ANS-C01 Network Management and Operations Practice Question
A network engineer is diagnosing a connectivity issue between an on-premises network and an Amazon VPC connected via a site-to-site VPN. The VPN tunnel is up, but traffic is not reaching the VPC. Which TWO actions should the engineer take to troubleshoot the issue? (Choose two.)
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
✓
Review the security group rules associated with the VPC resources to ensure they allow traffic from the on-premises network
Security groups act as a virtual firewall for VPC resources. If traffic from the on-premises network is not reaching the VPC, the security group rules must allow inbound traffic from the on-premises IP range. Option C is correct because the VPC route tables need a route for the on-premises network pointing to the virtual private gateway (VGW) to direct traffic correctly. Option B is incorrect because the customer gateway is the on-premises VPN endpoint, and its association with the VPC is already established since the VPN tunnel is up. Option D is incorrect because NAT is not a requirement for site-to-site VPN; the issue is about routing, not address translation. Option E is incorrect because the tunnel is already up, so checking its status again does not help diagnose why traffic is not flowing.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Review the security group rules associated with the VPC resources to ensure they allow traffic from the on-premises network
Why this is correct
Security groups act as a firewall for the instances.
- ✗
Confirm the customer gateway is associated with the correct VPC
Why it's wrong here
Customer gateway is associated with the VPN connection, not the VPC directly.
- ✓
Verify that the VPC route tables include routes for the on-premises network pointing to the virtual private gateway
Why this is correct
Without proper routes, traffic cannot be forwarded to the VPC.
- ✗
Verify that the on-premises network has a NAT device configured
Why it's wrong here
NAT is not required for site-to-site VPN connectivity.
- ✗
Check that the VPN tunnel's status is 'UP'
Why it's wrong here
The tunnel is already up.
Visual reference
Go deeper
Related to this question
About these practice questions
This ANS-C01 question is part of Courseiva's 1,621-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on ANS-C01
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A network engineer is troubleshooting a Site-to-Site VPN connection between an on-premises network and AWS. The VPN tunnel is up, but traffic is not flowing from the on-premises network to a VPC. The VPC has a virtual private gateway attached, and the route table has a route pointing to the virtual private gateway for the on-premises CIDR (192.168.0.0/16). The on-premises firewall shows that traffic is being sent to the VPN tunnel. What should the engineer check next?
easy- A.Verify that the virtual private gateway is attached to the VPC.
- ✓ B.Verify that the on-premises route table has a route to the VPC CIDR via the VPN tunnel.
- C.Verify that the on-premises firewall is not blocking UDP port 500 for IKE.
- D.Verify that the VPN tunnel's pre-shared key matches on both sides.
Why B: Since the VPN tunnel is up and the on-premises firewall confirms traffic is being sent to the tunnel, the issue is likely on the on-premises routing side. For traffic to flow from on-premises to the VPC, the on-premises router must have a route pointing to the VPC CIDR via the VPN tunnel interface. Without this route, packets will not be forwarded into the tunnel, even though the tunnel itself is operational.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This ANS-C01 practice question is part of Courseiva's free Amazon Web Services 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 ANS-C01 exam.