What type of attack seeks to overwhelm a system with traffic?

A Denial-of-Service (DoS) attack is characterized by its objective to disrupt the normal functioning of a targeted server, service, or network by overwhelming it with a flood of traffic. The primary goal of the attacker is to make the targeted resource unavailable to legitimate users, often by saturating the bandwidth or crashing the system resources.

In a DoS attack, various methods may be employed to generate an excessive amount of traffic, which can overwhelm the capabilities of the server or network. This causes legitimate requests to be dropped or delayed, effectively denying access to users. Understanding this is crucial in network security, as it helps in implementing proper defenses such as rate limiting, traffic analysis, and other mitigation strategies.

The other types of attacks mentioned—brute force, phishing, and man-in-the-middle—do not focus on overwhelming a system with traffic. A brute force attack involves attempting multiple combinations to guess passwords, phishing is about tricking users into revealing sensitive information, and a man-in-the-middle attack is centered on intercepting communication between two parties. Therefore, the specific nature and intent of a DoS attack align perfectly with the description provided in the question.