What does the --max-retries option do, and how does adjusting it affect scan reliability and duration?

What does the --max-retries option do, and how does adjusting it affect scan reliability and duration?

• A. Controls the number of retries per probe; higher retries improve reliability but increase duration; lower retries speed up scans but may miss results
• B. Sets the maximum number of retries across hosts
• C. Sets the maximum times a host will attempt to connect a port
• D. Controls the randomization of host order

Answer: (A)

The option controls how many times Nmap will retransmit each probe to get a definitive answer. Increasing retries means Nmap will make more attempts for every port/host probe, which boosts the chance of catching a valid result when the network is lossy, filtered, or slow. That improves reliability of detection, but it also lengthens the scan because each probe takes more time to be retried. Reducing retries speeds up scans but raises the risk of missing results if responses are occasionally dropped or delayed. This setting affects retries on a per-probe basis, not across hosts, not about how many connections a host will attempt, and not about host-order randomization.

The option controls how many times Nmap will retransmit each probe to get a definitive answer. Increasing retries means Nmap will make more attempts for every port/host probe, which boosts the chance of catching a valid result when the network is lossy, filtered, or slow. That improves reliability of detection, but it also lengthens the scan because each probe takes more time to be retried. Reducing retries speeds up scans but raises the risk of missing results if responses are occasionally dropped or delayed. This setting affects retries on a per-probe basis, not across hosts, not about how many connections a host will attempt, and not about host-order randomization.