PAS-C01 Operations and Maintenance Practice Question
An operations team manages an SAP ERP system on AWS that uses a single EC2 instance for the SAP central services (SCS) and multiple instances for application servers. The system is running in a VPC with both public and private subnets. The team notices that the SCS instance is unreachable from the application servers after a maintenance window where network ACLs were updated. The application servers are in private subnets, and the SCS instance is in a public subnet. The team has verified that the security groups allow the required traffic. Which step should the team take to resolve the connectivity issue?
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 network ACL rules for both the public and private subnets.
The issue is that after maintenance, network ACLs were updated, causing connectivity loss between the SCS instance (public subnet) and application servers (private subnets). Network ACLs are stateless and control traffic at the subnet level. Since security groups are already verified, the likely cause is the NACL rules. Option A is correct because reviewing NACL rules for both subnets will identify missing inbound/outbound rules. Option B is incorrect because route tables to the internet gateway affect internet-bound traffic, not internal VPC traffic. Option C is incorrect because Elastic IPs are for internet access, not internal connectivity. Option D is incorrect because security groups were confirmed to allow traffic, so the issue is at the NACL level.
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 network ACL rules for both the public and private subnets.
Why this is correct
Network ACLs can block traffic if misconfigured.
- ✗
Verify that the route tables have a route to the internet gateway.
Why it's wrong here
Route tables are for subnet routing, not direct connectivity between instances in the same VPC.
- ✗
Assign an Elastic IP to the SCS instance.
Why it's wrong here
Elastic IPs are for internet connectivity, not internal communication.
- ✗
Check the security group rules on the application servers.
Why it's wrong here
Security groups have already been verified.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PAS-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 PAS-C01 exam.