Quick Answer
The answer is a firewall blocking external traffic. This is the most likely cause because a firewall enforces security rules that control inbound and outbound network traffic; when a printer works locally but is inaccessible from outside the network, the firewall is typically configured to block unsolicited incoming connections from external subnets, preventing remote devices from reaching the printer’s IP address or port. On the CompTIA ITF+ FC0-U61 exam, this scenario tests your understanding of basic network security concepts and how firewalls segment internal and external traffic—a common trap is confusing this with a driver or IP address conflict, but remember that local communication rules out those issues. A simple memory tip: if it talks inside but not outside, the firewall is the guide.
This FC0-U61 practice question tests your understanding of it concepts and terminology. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A technician installs a new network printer. It can communicate with other computers on the same network but no one outside the network can access it. What is the MOST likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Firewall blocking external traffic
A firewall often blocks inbound connections from the internet to internal devices.
Incorrect printer driver
Why wrong: A driver issue affects print jobs, not network connectivity.
No IP address configured
Why wrong: Without an IP address, the printer would not communicate locally either.
Faulty Ethernet cable
Why wrong: A faulty cable would prevent local communication as well.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Firewall blocking external traffic
A firewall is designed to control incoming and outgoing network traffic based on predetermined security rules. If the printer can communicate locally but not with external networks, the most likely cause is that the firewall is blocking inbound traffic from outside the local subnet, preventing external devices from reaching the printer's IP address or port.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Firewall blocking external traffic
Why this is correct
A firewall often blocks inbound connections from the internet to internal devices.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
Incorrect printer driver
Why it's wrong here
A driver issue affects print jobs, not network connectivity.
No IP address configured
Why it's wrong here
Without an IP address, the printer would not communicate locally either.
Faulty Ethernet cable
Why it's wrong here
A faulty cable would prevent local communication as well.
Common exam traps
The trap here is that candidates may confuse a firewall blocking external traffic with a network connectivity issue, such as a faulty cable or missing IP address, but the key clue is that local communication works fine, isolating the problem to external access control.
Detailed technical explanation
Firewalls typically operate at the network layer (Layer 3) and transport layer (Layer 4), filtering traffic based on source/destination IP addresses and port numbers. In a typical office network, the firewall might allow internal subnet traffic (e.g., 192.168.1.0/24) while blocking unsolicited inbound traffic from the internet, which would prevent external hosts from initiating connections to the printer's IP. A common real-world scenario is a printer that works for local users but cannot be accessed via remote printing or cloud services due to a missing firewall rule allowing inbound traffic on ports like 9100 (raw printing) or 515 (LPD).
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
What to study next
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FAQ
IT Concepts and Terminology — This question tests IT Concepts and Terminology — Read the scenario before looking for a memorised answer..
The correct answer is: Firewall blocking external traffic — A firewall is designed to control incoming and outgoing network traffic based on predetermined security rules. If the printer can communicate locally but not with external networks, the most likely cause is that the firewall is blocking inbound traffic from outside the local subnet, preventing external devices from reaching the printer's IP address or port.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 25, 2026
This FC0-U61 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 FC0-U61 exam.
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