll start the Windows eight system.
‫Log in.
‫And sure enough, it's ready.
‫Right click on a network icon at the lower right corner and select open network and sharing center.
‫And right there, we don't have an active network at the moment.
‫That's to be expected.
‫So now I connect the first adapter and activate the network.
‫In VMware Fusion, you can see and change the setting in several ways.
‫If you use the VM in full screen mode like I do.
‫Just go to the upper side for VMware Fusion menu.
‫There it is.
‫And if the menu does not appear, just press command control buttons together.
‫Right.
‫So this is the default setting of VMware Fusion to turn back to the host system when you're inside of
‫him.
‫And these are the network adapters, when you click on them, you'll see the short menu for network
‫adapter.
‫And here you can connect or disconnect the network adapter, change the network mode, Nat Bridge or
‫host only, and you can use this pop up for the network adapter settings.
‫Now, the second way to see and change in network settings is to click the Settings icon, then select
‫the adapter to see the settings.
‫So the third way is to go to the virtual machine menu.
‫Go to the network adapter and you'll see the short menu of the adapter.
‫Now go to the first network adapter icon and click on the Connect network adapter menu item and now
‫you see in the network and sharing center window.
‫We now have an active network connection.
‫So click the network name and the details button.
‫Here are the connection details, and right there, there it is, DHP is one seven two point one six
‫nine nine two two five four and it assigned an IP address for the VMM one seven two point one six nine
‫nine two two one, as well as the Gateway and the DNS address.
‫Now I'll go back to Carly and open a terminal screen.
‫Using the config command to see the network interface configuration, and sure enough, it has the IP
‫address.
‫So, Ping, the Windows eight system to validate the network.
‫Two to one.
‫OK.
‫We received the ICMP reply, so everything looks OK.
‫Now, is it time for your Cynthia, to take men your senior and hit enter, see the menu and right here
‫in the manual, your senior is a framework for performing layer two attacks.
‫And here's a list of protocols implemented in your senior.
‫Scroll down, you'll see the options we can use uppercase G to start a graphical interface.
‫So let's go ahead and use it in graphical mode.
‫Can press Q to quit from the manual and turn back to the terminal, now type your senior uppercase G.
‫And press enter.
‫So this is a graphical user interface of your cinema.
‫Before running the attack, let's open Wireshark and monitor the network packets to see what happens
‫when we start the attack.
‫You can type Wireshark in terminal to start it or just click the Wireshark icon to select the interface
‫to listen.
‫Double click eth0.
‫And to discard the different packets and focus only on the DHC packets, we can filter the packets in
‫the filter box type boot p and hit enter.
‫So Boot P is the short form of bootstrap protocol, which I mentioned earlier.
‫It's basically a computer networking protocol to automatically assign an IP address to network devices
‫from a configuration server.
‫And obviously, it's used by the DHCP server.
‫Now we can turn back to your city and prepare and run the attack.
‫So quick launch attack.
‫That's the link at the upper left hand corner.
‫The tabs in the window are the implemented protocols choose DHP and select sending Discover packet now
‫click OK.
‫As soon as we click the button, you're seniors start sending dozens of DHCP requests in a second.
‫It'll keep sending the packets till we stop the attack.
‫Now, look at the Wireshark window.
‫These are the DHP discover packets sent by Yersinia.
‫So now, while you're Cynthia is sending the HP Discover packet, let's activate the second interface
‫of the Windows VM, and let's see if the HP server assigns an IP address for the second interface.
‫All right, so we're in the Windows VM now, go to the second network adapter, click Connect Network
‫Adapter to to activate the second interface.
‫Now, do you remember what happened when we activated the first interface, we saw the new network activated?
‫But now there is still no network because the DHCP server is busy replying to the request created by
‫Yersinia, it's not going to answer the Windows eight second interface.
‫So let's turn back to Carly and stop the attack.
‫In your city is interface, just click list attacks and then click Stop or stop all.
‫In Wireshark window, look at the bottom of the package list, we now have a complete DHC sequence.
‫Discover, offer, request and act packets.
‫In the Windows eight VM, we now have a second network.
‫The first one was Ethernet zero two.
‫This one is even at zero.
‫Click on it.
‫In a status window, click on details.
‫The second interface has an IP address now assigned by the DHP server.