Cisco CS Foundation: System Monitoring & Troubleshooting

This question assesses your ability to monitor and troubleshoot processes and network bindings on Linux/Unix systems using command-line tools.

You will be asked to locate running programs, identify their PIDs, and verify which network ports or sockets they own. Expect to use commands such as ps, pgrep, top/top -H, and htop to inspect process lists and resource usage. For network inspection you should be comfortable with netstat, ss, and lsof (or combinations like lsof -i), and know how to correlate a socket or port to a PID. You’ll also demonstrate practical verification: checking process status, tailing or grepping logs, and testing connectivity with curl, telnet, or nc.

Interviewer flow: you may start with a simple prompt to find a process by name or port, then be asked to explain how you’d confirm the process is functioning (logs, health endpoints), and finally to outline remediation steps (restart, graceful shutdown, SIGTERM vs SIGKILL). They may introduce follow-ups like intermittent connectivity, zombie processes, or a service bound to the wrong interface.

Skill signals: show command fluency, ability to map ports→PIDs, basic networking knowledge (TCP vs UDP, IPv4/IPv6), familiarity with process signals and system logs, and pragmatic troubleshooting steps. Emphasize reproducible checks and safe remediation (graceful restart, log analysis) when answering.