ANS-C01 Question 274
Select 3A company is troubleshooting connectivity issues between an Amazon EC2 instance in a private subnet and an on-premises server over a VPN connection. Despite configuring the VPN and route tables correctly, the EC2 instance cannot reach the on-premises server. Which AWS tool(s) can be used to diagnose and pinpoint the issue?
- A
Reachability Analyzer to verify the network path between the EC2 instance and the on-premises server
- B
VPC Flow Logs to capture information about the traffic reaching the private subnet
- C
CloudTrail to analyze API activity and changes to the VPN configuration
- D
Route Analyzer to identify potential issues in the routing configuration
- E
AWS Trusted Advisor to check for misconfigured security groups and access controls
Show answer and explanation
Correct answers: A, B, D
Explanation
To diagnose connectivity issues between an EC2 instance and an on-premises server, it is essential to use tools that specifically address network path verification, traffic analysis, and routing configuration. Reachability Analyzer, VPC Flow Logs, and Route Analyzer each provide insights into different aspects of connectivity, making them the most suitable tools for this scenario. CloudTrail and Trusted Advisor, while useful for other purposes, are not designed for in-depth network troubleshooting.
- A. Correct.
Reachability Analyzer is a powerful tool for analyzing and verifying network paths between resources, such as an EC2 instance and an on-premises server. It helps identify any misconfigured security groups, NACLs, or route tables.
- B. Correct.
VPC Flow Logs can provide detailed information about the traffic entering and exiting the private subnet. This can help identify if traffic is being dropped or not reaching its destination.
- C. Incorrect.
While CloudTrail is useful for tracking API activity and configuration changes, it does not directly diagnose connectivity issues or analyze traffic flow.
- D. Correct.
Route Analyzer can be used to identify issues in the routing configuration, such as missing or incorrect routes in the route table. This is critical when diagnosing connectivity problems.
- E. Incorrect.
AWS Trusted Advisor provides general best practices and recommendations but does not specifically diagnose network connectivity issues.