What is a denial of service attack?

A denial of service attack is a broad series of attacks that malicious users carry out to prevent actual users from accessing the service in question.

The basic process for carrying out this attack is that malicious users send excessive messages to the service requesting information. This results in the service exhausting its resources preventing legitimate requests to be fulfilled. The source address of these requests are invalid and as a result, the service spends a lot of time finding the fake address. This time results in multiple open connections which prevent actual users from accessing the busy network service. Once the service closes the fake request, the attacker sends in more requests, keeping the service network busy.

Types of DOS attacks

• When the network is flooded, an attacker sends a large number of requests to the service resulting in authentic users being unable to access the service, i.e. they cannot open their own connections with the service network.

• Another form of DOS attack is more targeted. The attacker can prevent a particular user from accessing the service network as opposed to all users.

• A DOS attack can also interrupt a connection between two interacting systems such that they cannot use the service any longer.

Along with these, there are multiple other types of DOS attacks. These attacks are harmful to the service as they render it ineffective and inaccessible. It prevents authentic users from accessing the site and creates traffic in the network.