Denial of service - BZU PAGES: Find Presentations, Reports, Student's Assignments and Daily Discussion; Bahauddin Zakariya University Multan

**.BZU.** · #2 21-09-2008, 03:59 PM

What is a distributed denial-of-service (DDoS) attack?

In a distributed denial-of-service (DDoS) attack, an attacker may use your computer to attack another computer. By taking advantage of security vulnerabilities or weaknesses, an attacker could take control of your computer. He or she could then force your computer to send huge amounts of data to a web site or send spam to particular email addresses. The attack is "distributed" because the attacker is using multiple computers, including yours, to launch the denial-of-service attack. How do you avoid being part of the problem?

Unfortunately, there are no effective ways to prevent being the victim of a DoS or DDoS attack, but there are steps you can take to reduce the likelihood that an attacker will use your computer to attack other computers:

Install and maintain anti-virus software (see Understanding Anti-Virus Software for more information).

Install a firewall, and configure it to restrict traffic coming into and leaving your computer (see Understanding Firewalls for more information).

Follow good security practices for distributing your email address (see Reducing Spam for more information). Applying email filters may help you manage unwanted traffic.

How do you know if an attack is happening?

Not all disruptions to service are the result of a denial-of-service attack. There may be technical problems with a particular network, or system administrators may be performing maintenance. However, the following symptoms could indicate a DoS or DDoS attack:

unusually slow network performance (opening files or accessing web sites)

unavailability of a particular web site

inability to access any web site

dramatic increase in the amount of spam you receive in your account

What do you do if you think you are experiencing an attack?

Even if you do correctly identify a DoS or DDoS attack, it is unlikely that you will be able to determine the actual target or source of the attack. Contact the appropriate technical professionals for assistance.

If you notice that you cannot access your own files or reach any external web sites from your work computer, contact your network administrators. This may indicate that your computer or your organization's network is being attacked.

If you are having a similar experience on your home computer, consider contacting your Internet service provider (ISP). If there is a problem, the ISP might be able to advise you of an appropriate course of action.