N10-009 Network Troubleshooting Practice Question
A network technician is troubleshooting intermittent internet access for a single user. The user’s workstation can ping the default gateway consistently, but web pages fail to load intermittently. Which of the following should the technician check NEXT?
⚠ Common exam trap
The N10-009 exam often tests the distinction between Layer 3 reachability (ping success) and application-layer failures (web browsing), leading candidates to incorrectly focus on DHCP or switch port settings instead of DNS.
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
✓
A) DNS server configuration
The user can ping the default gateway consistently, indicating Layer 3 connectivity to the local network is intact. However, intermittent web page failures suggest a name resolution issue, as DNS translates domain names to IP addresses. If the DNS server is misconfigured, unreachable, or returning stale records, the browser will fail to load pages even though basic IP connectivity works. Checking DNS server configuration is the logical next step because it directly addresses the symptom of name resolution failures.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
A) DNS server configuration
Why this is correct
If the configured DNS server is intermittently unavailable, overloaded, or providing inconsistent responses, name resolution requests for domain names will sometimes succeed and sometimes fail. This directly impacts web browsing, as browsers rely on DNS to translate URLs into IP addresses, leading to intermittent page loading issues. However, direct IP-based connectivity, such as pinging a known IP address or the default gateway, would remain unaffected, precisely matching the described symptoms.
- ✗
B) DHCP lease time
Why it's wrong here
An expired DHCP lease, if not successfully renewed, would typically cause the client to lose its assigned IP address, subnet mask, and gateway information. This fundamental loss of network configuration would result in a complete inability to communicate on the network, preventing even basic connectivity like pinging the local gateway. Therefore, it would manifest as a total network outage rather than just intermittent web browsing.
When this WOULD be correct
A technician is troubleshooting a user who cannot access network resources and receives an APIPA address. Checking DHCP lease time would be correct to see if the lease expired or the DHCP server is unreachable.
- ✗
C) Switch port speed and duplex settings
Why it's wrong here
Firewall rules specifically blocking ICMP traffic would prevent successful ping responses, which contradicts the scenario where underlying IP connectivity is implied to be functional. While a firewall could certainly block HTTP/HTTPS traffic, the success of ping operations indicates that the network path is open at the ICMP level. Intermittent web browsing points to a higher-layer service issue rather than a blanket block on a specific protocol like ICMP.
When this WOULD be correct
A technician is troubleshooting a user who experiences slow or intermittent network performance, and 'ping' shows packet loss or high latency. Checking switch port speed and duplex settings would be correct if a mismatch is suspected, such as a workstation set to 100/full connected to a switch port set to auto/auto.
- ✗
D) Firewall rules blocking ICMP
Why it's wrong here
A mismatch in speed or duplex settings between a network interface card and a switch port typically results in severe network performance degradation, high collision rates, or a complete loss of link connectivity. This would manifest as extremely slow or entirely non-functional network access for all traffic types, not just intermittent web browsing while basic IP-level pings remain successful. Such a physical layer issue would impact all network communications consistently.
When this WOULD be correct
A technician finds that a user cannot access any external websites, but internal resources work. Pinging external IPs fails while pinging internal IPs succeeds. In this scenario, checking firewall rules blocking ICMP or HTTP/S outbound would be appropriate.
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 N10-009 exam frequently reuses these exact scenarios with slightly different constraints.
✓A) DNS server configurationCorrect answer▾
Why this is correct
If the configured DNS server is intermittently unavailable, overloaded, or providing inconsistent responses, name resolution requests for domain names will sometimes succeed and sometimes fail. This directly impacts web browsing, as browsers rely on DNS to translate URLs into IP addresses, leading to intermittent page loading issues. However, direct IP-based connectivity, such as pinging a known IP address or the default gateway, would remain unaffected, precisely matching the described symptoms.
✗B) DHCP lease timeWrong answer — click to see why▾
Why this is wrong here
The user can ping the default gateway consistently, indicating DHCP lease is active and network connectivity is fine. Intermittent web page loading with successful pings points to a name resolution issue, not DHCP lease time.
★ When this WOULD be the correct answer
A technician is troubleshooting a user who cannot access network resources and receives an APIPA address. Checking DHCP lease time would be correct to see if the lease expired or the DHCP server is unreachable.
Why candidates choose this
Candidates may confuse DHCP lease expiration with intermittent connectivity, thinking a short lease could cause periodic disconnections, even though the user can consistently ping the gateway.
✗C) Switch port speed and duplex settingsWrong answer — click to see why▾
Why this is wrong here
The user can consistently ping the default gateway, indicating Layer 2 connectivity is fine. Intermittent web page loading with successful pings points to a name resolution issue, not duplex/speed mismatch, which would cause packet loss or complete connectivity failure.
★ When this WOULD be the correct answer
A technician is troubleshooting a user who experiences slow or intermittent network performance, and 'ping' shows packet loss or high latency. Checking switch port speed and duplex settings would be correct if a mismatch is suspected, such as a workstation set to 100/full connected to a switch port set to auto/auto.
Why candidates choose this
Candidates may confuse intermittent connectivity with physical layer issues, assuming duplex mismatch causes intermittent problems, but duplex mismatch typically causes constant errors or complete failure, not intermittent web access with stable pings.
✗D) Firewall rules blocking ICMPWrong answer — click to see why▾
Why this is wrong here
The user can ping the default gateway consistently, so ICMP traffic is not blocked. The issue is intermittent web page loading, which points to DNS resolution problems, not firewall rules.
★ When this WOULD be the correct answer
A technician finds that a user cannot access any external websites, but internal resources work. Pinging external IPs fails while pinging internal IPs succeeds. In this scenario, checking firewall rules blocking ICMP or HTTP/S outbound would be appropriate.
Why candidates choose this
Candidates may think firewall rules could intermittently block traffic, but the consistent ping success rules out ICMP blocking. They might confuse general connectivity issues with specific protocol filtering.
Analysis generated from the official N10-009blueprint 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
Troubleshooting Methodology
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.
Key term
Name Server
A name server is a specialized server that translates human-readable domain names into machine-readable IP addresses so that computers can find each other on a network.
About these practice questions
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This N10-009 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 N10-009 exam.