The CEH v13 content explains that stealth scanning involves modifying scan timing parameters to reduce packet frequency, randomize intervals, and avoid recognizable patterns typically flagged by intrusion detection systems. Slow, randomized timing—often achieved with Nmap’s T0 or T1 timing templates—prevents bursts of traffic and allows scans to blend into normal network noise. IDS/IPS systems tuned for high-volume events may fail to detect such gradual reconnaissance. Fast SYN scans generate distinctive patterns easily identified by security monitoring tools. UDP scans, especially across all ports, produce high traffic volume and are extremely noisy. Xmas scans, although sometimes used for stealth against stateless filters, are still signature-detectable and inappropriate when stealth over time is required. Therefore, applying slow, randomized timing options aligns with CEH-approved reconnaissance techniques for evading detection while enumerating open ports.