What is a primary reason for changing port numbers?

The primary reason for changing port numbers relates to increased security. By utilizing non-standard or custom port numbers, administrators can help protect services and applications from automated attacks and scanners that typically target well-known ports. Many attacks and malicious activities are designed to target default ports, such as port 80 for HTTP or port 22 for SSH. When services are moved to less commonly used port numbers, it becomes more difficult for attackers to identify and exploit them, thus enhancing the overall security posture of the system.

In addition to security benefits, changing port numbers can also help prevent direct access to services, thereby reducing the attack surface of a system. While fast communication, standardization, and compatibility are important in network design and management, they do not serve the primary intent of altering port configurations primarily for enhanced security.