Most Web users have at some point or another come across the term 'DDoS attack' - but what exactly does this mean?
DDoS - or distributed denial of service - attacks are attempts to make a computer, server or whole network unavailable to users. Why this is done, who is being targeted and how the attacks are carried out can vary significantly, but in essence, the objective of a person or group launching a DDoS attack is to disrupt/ suspend - either temporarily or indefinitely - services provided by the targeted Internet-connected host.
Targets typically include banks, credit card gateways, root name servers and other high-profile servers. It has, however, also been known for certain groups/ individuals to target local, regional and national government servers in order to 'make a point'. Considered to violate the IAB's proper Internet use policy; acceptable use policies of just about every Internet service provider and many national and international laws, DDoS attacks may, however, target anyone at any time.
Preventative measures include, for instance, Firewalls; ACL capable, rate-limiting switches and/ or routers; intelligent front end hardware and various IPS based measures involving continual monitoring and filtering of data; cleaning or 'scrubbing' centres (proxies, direct circuits, tunnels) and more.