hardMultiple ChoiceObjective-mapped
220-1201 Practice Question: A technician is troubleshooting a network where a…
A technician is troubleshooting a network where a single workstation cannot access any network resources. The link light on the NIC is solid, and the IP configuration shows an address of 192.168.1.100 with a subnet mask of 255.255.255.0. The workstation can ping its own IP but not the default gateway (192.168.1.1). What is the most likely cause?
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
✓
The switch port is configured with the wrong VLAN.
The workstation has a valid IP and can ping itself, indicating the NIC and stack are working. However, it cannot reach the gateway, which suggests a Layer 2 issue—likely an incorrect or missing default gateway configuration, or a VLAN mismatch on the switch port.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The DNS server is unreachable.
Why it's wrong here
DNS translates human-readable hostnames into IP addresses. When a technician is troubleshooting by pinging an IP address directly, DNS resolution is entirely bypassed. Therefore, an unreachable DNS server would not prevent a workstation from successfully pinging its default gateway's IP address, as this operation relies solely on Layer 3 IP connectivity and Layer 2 frame forwarding. The issue described points to a problem at a lower network layer, not application layer services like DNS.
- ✓
The switch port is configured with the wrong VLAN.
Why this is correct
If a workstation's switch port is configured for a VLAN different from the VLAN where its default gateway resides, Layer 2 isolation occurs. VLANs segment a physical switch into distinct broadcast domains, preventing direct communication between devices in different VLANs without a Layer 3 router. Consequently, even with correct IP addressing, the workstation's Ethernet frames destined for the gateway would not be forwarded across the incorrect VLAN boundary, making the gateway unreachable.
- ✗
The Ethernet cable is a crossover cable.
Why it's wrong here
Modern network equipment, including switches and network interface cards (NICs), universally supports Auto-MDIX (Automatic Medium-Dependent Interface Crossover). This feature automatically detects the wiring configuration of an Ethernet cable, whether straight-through or crossover, and adjusts the internal transmit and receive pairs accordingly. Therefore, using a crossover cable to connect a workstation to a modern switch port would not impede network connectivity or prevent reaching the default gateway.
- ✗
The workstation's subnet mask is wrong.
Why it's wrong here
An incorrect subnet mask primarily impacts a workstation's ability to correctly determine if a destination IP address is on its local network segment or requires routing through the default gateway. For instance, if the mask is too restrictive, the workstation might incorrectly classify the gateway as remote, or if too broad, it might assume a remote host is local. While this can cause communication failures, the symptom of being unable to reach the gateway itself often points to a more fundamental Layer 2 or Layer 3 connectivity breakdown, rather than a miscalculation of local vs. remote scope.
Visual reference
Go deeper
Related to this question
Learn chapter
Network Configuration: IP, DNS, DHCP
Key term
VLAN
A VLAN (Virtual Local Area Network) is a logical grouping of network devices that behave as if they are on the same physical network segment, regardless of their actual physical location.
Key term
CAN
A CAN (Controller Area Network) is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other without a host computer.
About these practice questions
Courseiva writes every 220-1201 question from scratch — 972 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 →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1201 practice question is part of Courseiva's free CompTIA 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 220-1201 exam.