Ravi Sir's Cyber Security Cards › Interview Cards
How do you list listening ports on Linux?
How do you list listening ports on Linux? Use ss -tulnp (or netstat) and compare what you see to a known baseline. On a lab web server you expect sshd and the web service, not a strange high port (a possible reverse shell). “I list listeners with ss -tulnp and flag anything that isn’t on my baseline
Read card text
What this card says
Short answer
Use ss -tulnp (or netstat) and compare what you see to a known baseline.
Example
On a lab web server you expect sshd and the web service, not a strange high port (a possible reverse shell).
Say it in the interview
“I list listeners with ss -tulnp and flag anything that isn’t on my baseline.”
Why it matters
An unexpected listening port is often the first sign of a backdoor.
Learn more in the lesson: 46.3 Linux on EC2 Interview Questions