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LFCS · Question #412

Which of the following is NOT and valid scan technique with nmap?

The correct answer is E. RST. Nmap provides various port scanning techniques, but "RST" is not a named scan type; rather, a Reset (RST) flag is part of the TCP connection termination process observed during scans.

Submitted by marco_it· Apr 18, 2026Networking

Question

Which of the following is NOT and valid scan technique with nmap?

Options

  • AWindow
  • BSYN
  • CACK
  • DConnect()
  • ERST

How the community answered

(55 responses)
  • A
    2% (1)
  • C
    2% (1)
  • D
    5% (3)
  • E
    91% (50)

Why each option

Nmap provides various port scanning techniques, but "RST" is not a named scan type; rather, a Reset (RST) flag is part of the TCP connection termination process observed during scans.

AWindow

The Nmap Window scan (-sW) is a valid technique that exploits the TCP Window field to determine port status.

BSYN

The Nmap SYN scan (-sS), also known as "stealth scan," is a valid and common technique that sends SYN packets and watches for SYN/ACK or RST responses.

CACK

The Nmap ACK scan (-sA) is a valid technique used to map firewall rulesets and determine if ports are filtered or unfiltered.

DConnect()

The Nmap Connect() scan (-sT) is a valid technique that performs a full TCP three-way handshake, making it less stealthy but highly reliable.

ERSTCorrect

Nmap offers several named scan types such as SYN (stealth), Connect() (full connect), ACK, Window, and NULL/FIN/Xmas scans; however, "RST" is a TCP flag, not a dedicated Nmap scan technique.

Concept tested: Nmap scan techniques

Source: https://nmap.org/book/man-briefoptions.html

Topics

#nmap#port scanning#network scanning#TCP/IP

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