Flooding network ports is an example of which type of attack?

A Man-in-the-Middle (MitM) attack involves an attacker secretly relaying and possibly altering the communication between two parties who believe they are directly communicating with each other.

A brute force attack involves systematically trying every possible combination to guess credentials or cryptographic keys, rather than overwhelming network resources.

A Denial of Service (DoS) attack, or its distributed form (DDoS), seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the Internet. Flooding network ports with a high volume of packets is a common method to achieve this.

A birthday attack is a cryptographic attack that exploits the mathematics behind the birthday problem in probability theory, used to find collisions in hash functions.