LFCS Networking Practice Question
A Linux server hosts a critical web application and is connected to the corporate network via a bonded interface bond0, combining eth0 and eth1 in active-backup mode. The server has a static IP 192.168.1.100/24 and default gateway 192.168.1.1. Recently, users report intermittent connectivity. The administrator runs 'ip link show' and sees that eth0 and eth1 are both state UP, but bond0 shows 'state UP' and 'NO-CARRIER'. The bond primary slave is eth0. Also, 'ping 192.168.1.1' fails. What should the administrator do next?
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
✓
Check the physical cable connection of eth0.
The bond interface showing NO-CARRIER indicates a physical link problem on the active slave. Since eth0 is the primary slave and bond0 has no carrier, the most likely cause is a disconnected or faulty cable on eth0. Checking the physical connection is the appropriate first step. Changing the bond mode or restarting services would not resolve a physical issue, and adding a secondary IP is irrelevant.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Add a secondary IP address to eth0.
Why it's wrong here
Adding a secondary IP does not address the missing carrier; it is irrelevant to connectivity.
- ✗
Restart the NetworkManager service.
Why it's wrong here
Restarting NetworkManager is unlikely to resolve a physical link issue and may cause temporary disruption.
- ✓
Check the physical cable connection of eth0.
Why this is correct
NO-CARRIER on the bond with the primary slave UP suggests a physical problem on eth0; checking the cable is the correct first step.
- ✗
Change the bond mode to balance-rr to load balance traffic.
Why it's wrong here
The bond mode is not related to the carrier status; changing mode will not fix a physical link issue.
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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.