Table of Contents
What is a DDoS attack
A DDOS attack is an assault on a network, typically over the Internet, by flooding it with network traffic so as to make it unusable. It can be used as a means of protest, to prevent access to specific websites, or to disrupt service. DDos attacks are often conducted using “botnets,” computers compromised by malware and controlled remotely.
The DDoS defense systems used in online games are well-developed and provide adequate protection for most games (due to the size of the playerbase, a DDoS attack would affect at least some users). For higher-profile games, DDOS protection is often purchased from specialist companies.
Perhaps the most famous case of DDOS attacks occurred in late 2000, when pro-Chinese hackers attacked the website of Falun Gong with the purpose of shutting it down. The attacks caused widespread chaos on many U.S. web services and affected Web sites around the world.

How long do they last
DDos attacks come in many sizes, and can last for just a few minutes, or continue for days. Those perpetrating a DDos attack often target network infrastructure such as routers and servers, causing computers connected to the servers to lag or crash. When DDos attacks are the largest online protests they can last days. Larger attacks have targeted banks, for example in Estonia in May 2007 and against Sony’s Playstation network. A DDoS attack is a form of DOS attack, but typically lasts longer and is less focused on a small number of specific targets.
According to one report, it costs an organization on average $200,000 in lost revenues for each hour a DDoS attack occurs. Some attacks, such as the one against Estonian web sites, have been much larger and cost companies millions of dollars in lost business. A DDoS attack can last for just a few minutes or go on for days.

Who are the targets
Much of the attention in recent DDos attacks has been on targets within the United States. This appears to be partly a function of the US government’s aggressive use of surveillance and other activities designed to keep tabs on its own citizens. SOPA, for example, was an anti-piracy bill that sought to force sites such as Wikipedia and Youtube to remove content that is in violation of intellectual property laws. The “kill switch” provision in SOPA allowed the government to essentially shut down those sites by taking them offline. Anonymous also launched attacks against MasterCard, Paypal and Amazon in retaliation for their refusal to process donations for Wikileaks. They also attacked the U.S. Department of Justice, Universal Music Group and the Motion Picture Association of America (MPAA).
As of this writing, none of these attacks has been successful in shutting down any sites or Internet services. Where DDos attacks are concerned, nothing ever is 100% effective. Still, these are notable targets. The DoJ and FBI are the federal agencies that have been tasked with tracking down Anonymous members to prosecute them for their various online activities. Mastercard, Paypal and Amazon all depend on the Internet for business so it is not surprising that they were attacked. It is clear that Anonymous considers SOPA to be a grave threat and has actively attempted to stop it. The attack on the MPAA and other entertainment industry groups also make sense given the history of online activity by members of Anonymous.
What can be done to prevent them or mitigate their effects
It should be noted that cyber attacks are not just a matter for the military and government agencies. In one case, DDoS attacks have been used to extort money from private companies. “A threat of DDoS may be enough for the extortionist to collect his payment, especially if the victim does not have an effective solution in place.” “Solutions” can take the form of hiring a specialized security firm which is highly skilled in dealing with DDos attacks. The firm would be able to watch and monitor the situation, knowing when a DDoS attack is imminent and how to respond.
DDoS attacks are primarily a high bandwidth problem.The primary means of mitigating these attacks is through blocking, filtering or throttling incoming traffic such that the assault on the victim site fails or at least has significantly less impact. Bandwidth management is used to reduce the bandwidth available to a specific user or set of users. This is generally not effective against sophisticated DDoS attacks because an attacker with sufficient resources can simply increase traffic volume.Bandwidth management can be used, however, to conserve bandwidth in order to deal with large volumes of legitimate traffic.

Are they becoming more common and more sophisticated
DDos attacks have become increasingly common at the very least, and have become increasingly sophisticated. A DDos attack on India’s largest airline in 2012 blocked more than 100,000 IP addresses, while a 2013 attack on the BBC last more than 4 days. The attacks are becoming increasingly sophisticated in their methodologies, with new types of DDos attacks invented to bypass security measures. Are they becoming more prevalent and sophisticated in their methods?
(3) Source: “How long do ddos attacks last” : http://www.ibtimes.co.uk/how-long-do-ddos-attacks-last-1540528
(4) Source: “Are they becoming more common and more sophisticated” : http://www.forbes.com/sites/larrybell/2014/09/29/are-they-becoming-more-common-and-more-sophisticated/#27c0a7d3772f
Comments (Brief background knowledge needed)(to use as knowledge, not to be copied verbatim):”how long do ddos attacks last” : “Are they becoming more common and more sophisticated”
