LFCS Networking Practice Question
A Linux server has two interfaces: enp3s0 (192.168.10.5/24) and enp4s0 (10.0.0.5/24). The default route is via 192.168.10.1. A junior admin adds a static route to 10.1.0.0/16 via 10.0.0.1 using the command: ip route add 10.1.0.0/16 via 10.0.0.1. After this, users report that traffic to 10.1.1.0/24 fails. Which command should the administrator run to confirm that the kernel is selecting the correct route and interface for destination 10.1.1.10?
⚠ Common exam trap
The trap here is assuming that adding a static route guarantees it will be used, without verifying the kernel's actual route selection for the destination.
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
✓
ip route get 10.1.1.10
The kernel chooses routes based on longest prefix match and metric. To verify which route and interface are selected for a specific destination, the ip route get command is used. It performs a route lookup and displays the resolved source address, gateway, and output interface, directly answering why traffic to 10.1.1.0/24 may fail despite a static route being added.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
ip route get 10.1.1.10
Why this is correct
This command asks the kernel which route and source address it would use for the destination, showing the resolved interface and gateway. In this scenario, it would reveal whether the static route via 10.0.0.1 is chosen or whether the default route via 192.168.10.1 is used instead, directly diagnosing the reported failure.
- ✗
ip -s link show enp4s0
Why it's wrong here
This displays statistics and status for enp4s0, such as packets transmitted and received, but it does not show routing decisions. It cannot confirm whether the static route via 10.0.0.1 is being used for 10.1.1.10, making it unsuitable for diagnosing the routing problem.
- ✗
ip route show table all
Why it's wrong here
This lists all routes in all tables but does not simulate the lookup for a specific destination. It would not tell the administrator which interface or gateway the kernel selects for 10.1.1.10, so it fails to answer the core question of route selection in this scenario.
- ✗
traceroute -n 10.1.1.10
Why it's wrong here
Traceroute shows the path packets take, which can help identify where traffic stops, but it does not directly reveal the kernel's route selection logic or which local interface and gateway are chosen. It is less precise than a route lookup for confirming the selected route.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Linux Foundation exam blueprint
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.