Network Issues and Denial of Service Attacks
03/02/2011
Earlier this week one of our servers was affected by a Denial of Service Attack. We initially reported this as a network issue as this is increasingly how Denial of Service Attacks appear, in that they affect more than one server.
What is a Denial of Service Attack?
A DoS attack (denial of service attack) or DDOS attack (distributed denial of service attack) is an organised effort to bring down a server by sending too much traffic through its network.
These are becoming increasingly popular and the targets are usually large websites or data centres hosting major websites. The simpler DoS attacks and being replaced by more coordinated DDoS attacks which are needed as server security and backups increases.
How are Denial of Service Attacks caused?
The most common methods is to send so many external communications requests to a server or network that it responds slowly and gradually stops completely.
DoS attacks usually target websites and servers which have high security and firewalls and systems in place to prevent such attacks.
How can you prevent these attacks?
Good hosting companies use multiple networks and redundancy to ensure a single failure does not cause loss of service, and preventing DoS attacks are routine for many hosting providers. Dealing with DDoS attacks is more of a challenge. A good support team available 24/7 is needed to take manual action to locate and isolate the source of the DoS attack.
In order to reduce the threats of these attacks we host websites in multiple locations using multiple hosting companies. Using multiple suppliers helps when any attack is on the network as this is more likely to be isolated to a few hosting providers.
For business critical websites we can provide redundant hosting enabling websites to still be visible if one data centre is out of action for while. This is most common for ecommerce styles websites or businesses which rely on high numbers of lead generation daily from the website.
