Enumeration
⏱ ~3-min readAceMark Guide
What this topic is really about
ss -tln lists listening TCP sockets without root; -p adds process info where permitted. A SYN scan against localhost works but is overkill. iptables shows firewall rules, and /etc/services is a static name-to-port map.
-p- tells Nmap to scan all 65535 TCP ports rather than just the default top 1000, useful for finding services on uncommon ports. A ping-only scan is -sn, and -F scans a small fast list, not all ports.
See the mechanism
ss -tln lists listening TCP sockets without root; -p adds process info where permitted. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.
An exam-style question, fully explained
During Linux enumeration, which command lists listening TCP services without requiring root?
- Identify what the question tests: During Linux enumeration, which command lists listening TCP services without requiring root.
- ss -tln lists listening TCP sockets without root; -p adds process info where permitted.
- A SYN scan against localhost works but is overkill.
- iptables shows firewall rules, and /etc/services is a static name-to-port map.
Traps the examiner sets
- Read each option carefully — distractors on Enumeration are designed to look plausible.
- Re-check the exact wording of the question stem before committing to an answer.
- Watch the qualifiers ("always", "only", "except") that flip a correct-looking option.
Test your recall
Answer each from memory — you'll see instantly whether you're right and why.
Run a focused 10-question mini-mock on Enumeration and see it stick.
Practice more of this topic →