N10-009 Network Troubleshooting Practice Question
Users in a remote branch office report that they cannot access the company's cloud-based applications. The network administrator notices that the edge router's WAN interface is up but the branch's default route points to a next-hop IP that is unreachable. The administrator can ping the ISP's gateway IP from the router. What is the most likely cause?
⚠ Common exam trap
CompTIA often tests the distinction between a WAN interface being up and the default route's next-hop being reachable; candidates mistakenly assume that if the interface is up and the ISP gateway is pingable, the default route must be correct, but the next-hop IP configured in the static route could be a different, unreachable address.
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 static default route has an incorrect next-hop IP
The scenario describes a static default route configured with a next-hop IP that is unreachable. The WAN interface is up and the ISP gateway is reachable (as confirmed by the ping), but the router cannot forward traffic to the cloud because the static route points to an incorrect next-hop address. This is a classic static route misconfiguration where the next-hop IP does not match the ISP gateway or is not in the directly connected subnet.
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 routing protocol is not redistributing the default route
Why it's wrong here
"The routing protocol is not redistributing the default route" is not the primary issue here. Redistribution is a mechanism used by dynamic routing protocols (e.g., OSPF, EIGRP) to share routes learned from different sources or protocols across routing domains. The problem specifically refers to a *static default route* with an incorrect next-hop. Static routes are manually configured and do not inherently rely on dynamic routing protocols or redistribution for their basic functionality, although they *can* be redistributed. The fundamental problem lies in the static route's configuration itself, not in its propagation via a dynamic protocol.
When this WOULD be correct
In a scenario where OSPF or EIGRP is used and the default route is not being advertised into the routing domain, causing remote routers to lack a default route. For example, a router has a static default route but redistribution from static into OSPF is missing, so other routers don't learn it.
- ✓
The static default route has an incorrect next-hop IP
Why this is correct
If the next-hop IP in the static route is incorrect or the interface is down, traffic cannot be forwarded even though the WAN interface is up and the ISP gateway is reachable via another path.
- ✗
The WAN interface is administratively down
Why it's wrong here
"The WAN interface is administratively down" is incorrect because the problem statement explicitly indicates that the administrator has observed the WAN interface to be "up." An administratively down interface means it has been manually disabled, typically via a `shutdown` command, rendering it incapable of passing any traffic. If the interface were truly down, its status would reflect this, preventing any connectivity and directly contradicting the given information about its operational state.
When this WOULD be correct
A question where the edge router's WAN interface is down or disabled (e.g., 'interface status shows administratively down') and users cannot access remote resources, with no other routing issues mentioned.
- ✗
The firewall is blocking traffic to the cloud
Why it's wrong here
"The firewall is blocking traffic to the cloud" is an unlikely cause given the described symptom of a routing issue. If the static default route has an incorrect next-hop IP, packets destined for the cloud will fail to leave the local router or be forwarded to an incorrect destination *before* reaching any firewall that might be performing filtering. A firewall blocking issue typically means traffic successfully reaches the firewall but is then dropped based on policy, which is a subsequent step in the packet's journey after successful routing.
When this WOULD be correct
In a scenario where users cannot access cloud applications, the router has a valid default route, and pinging the ISP gateway succeeds, but traffic is still blocked, the firewall could be the cause if it is dropping traffic to the cloud IPs.
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.
✓The static default route has an incorrect next-hop IPCorrect answer▾
Why this is correct
If the next-hop IP in the static route is incorrect or the interface is down, traffic cannot be forwarded even though the WAN interface is up and the ISP gateway is reachable via another path.
✗The routing protocol is not redistributing the default routeWrong answer — click to see why▾
Why this is wrong here
The question states that the default route points to an unreachable next-hop IP, and the administrator can ping the ISP's gateway. This indicates a static route misconfiguration, not a redistribution issue. Redistribution would only matter if a dynamic routing protocol were involved, but the problem is with a static default route.
★ When this WOULD be the correct answer
In a scenario where OSPF or EIGRP is used and the default route is not being advertised into the routing domain, causing remote routers to lack a default route. For example, a router has a static default route but redistribution from static into OSPF is missing, so other routers don't learn it.
Why candidates choose this
Candidates may confuse a missing default route with a redistribution problem, especially if they've studied dynamic routing protocols. They might assume the default route should be learned via a routing protocol rather than being statically configured.
✗The WAN interface is administratively downWrong answer — click to see why▾
Why this is wrong here
The WAN interface is up (as stated), so it is not administratively down. An administratively down interface would show as 'down' or 'disabled', not 'up'.
★ When this WOULD be the correct answer
A question where the edge router's WAN interface is down or disabled (e.g., 'interface status shows administratively down') and users cannot access remote resources, with no other routing issues mentioned.
Why candidates choose this
Candidates may confuse 'interface up' with 'interface operational' and assume a down interface is the cause, or they may overlook the explicit statement that the interface is up.
✗The firewall is blocking traffic to the cloudWrong answer — click to see why▾
Why this is wrong here
The firewall blocking traffic to the cloud would not cause the router to have an unreachable next-hop IP for the default route; it would instead prevent traffic from passing through the firewall, but the router would still have a valid route.
★ When this WOULD be the correct answer
In a scenario where users cannot access cloud applications, the router has a valid default route, and pinging the ISP gateway succeeds, but traffic is still blocked, the firewall could be the cause if it is dropping traffic to the cloud IPs.
Why candidates choose this
Candidates may think that any connectivity issue to cloud applications must be due to a firewall blocking traffic, overlooking that the problem is actually a routing issue indicated by the unreachable next-hop.
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
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
Troubleshoot: Network Connectivity
Key term
Router
A router is a networking device that connects different networks together and directs data traffic between them by choosing the best path for data to travel.
Key term
CAN
A CAN (Controller Area Network) is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other without a host computer.
About these practice questions
Courseiva writes every N10-009 question from scratch — 464 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
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.