In a SYN flooding attack, randomizing the source IP address serves multiple purposes that enhance the attack's effectiveness and stealth. By using different source IPs, the attacker obscures their true identity, making it harder for defenders to trace the attack back to them. This technique also helps bypass network security measures designed to block traffic from known malicious IP addresses. Additionally, each SYN request ties up resources on the target server as it attempts to establish connections, and randomizing IPs allows the attacker to exhaust these resources more effectively, potentially leading to a denial of service. If a single IP address were used, it could be more easily identified and blocked, enabling the server to manage legitimate traffic better. Overall, randomization amplifies the impact of the attack while complicating mitigation efforts.