AWS Certified Advanced Networking – Specialty (ANS-C01) — Question 78

A company has a global network and is using transit gateways to connect AWS Regions together. The company finds that two Amazon EC2 instances in different Regions are unable to communicate with each other. A network engineer needs to troubleshoot this connectivity issue.

What should the network engineer do to meet this requirement?

Answer options

• A. Use AWS Network Manager Route Analyzer to analyze routes in the transit gateway route tables and in the VPC route tables. Use VPC flow logs to analyze the IP traffic that security group rules and network ACL rules accept or reject in the VPC.
• B. Use AWS Network Manager Route Analyzer to analyze routes in the transit gateway route tables. Verify that the VPC route tables are correct. Use AWS Firewall Manager to analyze the IP traffic that security group rules and network ACL rules accept or reject in the VPC.
• C. Use AWS Network Manager Route Analyzer to analyze routes in the transit gateway route tables. Verify that the VPC route tables are correct. Use VPC flow logs to analyze the IP traffic that security group rules and network ACL rules accept or reject in the VPC.
• D. Use VPC Reachability Analyzer to analyze routes in the transit gateway route tables. Verify that the VPC route tables are correct. Use VPC flow logs to analyze the IP traffic that security group rules and network ACL rules accept or reject in the VPC.

Correct answer: C

Explanation

The correct answer is C because it combines the use of AWS Network Manager Route Analyzer to check the transit gateway and VPC route tables, as well as VPC flow logs to analyze traffic based on security group and network ACL rules. Option A is incorrect as it does not mention verifying the correctness of the VPC route tables. Option B is wrong since it suggests using AWS Firewall Manager instead of VPC flow logs, which are essential for analyzing traffic. Option D incorrectly recommends VPC Reachability Analyzer instead of AWS Network Manager Route Analyzer for this scenario.