220-1101 Networking Practice Question
A user reports that they can access internal company servers using IP addresses (e.g., 192.168.1.100) but cannot browse the internet. The user can ping the default gateway (192.168.1.1) successfully. Other users on the same subnet have full internet access. The technician checks the user's IP configuration and sees that the IP address, subnet mask, default gateway, and DNS server (192.168.1.10) are all correct. Which of the following is the MOST likely cause of the issue?
⚠ Common exam trap
A common mix-up: candidates assume DNS is the culprit when internet browsing fails, but the question explicitly states the DNS server is correct and other users have full access, shifting the focus to a client-side application-layer setting like the browser proxy.
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 user's browser proxy settings are configured to use an incorrect proxy server
Since the user can access internal servers by IP and successfully ping the default gateway, Layer 3 connectivity is intact. The inability to browse the internet while other users on the same subnet have full access points to a client-specific configuration issue. A misconfigured browser proxy setting (e.g., pointing to an incorrect or non-existent proxy server) would prevent HTTP/HTTPS traffic from reaching external destinations, even though DNS and IP routing are working correctly.
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 user's browser proxy settings are configured to use an incorrect proxy server
Why this is correct
An incorrect browser proxy configuration directs outbound HTTP/HTTPS requests to a proxy server that is unreachable or not designed for this client, so external websites time out. However, connections to internal servers by IP address are typically sent directly (bypassing the proxy) because the proxy is used for internet traffic or the internal addresses are excluded, explaining why the user still reaches internal resources. This is a client-side misconfiguration that does not affect network connectivity or IP routing.
- ✗
The DNS server is not resolving external domain names
Why it's wrong here
If the DNS server were failing to resolve external names, other users would also be affected. The user can ping the gateway, so DNS resolution for internal names works, but the issue is specific to internet browsing.
When this WOULD be correct
A user cannot access any websites by name but can access them by IP address, and other users on the same subnet have the same issue. The DNS server is misconfigured or unreachable, causing all external domain name resolutions to fail.
- ✗
The network cable is loose or faulty
Why it's wrong here
A loose or faulty network cable operates at Layer 1 and would manifest as link flaps, dropped packets, or total loss of connectivity. The user's ability to ping the gateway and access internal servers proves that the physical link is established and carrying frames successfully, since those operations require functioning Layer 1/2 connectivity. Cable problems cannot selectively block external DNS/HTTP while leaving internal IP communications intact.
When this WOULD be correct
A user reports no network connectivity at all (cannot ping any IP, no link light). Other users on the same subnet are fine. The technician checks the cable and finds it unplugged or damaged. In that scenario, a loose or faulty cable is the most likely cause.
- ✗
The user's IP address is in the wrong subnet
Why it's wrong here
If the user's IP address were in the wrong subnet, the host would have no valid route to the default gateway, making it impossible to ping the gateway or access any internal servers. The fact that the user can reach internal servers by IP indicates the IP, subnet mask, and gateway are within the same logical network segment. A subnet mismatch would be a global IP stack problem rather than an application-layer symptom like browser proxy failure.
When this WOULD be correct
A user cannot communicate with any devices on the network, including the default gateway, and an IP configuration check reveals an IP address that does not match the subnet mask (e.g., IP 192.168.1.100 with subnet mask 255.255.255.0 but gateway on a different subnet).
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 220-1101 exam frequently reuses these exact scenarios with slightly different constraints.
✓The user's browser proxy settings are configured to use an incorrect proxy serverCorrect answer▾
Why this is correct
An incorrect browser proxy configuration directs outbound HTTP/HTTPS requests to a proxy server that is unreachable or not designed for this client, so external websites time out. However, connections to internal servers by IP address are typically sent directly (bypassing the proxy) because the proxy is used for internet traffic or the internal addresses are excluded, explaining why the user still reaches internal resources. This is a client-side misconfiguration that does not affect network connectivity or IP routing.
✗The DNS server is not resolving external domain namesWrong answer — click to see why▾
Why this is wrong here
The DNS server is set correctly (192.168.1.10) and the user can access internal servers by IP, indicating DNS resolution is working for internal names. The issue is internet browsing, which points to a proxy misconfiguration, not DNS failure.
★ When this WOULD be the correct answer
A user cannot access any websites by name but can access them by IP address, and other users on the same subnet have the same issue. The DNS server is misconfigured or unreachable, causing all external domain name resolutions to fail.
Why candidates choose this
Candidates often associate internet browsing issues with DNS problems, overlooking that the user can access internal servers by IP and that DNS settings appear correct, leading them to assume DNS is the culprit.
✗The network cable is loose or faultyWrong answer — click to see why▾
Why this is wrong here
A loose or faulty network cable would prevent all network communication, including access to internal servers via IP addresses, which the user can still do. Since the user can ping the default gateway and access internal servers, the cable is functioning correctly.
★ When this WOULD be the correct answer
A user reports no network connectivity at all (cannot ping any IP, no link light). Other users on the same subnet are fine. The technician checks the cable and finds it unplugged or damaged. In that scenario, a loose or faulty cable is the most likely cause.
Why candidates choose this
Candidates may assume that any network issue is due to physical connectivity problems, especially when symptoms are vague. They overlook that partial connectivity (access to internal IPs) rules out a cable fault.
✗The user's IP address is in the wrong subnetWrong answer — click to see why▾
Why this is wrong here
The user can access internal servers via IP and ping the gateway, indicating correct subnet configuration. A wrong subnet would prevent all IP communication, not just internet browsing.
★ When this WOULD be the correct answer
A user cannot communicate with any devices on the network, including the default gateway, and an IP configuration check reveals an IP address that does not match the subnet mask (e.g., IP 192.168.1.100 with subnet mask 255.255.255.0 but gateway on a different subnet).
Why candidates choose this
Candidates may confuse symptoms of DNS failure with subnet mismatch, or incorrectly assume that internet access issues always stem from IP configuration errors.
Analysis generated from the official 220-1101blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
Quick reference
IPv4 Address Class Summary
| Class | First Octet Range | Default Mask | Networks | Hosts per Network |
|---|---|---|---|---|
| A | 1–126 | /8 (255.0.0.0) | 126 | 16,777,214 |
| B | 128–191 | /16 (255.255.0.0) | 16,384 | 65,534 |
| C | 192–223 | /24 (255.255.255.0) | 2,097,152 | 254 |
| D | 224–239 | N/A | Multicast groups | — |
| E | 240–255 | N/A | Reserved / experimental | — |
127.x.x.x is reserved for loopback. Modern networks use CIDR (classless) rather than classful addressing.
Go deeper
Related to this question
Learn chapter
Default Gateway Configuration
Key term
Fully Qualified Domain Name
A Fully Qualified Domain Name is the complete and unambiguous website or server name that includes the host, domain, and top-level domain, leaving no room for guesswork.
Key term
Hypertext Transfer Protocol Secure
Hypertext Transfer Protocol Secure, or HTTPS, is the secure version of HTTP that encrypts data between a web browser and a website using SSL/TLS to protect sensitive information like passwords and credit card numbers.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1101 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 220-1101 exam.