The answer is a missing default route on the Layer 3 switch, not the 'no ip proxy-arp' configuration. The SVI for VLAN 10 is correctly assigned the IP address 192.168.10.1, and it will always respond to ARP requests for that address regardless of the proxy-arp setting, so the user’s PC can reach its default gateway. However, without a default route pointing toward the next-hop router (198.51.100.1), the switch has no path to forward traffic destined for the internet (203.0.113.1), causing the connectivity failure. On the CCNA 200-301 v2 exam, this scenario tests your understanding of Layer 3 switching and routing fundamentals, often appearing as a trap where candidates mistakenly blame proxy-ARP for an SVI’s own ARP behavior. The key insight is that an SVI’s IP address is always reachable via ARP locally; the real issue is the absence of a route to external networks. Memory tip: “Proxy-ARP is for others, not for your own SVI—check the route table first.”
CCNA Network Infrastructure and Connectivity Practice Question
This 200-301 practice question tests your understanding of network infrastructure and connectivity. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Network Topology
You are connected to the console of switch SW1. A user on VLAN 10 reports they cannot reach the internet (203.0.113.1). The switch is configured as a Layer 3 switch with SVIs. Identify and correct the misconfiguration that prevents the user's default gateway from functioning. The user's PC has IP address 192.168.10.50/24 and uses 192.168.10.1 as its default gateway.
SW1# show running-config | section interface Vlan10
interface Vlan10
ip address 192.168.10.1 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
!
SW1# show ip interface brief
Interface IP-Address OK? Method Status Protocol
Vlan1 unassigned YES unset administratively down down
Vlan10 192.168.10.1 YES manual up up
GigabitEthernet0/0 unassigned YES unset up up
GigabitEthernet0/1 unassigned YES unset up up
GigabitEthernet0/2 unassigned YES unset up up
SW1# show ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.10.0/24 is directly connected, Vlan10
L 192.168.10.1/32 is directly connected, Vlan10
SW1#
A
The SVI for VLAN 10 has 'no ip proxy-arp' configured, and there is no default route on the switch.
This is correct because the switch needs proxy ARP enabled on the SVI to respond to ARP requests for the default gateway IP when the gateway is not directly connected. Additionally, a default route is required to forward traffic destined for the internet (203.0.113.1) to the next-hop router.
B
The SVI for VLAN 10 has the wrong IP address configured; it should be 192.168.10.254 instead of 192.168.10.1.
Why wrong: This is incorrect because the user's default gateway is 192.168.10.1, so the SVI must have that IP address. Changing it to 192.168.10.254 would break connectivity even further.
C
The switch has a default route pointing to 203.0.113.1, but the SVI for VLAN 10 is missing the 'ip helper-address' command.
Why wrong: This is incorrect because 'ip helper-address' is used for DHCP relay, not for default gateway functionality. The issue is that the switch cannot route traffic to the internet without a proper default route, and proxy ARP may be disabled.
D
The VLAN 10 interface is administratively down, and the switch needs to be reloaded to apply the configuration.
Why wrong: This is incorrect because the question implies the user can reach other devices on VLAN 10 (since the issue is only internet access), so the SVI is likely up. Reloading the switch is unnecessary and would not fix a missing default route or proxy ARP issue.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The SVI for VLAN 10 has 'no ip proxy-arp' configured, and there is no default route on the switch.
The switch's SVI for VLAN 10 has the correct IP address (192.168.10.1) and will always respond to ARP requests for that address regardless of the proxy‑arp setting. The real problem is the absence of a default route, so the switch cannot forward traffic destined for the Internet (203.0.113.1). Option A correctly points to the missing default route as the root cause; the 'no ip proxy-arp' line is present but irrelevant to the SVI's own ARP behavior. The solution is to configure a default route toward the next‑hop router (198.51.100.1).
Key principle: A trunk being up does not mean the VLAN is allowed across it. Always verify the allowed VLAN list and whether the VLAN exists on both switches.
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 SVI for VLAN 10 has 'no ip proxy-arp' configured, and there is no default route on the switch.
Why this is correct
This is correct because the switch needs proxy ARP enabled on the SVI to respond to ARP requests for the default gateway IP when the gateway is not directly connected. Additionally, a default route is required to forward traffic destined for the internet (203.0.113.1) to the next-hop router.
Related concept
Access ports place end devices into a single VLAN.
✗
The SVI for VLAN 10 has the wrong IP address configured; it should be 192.168.10.254 instead of 192.168.10.1.
Why it's wrong here
This is incorrect because the user's default gateway is 192.168.10.1, so the SVI must have that IP address. Changing it to 192.168.10.254 would break connectivity even further.
✗
The switch has a default route pointing to 203.0.113.1, but the SVI for VLAN 10 is missing the 'ip helper-address' command.
Why it's wrong here
This is incorrect because 'ip helper-address' is used for DHCP relay, not for default gateway functionality. The issue is that the switch cannot route traffic to the internet without a proper default route, and proxy ARP may be disabled.
✗
The VLAN 10 interface is administratively down, and the switch needs to be reloaded to apply the configuration.
Why it's wrong here
This is incorrect because the question implies the user can reach other devices on VLAN 10 (since the issue is only internet access), so the SVI is likely up. Reloading the switch is unnecessary and would not fix a missing default route or proxy ARP issue.
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 SVI for VLAN 10 has 'no ip proxy-arp' configured, and there is no default route on the switch.Correct answer▾
Why this is correct
This is correct because the switch needs proxy ARP enabled on the SVI to respond to ARP requests for the default gateway IP when the gateway is not directly connected. Additionally, a default route is required to forward traffic destined for the internet (203.0.113.1) to the next-hop router.
✗The SVI for VLAN 10 has the wrong IP address configured; it should be 192.168.10.254 instead of 192.168.10.1.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that the SVI IP must match the default gateway configured on the client; changing it to a different address would not fix the issue.
Why candidates choose this
Candidates might think the gateway IP is wrong because they assume a different subnet or a common gateway like .254, but the question states the user's gateway is .1.
✗The switch has a default route pointing to 203.0.113.1, but the SVI for VLAN 10 is missing the 'ip helper-address' command.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is confusing DHCP relay with routing; 'ip helper-address' does not affect the default gateway's ability to forward traffic.
Why candidates choose this
Candidates may associate 'ip helper-address' with connectivity issues, but it is only relevant for DHCP broadcasts across subnets.
✗The VLAN 10 interface is administratively down, and the switch needs to be reloaded to apply the configuration.Wrong answer — click to see why▾
Why this is wrong here
The specific factual error is that an administratively down interface would cause complete loss of connectivity, not just internet access, and reloading is not a standard troubleshooting step for configuration issues.
Why candidates choose this
Candidates might think the interface is down if they see no output from 'show ip interface brief', but the scenario indicates partial connectivity, ruling out a down interface.
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?”
Common exam traps
Common exam trap: an active trunk can still block the VLAN you need
A trunk being up does not prove every VLAN is crossing it. Check allowed VLAN lists, native VLAN mismatch, VLAN existence and access-port assignment.
Detailed technical explanation
How to think about this question
VLAN questions usually combine access-port and trunking clues. The key is to identify whether the issue is local to one switchport, caused by the trunk, or caused by the VLAN not existing where it needs to exist.
KKey Concepts to Remember
Access ports place end devices into a single VLAN.
Trunk ports carry multiple VLANs between switches.
Allowed VLAN lists decide which VLANs can cross a trunk.
Native VLAN mismatch can create confusing symptoms.
TExam Day Tips
→Use show vlan brief to verify access VLANs.
→Use show interfaces trunk to verify trunk state and allowed VLANs.
→Do not treat every same-VLAN issue as a routing problem.
Key takeaway
A trunk being up does not mean the VLAN is allowed across it. Always verify the allowed VLAN list and whether the VLAN exists on both switches.
Real-world example
How this comes up in practice
A help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 200-301 question in full detail.
Review VLAN allowed lists, native VLAN mismatch detection, and how to verify VLAN membership with show vlan brief and show interfaces trunk. Then practise related 200-301 questions on switching, trunking, and access-port configuration.
Network Infrastructure and Connectivity — This question tests Network Infrastructure and Connectivity — Access ports place end devices into a single VLAN..
What is the correct answer to this question?
The correct answer is: The SVI for VLAN 10 has 'no ip proxy-arp' configured, and there is no default route on the switch. — The switch's SVI for VLAN 10 has the correct IP address (192.168.10.1) and will always respond to ARP requests for that address regardless of the proxy‑arp setting. The real problem is the absence of a default route, so the switch cannot forward traffic destined for the Internet (203.0.113.1). Option A correctly points to the missing default route as the root cause; the 'no ip proxy-arp' line is present but irrelevant to the SVI's own ARP behavior. The solution is to configure a default route toward the next‑hop router (198.51.100.1).
What should I do if I get this 200-301 question wrong?
Review VLAN allowed lists, native VLAN mismatch detection, and how to verify VLAN membership with show vlan brief and show interfaces trunk. Then practise related 200-301 questions on switching, trunking, and access-port configuration.
What is the key concept behind this question?
Access ports place end devices into a single VLAN.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.