Distributed denial of services attack is a case where by a hacker uses you own computer to assault another computer. If any attacker gains access to you computer machines due to faulty security systems, they can use it to send huge amounts of information to certain web addresses. They can also use it to send spam message to a particular mail address.  

The attack is termed distributed since the hacker uses more than one computer to accomplish the attack. The hacker then uses your computer to launch the DDoS attack. They normally use this method in order to hide their identity. Because hacking is a crime the attackers use other people’s computers to avoid, being caught up.   

There are about four types of DDoS attack. They include interruption of design information, interruption of network components, flocking of network resources and interruption of the functionality of an operating system.  All these types of attack create many inconveniences. They result to slow response or no response of the site under attack.

There some changes on you system that can help you know if you are under a DDoS attack. Such changes include excess slowness of your network, unavailability of inability to reach some websites and increase spam messages. The most common of these changes is unavailability of websites. The websites that you cannot reach are the ones under attack.

If you think that, you are under DDoS attack you can use the diagnostic commands found in Linux command line shell. The tools can help you determines the host and terminate the attack.

1. Use the ethereal command to monitor your network traffic. This will help you to determine the source of the attack. When you identify the sourced, locate where the attack heading. 
2. On you server, locate the server load. There are various commands used to locate the server load. They include top w and uptime. Other commands that help in determining the processes that are consuming many resources include ps and top that.
3. Once you have identifies go ahead and a stop them using the -Kill http command.  

These attacks are very common. However, they can be can be avoided by

1. Restrict ping access to avoid ping access.
2. Make sure your firewall is one and you have the most recent DDoS utilities. Examples of DDoS utilities include rootkit, APF, DDoS, APF among others.  
3. Inspect your host machines to find any vulnerable programs.
4. Come up with a load balancing measure to ensure equal distribution of load from the server.
5. Analyze your network to determine the kind of attacks directed to it.
6. Avoid free software from unrecognized sources on the internet.
7. Install an antivirus on your system
8. Create a general audit plan for your machines

DDoS attacks should not stress you because they are avoidable. If you do not controlled them they can result in slow performance of your machine. In addition, they can result in total breakdown of your machine. This means that you lose valuable information in your computer.