ANS-C01 Question 273
Single answerYou have deployed a multi-tier application in AWS with an Application Load Balancer (ALB) in front of a fleet of EC2 instances in a private subnet. Users report intermittent connectivity issues when accessing the application. To troubleshoot, you need to verify if the ALB can reach the EC2 instances in the private subnet. Which AWS tool would you use to perform this connectivity analysis?
- A
Reachability Analyzer
- B
VPC Flow Logs
- C
Route Analyzer in AWS Network Manager
- D
AWS Trusted Advisor
Show answer and explanation
Correct answer: A
Explanation
When diagnosing connectivity issues within a VPC, the Reachability Analyzer is the appropriate tool to determine if a source resource (in this case, the ALB) can communicate with a destination resource (the EC2 instances). It simulates network paths, checks routing, security groups, NACLs, and other network configurations to identify connectivity issues.
- A. Correct.
Reachability Analyzer is the correct tool for this use case because it allows you to analyze the connectivity between resources in your VPC. It can determine whether the ALB can communicate with the EC2 instances in the private subnet by simulating network paths.
- B. Incorrect.
VPC Flow Logs provide logs of network traffic in your VPC but do not directly analyze connectivity or determine if two resources can communicate.
- C. Incorrect.
Route Analyzer in AWS Network Manager is used for analyzing routes in a global network under AWS Network Manager. However, it does not perform a resource-to-resource connectivity analysis within a VPC.
- D. Incorrect.
AWS Trusted Advisor provides recommendations for cost optimization, security, and performance but does not include tools for connectivity analysis.