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312-50V10 · Question #853

You have successfully comprised a server having an IP address of 10.10.0.5. You would like to enumerate all machines in the same network quickly. What is the best Nmap command you will use?

The correct answer is B. nmap -T4 -F 10.10.0.0/24. The -F (fast) flag limits Nmap to the 100 most common ports instead of the default 1000, making it the fastest option for enumerating live hosts across a subnet.

Scanning Networks

Question

You have successfully comprised a server having an IP address of 10.10.0.5. You would like to enumerate all machines in the same network quickly. What is the best Nmap command you will use?

Options

  • Anmap -T4 -q 10.10.0.0/24
  • Bnmap -T4 -F 10.10.0.0/24
  • Cnmap -T4 -r 10.10.1.0/24
  • Dnmap -T4 -O 10.10.0.0/24

How the community answered

(22 responses)
  • B
    86% (19)
  • C
    5% (1)
  • D
    9% (2)

Why each option

The -F (fast) flag limits Nmap to the 100 most common ports instead of the default 1000, making it the fastest option for enumerating live hosts across a subnet.

Anmap -T4 -q 10.10.0.0/24

The -q flag is not a valid Nmap option, making this command syntactically invalid and non-functional.

Bnmap -T4 -F 10.10.0.0/24Correct

The -F flag enables fast scan mode, reducing the port range to the 100 most common ports and significantly cutting scan time for an entire /24 subnet. Combined with -T4 (aggressive timing), this is the optimal combination for quickly discovering active machines and services on the 10.10.0.0/24 network where the compromised host resides.

Cnmap -T4 -r 10.10.1.0/24

The -r flag only changes port scanning order to sequential (non-random) and also targets the wrong subnet 10.10.1.0/24 instead of 10.10.0.0/24 where the compromised host resides.

Dnmap -T4 -O 10.10.0.0/24

The -O flag enables OS detection, which is a slower, resource-intensive probe not designed for rapid host enumeration across an entire subnet.

Concept tested: Nmap fast scan flag for subnet enumeration

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

Topics

#Nmap#network enumeration#fast scan#subnet scanning

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