220-1101 Networking Practice Question
A user in a small office reports that they can access websites on the internet but cannot connect to the company's internal file server using its hostname (\\fileserver). Other users in the same office can access the file server by hostname without any issues. The technician runs ipconfig /all on the affected workstation and sees the following: IPv4 Address: 192.168.1.45, Subnet Mask: 255.255.255.0, Default Gateway: 192.168.1.1, DNS Server: 8.8.8.8. Which of the following is the MOST likely cause of the issue?
⚠ Common exam trap
CompTIA often tests the distinction between external and internal DNS servers, and the trap here is that candidates see internet access working and assume DNS is fine, overlooking that internal hostname resolution requires a DNS server that holds the internal zone records.
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 workstation is using an external DNS server instead of the internal DNS server.
The workstation can access the internet (via 8.8.8.8) but cannot resolve the internal hostname 'fileserver' because it is using an external DNS server (Google's 8.8.8.8) instead of the internal DNS server that holds the private DNS records for the company's local resources. Internal DNS servers typically host A or CNAME records for internal hostnames, which public DNS servers like 8.8.8.8 do not contain. This mismatch prevents hostname resolution for the file server while leaving internet access functional.
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 workstation's subnet mask is incorrect.
Why it's wrong here
The subnet mask 255.255.255.0 is correct for a /24 network (192.168.1.0/24). An incorrect subnet mask would prevent proper communication, but the user can access the internet and presumably other local resources, so this is not the issue.
- ✓
The workstation is using an external DNS server instead of the internal DNS server.
Why this is correct
The DNS server is set to 8.8.8.8 (Google's public DNS), which does not have records for the internal file server's hostname. The workstation can resolve external names but not internal ones. Other users likely use the internal DNS server (e.g., 192.168.1.5) which can resolve internal hostnames.
- ✗
The default gateway is misconfigured.
Why it's wrong here
A misconfigured default gateway would disrupt the workstation's ability to route packets to remote networks, yet the user can successfully access external websites, proving that the gateway 192.168.1.1 is functioning correctly for internet-bound traffic. Furthermore, the default gateway handles Layer 3 routing, not name resolution, so it cannot be the cause of the internal hostname resolution failure. The reported symptom is entirely consistent with a DNS problem, not a routing problem.
- ✗
The DHCP scope is exhausted.
Why it's wrong here
If the DHCP scope were exhausted, the workstation would have failed to obtain a valid IPv4 lease and would have automatically assigned itself an APIPA address (169.254.x.x), which cannot reach the internet or other subnets. However, the workstation holds a valid 192.168.1.x IP address and can access external websites, proving that a lease was successfully obtained. Additionally, scope exhaustion would typically affect multiple users simultaneously, whereas this issue is isolated to a single workstation. Thus, DHCP scope exhaustion is not the cause.
Visual reference
Quick reference
Common DNS Record Types
| Record | Purpose | Example |
|---|---|---|
| A | IPv4 address mapping | example.com → 93.184.216.34 |
| AAAA | IPv6 address mapping | example.com → 2606:2800::1 |
| CNAME | Alias to another hostname | www → example.com |
| MX | Mail server for domain | example.com → mail.example.com (priority 10) |
| TXT | Text data (SPF, DKIM, verification) | v=spf1 include:_spf.example.com ~all |
| NS | Authoritative name servers | example.com NS ns1.example.com |
| PTR | Reverse DNS (IP → hostname) | 34.216.184.93.in-addr.arpa → example.com |
| SOA | Zone authority record | Primary NS, admin email, serial, TTL defaults |
Go deeper
Related to this question
Learn chapter
Network Command Tools: ping, ipconfig, nslookup, tracert
Key term
Internet Protocol
Internet Protocol (IP) is the set of rules that governs how data is addressed, routed, and sent from one device to another across networks, including the internet.
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.
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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.