N10-009 Networking Concepts Practice Question
A workstation with IP address 10.0.1.5/24 needs to communicate with a server at 10.0.2.10/24. The workstation's default gateway is configured as 10.0.1.1. Which of the following will the workstation do with the IP packets destined for the server?
⚠ Common exam trap
The trap here is that candidates mistakenly think a host can ARP for any IP address, even across subnets, or that a host will drop traffic to a different subnet without a router, when in fact the host relies on its default gateway to reach remote networks.
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
✓
Send the packets to the default gateway.
The workstation's IP address (10.0.1.5/24) and the server's IP address (10.0.2.10/24) are on different subnets (10.0.1.0/24 vs. 10.0.2.0/24). When a host determines that the destination is not on the same local network, it will not attempt direct delivery via ARP. Instead, it forwards the IP packet to its configured default gateway (10.0.1.1), which then routes the packet toward the server's 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.
- ✗
Send the packets directly to the server using ARP.
Why it's wrong here
ARP (Address Resolution Protocol) is exclusively used to discover the Media Access Control (MAC) address of a device when its IP address is known, but only within the same local broadcast domain or subnet. Since the server is on a *different* network, the workstation cannot use ARP to directly resolve the server's MAC address. Instead, it must resolve the MAC address of its default gateway to forward the packet.
When this WOULD be correct
If both the workstation and server were on the same subnet (e.g., both 10.0.1.0/24), the workstation would use ARP to resolve the server's MAC address and send packets directly, without involving a gateway.
- ✓
Send the packets to the default gateway.
Why this is correct
The workstation first compares the destination IP address with its own IP address and subnet mask to determine if the destination is on the same local network segment. If the destination IP falls outside its local subnet, the workstation recognizes that it cannot directly deliver the packet. Consequently, it encapsulates the IP packet within an Ethernet frame addressed to its configured default gateway's MAC address, forwarding all traffic destined for remote networks to this gateway for subsequent routing.
- ✗
Send the packets to the DNS server for resolution.
Why it's wrong here
Sending packets to a DNS server for resolution is incorrect because DNS (Domain Name System) is specifically designed to translate human-readable domain names into numerical IP addresses. In this scenario, the question implies communication with a server, suggesting the destination IP address is either already known or will be resolved *before* the routing decision. DNS plays no role in the actual forwarding of an IP packet once the destination IP is established.
When this WOULD be correct
If the workstation needed to communicate with a server by its hostname (e.g., server.example.com) and did not have the IP address cached, it would send a DNS query to the DNS server to resolve the name before sending packets.
- ✗
Drop the packets because the server is on a different network.
Why it's wrong here
Dropping packets simply because the destination server is on a different network would prevent any communication beyond the local subnet, effectively isolating the workstation from the internet and other internal networks. Workstations are designed to attempt communication with remote hosts by forwarding packets to their default gateway, which is responsible for routing traffic between different subnets, rather than discarding them.
When this WOULD be correct
If the workstation had no default gateway configured, or if the destination network was unreachable (e.g., no route), the workstation would drop the packets. For example, a host with IP 10.0.1.5/24 trying to reach 10.0.2.10/24 with no gateway configured.
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.
✓Send the packets to the default gateway.Correct answer▾
Why this is correct
The workstation first compares the destination IP address with its own IP address and subnet mask to determine if the destination is on the same local network segment. If the destination IP falls outside its local subnet, the workstation recognizes that it cannot directly deliver the packet. Consequently, it encapsulates the IP packet within an Ethernet frame addressed to its configured default gateway's MAC address, forwarding all traffic destined for remote networks to this gateway for subsequent routing.
✗Send the packets directly to the server using ARP.Wrong answer — click to see why▾
Why this is wrong here
The workstation's IP (10.0.1.5/24) and server's IP (10.0.2.10/24) are on different subnets (10.0.1.0/24 vs 10.0.2.0/24). The workstation must send packets to its default gateway (10.0.1.1) for routing, not directly to the server via ARP.
★ When this WOULD be the correct answer
If both the workstation and server were on the same subnet (e.g., both 10.0.1.0/24), the workstation would use ARP to resolve the server's MAC address and send packets directly, without involving a gateway.
Why candidates choose this
Candidates may confuse ARP's role in local network communication with routing, assuming ARP can reach any IP regardless of subnet, or they may forget that ARP only works within the same broadcast domain.
✗Send the packets to the DNS server for resolution.Wrong answer — click to see why▾
Why this is wrong here
DNS resolution is used to translate domain names to IP addresses, but the workstation already knows the server's IP address (10.0.2.10). The question does not involve name resolution, so sending packets to the DNS server is irrelevant.
★ When this WOULD be the correct answer
If the workstation needed to communicate with a server by its hostname (e.g., server.example.com) and did not have the IP address cached, it would send a DNS query to the DNS server to resolve the name before sending packets.
Why candidates choose this
Candidates may confuse the steps of network communication, thinking that DNS is always involved before sending packets, even when the destination IP is already known.
✗Drop the packets because the server is on a different network.Wrong answer — click to see why▾
Why this is wrong here
The workstation will not drop the packets because it can send them to the default gateway (10.0.1.1), which will route them to the server on the different subnet (10.0.2.0/24).
★ When this WOULD be the correct answer
If the workstation had no default gateway configured, or if the destination network was unreachable (e.g., no route), the workstation would drop the packets. For example, a host with IP 10.0.1.5/24 trying to reach 10.0.2.10/24 with no gateway configured.
Why candidates choose this
Candidates may incorrectly assume that hosts cannot communicate across subnets without a router, forgetting that the default gateway provides that function.
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
Go deeper
Related to this question
Learn chapter
Network Virtualization and VXLAN
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
Packet
A packet is a small unit of data that is sent over a network, containing both the actual data and control information for delivery.
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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.