Understanding DDOS - DDOS attacks (Denial Distribute of services) Attack, is probably the most simple attacks done but the effect is very dangerous.
Large sites such as yahoo.com, ebay.com, hotmail.com, e-gold.com, 2checkout.com and others had experienced an attack that resulted in his site could not be accessed for several hours.
The latest is the site e-gold.com in 2005 yesterday, his site was attacked using methods DDOS (Denial Distribute of services).
How does the DDOS?
If you use Windows program, trying to do this on your computer.
1. Start, Programs, Accessories, Command Prompt
2. Then at the command prompt type, ping -t www.situsyangdituju.com
or it could be the Start, Run, Ping -t www.example.com
Then your computer will send a packet of information to the site in the heading above, basically by the command of your computer sends a greeting "Hello, is anyone there?", To a site on the go earlier. then the site server in the heading before sending the answers back by saying: "Yes, here there are people"
Now imagine, if there are thousands of computers, at the same time perform the command at the site on the go. 1 computer sends data at 32 bytes / sec to sites on the go. If there are 10,000 computers simultaneously perform the command, it means that no data items amounted to 312 Mega Bytes / sec which is accepted by the site on the go earlier.
And the server of the site that the tenor had had to respond to mails sent from 10,000 computers simultaneously. If the 312 MB / sec of data that must be processed by the server, in 1 minutes, the server must process the shipment data of 312 MB x 60 seconds = 18720 MB. Can guess, the site is attacked by this method will have Over Load / overload of data, and are not able to process the shipment data come.
Her question, how 10,000 computers can join the attack?
Other computers which undertook the attack called zombie computers, which had been infected with some kind of adware. so the attacker just ordered a main computer to send commands to the zombie computers are already infected in order to carry out Ping to sites on the go. Hence the importance of a firewall on your computer, to monitor the packets outgoing and incoming from your computer.