CCNA Network Infrastructure and Connectivity Practice Question
A user reports that they cannot access a remote server at IP address 10.10.20.50. The user's PC has IP address 192.168.1.25/24, and the default gateway is 192.168.1.1. The user can successfully ping the default gateway and other hosts on the local subnet. However, pings to 10.10.20.50 fail, and a traceroute shows only the first hop (192.168.1.1) followed by timeouts. Which of the following is the most likely cause?
⚠ Common exam trap
Cisco often tests the distinction between local connectivity issues (subnet mask, ARP) and routing issues (missing routes), trapping candidates who assume a failed ping to a remote IP must be due to the destination being down or a DNS problem.
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 default gateway lacks a route to the 10.10.20.0/24 network.
The user can reach local hosts and the default gateway, confirming that the PC's IP configuration and local switching are functional. The traceroute stopping at 192.168.1.1 with subsequent timeouts indicates that the default gateway receives the packets but does not know how to forward them to the 10.10.20.0/24 network. Therefore, the most likely cause is that the default gateway lacks a route to that remote 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 user's PC has an incorrect subnet mask.
Why it's wrong here
If the user's subnet mask were incorrect, the client's view of which addresses are local vs. remote would change. The fact that the PC can ping the default gateway proves the gateway's IP falls within the client's locally connected subnet; otherwise the ping would have to be sent to another gateway and would not succeed. Local host pings also succeeding confirms the mask is correct, so this option cannot explain a traceroute that stops immediately after the first hop.
- ✓
The default gateway lacks a route to the 10.10.20.0/24 network.
Why this is correct
Since the client can ping the gateway but traceroute fails immediately after the first hop, the gateway does not know how to forward packets to 10.10.20.0/24. It either drops the packets or returns an ICMP destination unreachable, causing the observed behavior.
- ✗
The remote server at 10.10.20.50 is powered off.
Why it's wrong here
If the server were down, intermediate routers between the gateway and the server would still respond to traceroute probes, showing a path before timeouts at the server. The trace only showing the gateway and then timeouts is inconsistent with a powered-off server.
- ✗
The user's DNS server is unreachable.
Why it's wrong here
DNS translates hostnames to IP addresses and is consulted only when a name such as www.example.com is used. Here the destination is given as the literal IP address 10.10.20.50, so ICMP echo requests and traceroute probes are sent without any DNS query. An unreachable DNS server would stop name resolution and could produce 'unknown host' errors for hostnames, but it does not affect connectivity tests or packet forwarding to a directly addressed IP, so it is not the cause.
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.
✓The default gateway lacks a route to the 10.10.20.0/24 network.Correct answer▾
Why this is correct
Since the client can ping the gateway but traceroute fails immediately after the first hop, the gateway does not know how to forward packets to 10.10.20.0/24. It either drops the packets or returns an ICMP destination unreachable, causing the observed behavior.
✗The user's PC has an incorrect subnet mask.Wrong answer — click to see why▾
Why this is wrong here
The user can communicate with the default gateway and other local devices, so the subnet mask is correctly configured for the local network.
✗The remote server at 10.10.20.50 is powered off.Wrong answer — click to see why▾
Why this is wrong here
A powered-off server would cause timeouts only after the last router before the server, not immediately after the first hop.
✗The user's DNS server is unreachable.Wrong answer — click to see why▾
Why this is wrong here
Because the user is using the server's IP address, DNS is not involved in this connectivity test.
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
Go deeper
Related to this question
Learn chapter
IPv4 Addressing and Address Classes
Key term
Default gateway
A default gateway is a network device, typically a router, that acts as the exit point for traffic from a local network to other networks, including the internet.
Key term
Subnet
A subnet is a logical subdivision of an IP network, created by partitioning a larger network address space using subnet masks.
About these practice questions
Courseiva writes every 200-301 question from scratch — 1,389 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 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.