How to do DNS SPOOF(tutorial)?

First What is the DNS ?(wikipedia.org)

The Domain Name System (DNS) is a hierarchical naming system for computers, services, or any resource connected to the internet or a private network. It associates various information with domain names assigned to each of the participants. For example, http://www.example.comtranslates to208.77.188.166.

What does poisoning the DNS allow us to do ?

It allows us to redirect the traffic to another website.
First This is the structure of the network :

1 , 2 and 3 are computers
1 is the computer being the gateway (could be a router) (172.128.254.1)
2 is the target computer (172.128.254.10)
3 is the attacker using cain
Note: IPs are just used for this tutorial and chosen randomly.
Our work is on computer number 3 :
1-After you install cain , open it and go to the sniffer tab
2-Click on configure and choose your adapter

3-Enable the sniffer (click on the second icon in the toolbar next to the open icon)
4-Right click in the empty area and choose scan MAC addresses. We get the results above.
5-Click on the APR Tab
 

6-Click on the + sign in the toolbar to add a new ARP poison routing

7-choose the gateway which is 172.128.254.1, in the next list you�ll get the IP of the computer 2 which is 172.128.254.10and click ok

8-now click on the APR-DNS tab

9-click on the + sign

10-enter the web address that you want to spoof , (in this case when the user goes to facebook he�ll be redirected to myspace) click on resolve type the web address that you want to redirect the user to it, and click ok, and you�ll get the IP of the web address, then click ok

 

you'll get something like this:

11-now to make this work we have to enable APR poisoning , click on the icon next to the sniffer icon, and everything should work as we expect.

Now the computer 2 will get the routes poisoned and when the user requests http://www.facebook.comhe will be redirected to http://www.myspace.com.
Imagine what you can do with this technique.