CompTIA PenTest+ (PT0-003)Reconnaissance and EnumerationHard

A penetration tester is performing an internal assessment. They have compromised a Windows workstation and want to quickly identify other active hosts on the same local subnet. They need a command that leverages the Windows operating system's native capabilities for host discovery. Which command is most effective for this purpose?

  1. Aping -n 1 -w 100 <target_ip>
  2. Bfor /L %i in (1,1,254) do @ping -n 1 -w 100 192.168.1.%i | findstr "Reply from"
  3. Carp -a
  4. Dnmap -sn <target_subnet>
Show answer & explanation

Correct answer: B. for /L %i in (1,1,254) do @ping -n 1 -w 100 192.168.1.%i | findstr "Reply from"

The `for /L %i in (1,1,254) do @ping -n 1 -w 100 192.168.1.%i | findstr "Reply from"` command is a native Windows command-line technique for performing a ping sweep across a local subnet. It iterates through IP addresses (1-254 in the last octet) and pings each one, then filters the output to show only replies, effectively identifying active hosts.

Why the other options are wrong

  • A. `ping -n 1 -w 100 <target_ip>` pings a single host, not an entire subnet.
  • C. `arp -a` displays the local ARP cache, which only shows hosts the system has recently communicated with, not all active hosts on the subnet.
  • D. Nmap is a third-party tool, not a native Windows capability, though it can be installed.

Windows Command Line Ping Sweep

A native Windows command-line technique to perform host discovery (a ping sweep) across a local subnet. It uses a `for` loop to iterate through a range of IP addresses, sending an ICMP echo request (ping) to each and filtering the output to identify active hosts.

  • Uses `for /L` loop for iteration.
  • Leverages `ping` command for ICMP echo requests.
  • Filters output with `findstr` to show only replies.
  • Native to Windows, no external tools required.
  • Useful for quick host discovery on a local subnet.

Memory trick: The 'for' loop pings through the network, finding replies like treasure.

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