Run ss -tulpn.
ss -tulpn
Mission 187
Network listener triage
Compare sockets, firewall, and config.
Troubleshootingssufwgrep
Lesson 187 of 360
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Troubleshooting · 8 minutes
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learner@clairos:/home/learner $
Unix ops lab: type a command, press Enter
Instructions
8 minutes
Click any instruction for the command details, the why, and the common mistake to avoid.
Run ufw status.
ufw status
Run grep listen /etc/nginx/sites-available/learn.conf.
grep listen /etc/nginx/sites-available/learn.conf
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Lesson support
What to notice while you play.
Compare sockets, firewall, and config.
Run the commands in order and compare the outputs.
Junior operators build confidence by gathering evidence before changing systems.
- Skipping the inspection step.
- Assuming one command tells the whole story.
Reference
Commands in this lesson.
grep [-i] <text> <file>
Find literal text inside a file.
ss|ip
Inspect simulated sockets and addresses.
ssh|scp|ssh-keygen
Practice SSH inspection and dry-run transfer shapes without network access.
ufw status
Inspect simulated firewall rules.