Which tool provides a list of open ports on network devices?

Which tool provides a list of open ports on network devices?

• A. Wireshark
• B. Nessus
• C. Nmap/Zenmap
• D. Metasploit

Answer: (C)

Identifying open ports on network devices through scanning is about mapping the reachable services on a network to understand the attack surface. The tool that best provides an explicit list of open ports on one or more hosts is Nmap, with Zenmap offering a GUI wrapper for easier use. Nmap uses various scan techniques to probe target hosts and report which ports are open, closed, or filtered, often accompanied by service detection to guess what software is listening on those ports. This direct, organized output is exactly what you need to inventory exposed endpoints and plan security measures. Wireshark, while powerful for examining live traffic and diagnosing network activity, doesn’t systematically enumerate open ports on devices; it analyzes packets rather than listing listening services. Nessus is a vulnerability scanner that identifies potential issues and misconfigurations and may perform port discovery as part of its checks, but its main goal is vulnerability assessment, not producing a straightforward open-port inventory. Metasploit is focused on exploitation and post-exploitation activities, not on discovering open ports for inventory purposes.

Identifying open ports on network devices through scanning is about mapping the reachable services on a network to understand the attack surface. The tool that best provides an explicit list of open ports on one or more hosts is Nmap, with Zenmap offering a GUI wrapper for easier use. Nmap uses various scan techniques to probe target hosts and report which ports are open, closed, or filtered, often accompanied by service detection to guess what software is listening on those ports. This direct, organized output is exactly what you need to inventory exposed endpoints and plan security measures.

Wireshark, while powerful for examining live traffic and diagnosing network activity, doesn’t systematically enumerate open ports on devices; it analyzes packets rather than listing listening services. Nessus is a vulnerability scanner that identifies potential issues and misconfigurations and may perform port discovery as part of its checks, but its main goal is vulnerability assessment, not producing a straightforward open-port inventory. Metasploit is focused on exploitation and post-exploitation activities, not on discovering open ports for inventory purposes.