CCNA Network Services and Security Practice Question
Exhibit
C:\Users\User1> nslookup intranet.company.local Server: dc01.company.local Address: 192.168.10.10 *** dc01.company.local can't find intranet.company.local: Non-existent domain C:\Users\User1> nslookup mail.company.local Server: dc01.company.local Address: 192.168.10.10 Name: mail.company.local Address: 192.168.10.55 C:\Users\User1> nslookup 192.168.10.50 Server: dc01.company.local Address: 192.168.10.10 Name: webserver.company.local Address: 192.168.10.50
A user reports that they cannot access the company's internal web server at 'intranet.company.local' from their workstation. The workstation can ping the web server's IP address 192.168.10.50 successfully, and other internal services like email (mail.company.local) are reachable. Which DNS record issue is most likely causing this problem?
⚠ Common exam trap
Cisco often tests the distinction between forward DNS records (A/AAAA) and reverse DNS records (PTR), and candidates mistakenly choose PTR when the symptom is a forward resolution failure, confusing the direction of the lookup.
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
✓
Add an A record mapping 'intranet.company.local' to IP address 192.168.10.50
The workstation can ping the web server's IP address (192.168.10.50), confirming network connectivity and that the server is online. However, the user cannot access the server by its hostname 'intranet.company.local', which indicates a DNS resolution failure. Since other internal services like email are reachable, the DNS zone is functioning, but there is no A record that maps the hostname 'intranet' to its IP address. Adding an A record for 'intranet.company.local' pointing to 192.168.10.50 will resolve the issue.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Add a CNAME record that aliases 'intranet.company.local' to 'webserver.company.local'
Why it's wrong here
A CNAME record could work if an existing A record for 'webserver.company.local' exists, but the issue is that no A record exists for 'intranet.company.local' at all. Adding a CNAME without an underlying A record would still result in a non-existent domain error.
- ✓
Add an A record mapping 'intranet.company.local' to IP address 192.168.10.50
Why this is correct
The nslookup output confirms that a forward lookup for 'intranet.company.local' returns no A record, even though the target IP 192.168.10.50 is reachable on the network. Creating an A record in the company.local DNS zone maps the hostname to that IP address, allowing clients to resolve the name to the correct destination. Because the IP is already valid and no CNAME or other record exists, a direct A record is the minimal, correct fix.
- ✗
Verify the PTR record for 192.168.10.50 points to 'intranet.company.local'
Why it's wrong here
The PTR record is used for reverse lookups (IP to name), which is not the issue here. The forward lookup (name to IP) is failing, so modifying the PTR record would not resolve the problem.
- ✗
Check the NS records for the 'company.local' zone to ensure proper delegation
Why it's wrong here
NS records define authoritative name servers for a zone. Since other hostnames like 'mail.company.local' resolve correctly, the zone is properly delegated and the NS records are functioning. The problem is specific to one missing record.
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 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓Add an A record mapping 'intranet.company.local' to IP address 192.168.10.50Correct answer▾
Why this is correct
The nslookup output confirms that a forward lookup for 'intranet.company.local' returns no A record, even though the target IP 192.168.10.50 is reachable on the network. Creating an A record in the company.local DNS zone maps the hostname to that IP address, allowing clients to resolve the name to the correct destination. Because the IP is already valid and no CNAME or other record exists, a direct A record is the minimal, correct fix.
✗Add a CNAME record that aliases 'intranet.company.local' to 'webserver.company.local'Wrong answer — click to see why▾
Why this is wrong here
The root cause is a missing A record; a CNAME record would not resolve without an A record for the target.
✗Verify the PTR record for 192.168.10.50 points to 'intranet.company.local'Wrong answer — click to see why▾
Why this is wrong here
PTR records are not used for forward name resolution; the issue is with the forward lookup zone.
✗Check the NS records for the 'company.local' zone to ensure proper delegationWrong answer — click to see why▾
Why this is wrong here
The zone delegation is working (other records resolve), so NS records are not the cause.
Analysis generated from the official 200-301blueprint 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
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
Diagnosing DNS Record Issues — A, AAAA, CNAME, MX, NS, and PTR Records
Key term
A record
An A record is a type of DNS resource record that maps a domain name to an IPv4 address.
Key term
Ping
Ping is a network utility used to test whether a remote computer or device is reachable across an IP network and to measure the round-trip time of data packets.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-301 practice question is part of Courseiva's free Cisco 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 200-301 exam.