What is a Denial of Service attack?
A Denial of Service (DoS) Attack is any attempt to make an Internet-based service unavailable or unusable. In the real world a denial of service attack is not being able to use the automatic teller machine because someone has stuck chewing gum in it. For the Internet it means not being able to access a web site. Most of the biggest web sites have been hit by DoS attacks and www.microsoft.com is no exception.
Denial of Service (DoS) is an attack designed to render a computer or network incapable of providing normal services. The most common DoS attacks will target the computer’s network bandwidth or connectivity. Bandwidth attacks flood the network with such a high volume of traffic, that all available network resources are consumed and legitimate user requests can not get through. Connectivity attacks flood a computer with such a high volume of connection requests, that all available operating system resources are consumed, and the computer can no longer process legitimate user requests. The high-profile attacks of the week of February 6th, 2000 were primarily bandwidth attacks, and all of the targets were high-profile internet web sites. A complete description of Denial of Service attacks is available from CERT on http://www.cert.org/tech_tips/denial_of_service.html.
A denial of service (DoS) attack is an attempt to make a website or another Internet resource unavailable to users. Denial of service attacks may be very costly, as businesses lose money and customers every hour they are unavailable; they are generally illegal, and they also violate the Internet Architecture Board’s proper use policy. The traditional denial of service attack is executed by flooding the targeted server with dummy requests, overloading it and preventing it from handling legitimate traffic; other types of attacks include severing the network connection entirely, crashing the server, or shutting down the service for one particular person or group. Denial of service attacks based on traffic overload are usually very easy to launch; the primary requirement is large amounts of bandwidth. If the target server is flooded with more requests for data than it has bandwidth for, valid requests will be unable to get through, and the server’s owner may also be billed for excessive ba
In a denial-of-service (DoS) attack, an attacker attempts to prevent legitimate users from accessing information or services. By targeting your computer and its network connection, or the computers and network of the sites you are trying to use, an attacker may be able to prevent you from accessing email, web sites, online accounts (banking, etc.), or other services that rely on the affected computer. The most common and obvious type of DoS attack occurs when an attacker “floods” a network with information. When you type a URL for a particular web site into your browser, you are sending a request to that site’s computer server to view the page. The server can only process a certain number of requests at once, so if an attacker overloads the server with requests, it can’t process your request. This is a “denial of service” because you can’t access that site. An attacker can use spam email messages to launch a similar attack on your email account. Whether you have an email account suppli
A denial-of-service (DoS) attack causes your computer to crash or to become so busy processing data that you are unable to use it. Examples include attempts to: “flood” a network, thereby preventing legitimate network traffic disrupt connections between two machines, thereby preventing access to a service; prevent a particular individual from accessing a service; disrupt service to a specific system or person. Not all service outages, even those that result from malicious activity, are necessarily denial-of-service attacks. Other types of attack may include a denial of service as a component, but the denial of service may be part of a larger attack. Legitimate use of resources may also result in denial of service. For example, an intruder may use your anonymous ftp area as a place to store illegal copies of commercial software, consuming disk space and generating network traffic.
