Courseiva
NetworkinghardMultiple SelectObjective-mapped

LFCS Networking Practice Question

Which TWO commands can display a list of active TCP connections listening on the system? (Choose two.)

⚠ Common exam trap

Test-takers frequently confuse commands that show network configuration (like `ifconfig` or `ip route`) with commands that show active socket states, leading them to pick options that display interface or routing information instead of listening TCP ports.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

ss -tuln

`ss -tuln` displays TCP (`-t`) and UDP (`-u`) sockets in a listening (`-l`) state with numeric (`-n`) addresses and ports, directly showing active TCP listening connections. Option D is correct because `netstat -tuln` performs the same function, listing TCP and UDP listening sockets with numeric output, and is the traditional tool for this purpose.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • ss -tuln

    Why this is correct

    Modern replacement for netstat; shows listening sockets.

  • nmcli connection show

    Why it's wrong here

    Shows NetworkManager connection profiles, not listening ports.

  • ifconfig

    Why it's wrong here

    Shows interface configuration, not listening ports.

  • netstat -tuln

    Why this is correct

    Displays listening TCP and UDP ports.

  • ip route show

    Why it's wrong here

    Shows routing table, not listening ports.

Visual reference

Client Server SYN (seq=100) SYN-ACK (seq=200, ack=101) ACK (ack=201) Connection established — data transfer begins

About these practice questions

Courseiva writes every LFCS question from scratch — 507 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

JA

Written by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

This LFCS practice question is part of Courseiva's free Linux Foundation certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the LFCS exam.