Learn how AWS VPC Flow Logs capture inbound and outbound network traffic for Amazon EC2 instances. Understand its features, use cases, and benefits for network monitoring and troubleshooting.
Table of Contents
Question
Which AWS service or feature captures information about inbound and outbound network traffic from an Amazon EC2 instance?
A. VPC Reachability Analyzer
B. Amazon Athena
C. VPC Flow Logs
D. AWS X-Ray
Answer
C. VPC Flow Logs
Explanation
The correct answer is C because VPC Flow Logs are an AWS service or feature that capture information about inbound and outbound network traffic from an Amazon EC2 instance. VPC Flow Logs are a feature that enables customers to capture information about the IP traffic going to and from network interfaces in their VPCs. VPC Flow Logs can help customers monitor and troubleshoot connectivity issues, such as traffic that is not reaching an instance or traffic that is being rejected by a security group. The other options are incorrect because they are not AWS services or features that capture information about inbound and outbound network traffic from an Amazon EC2 instance. VPC Reachability Analyzer is an AWS service or feature that allows customers to perform connectivity testing between resources in their VPCs and identify configuration issues that prevent connectivity. Amazon Athena is an AWS service that allows customers to query data stored in Amazon S3 using standard SQL. AWS X-Ray is an AWS service that allows customers to analyze and debug distributed applications, such as those built using a microservices architecture.
The AWS service that captures information about inbound and outbound network traffic from an Amazon EC2 instance is VPC Flow Logs. This feature of Amazon Virtual Private Cloud (VPC) enables you to monitor IP traffic going to and from network interfaces within your VPC.
Here’s why VPC Flow Logs is the correct answer:
Purpose of VPC Flow Logs
VPC Flow Logs record metadata about the IP traffic (e.g., source/destination IPs, ports, protocols, and actions) traversing network interfaces in your VPC. They do not capture the actual content of the data but provide valuable insights for monitoring and troubleshooting network activity.
Use Cases
- Diagnosing overly restrictive security group or network ACL rules.
- Monitoring application traffic to detect anomalies or unauthorized access.
- Determining whether specific traffic is allowed or rejected by security policies.
Log Destinations
Flow log data can be sent to Amazon CloudWatch Logs, Amazon S3, or Amazon Kinesis Data Firehose for analysis and storage.
Configuration Scope
You can enable flow logs at different levels:
- Entire VPC
- Specific subnets
- Individual Elastic Network Interfaces (ENIs).
Advantages
- Non-intrusive: Flow logs operate outside the data path, ensuring no impact on network performance.
- Flexible: Logs can be customized to include specific fields relevant to your use case.
Why Other Options Are Incorrect
A. VPC Reachability Analyzer: This tool checks connectivity between resources in a VPC but does not log network traffic details.
B. Amazon Athena: Athena is a query service for analyzing data stored in Amazon S3 using SQL but is unrelated to capturing network traffic.
D. AWS X-Ray: X-Ray helps trace requests through applications but does not monitor or log EC2 network traffic.
Key Takeaway
For capturing detailed information about inbound and outbound traffic from an Amazon EC2 instance, use VPC Flow Logs. It is a powerful tool for enhancing visibility into your AWS networking environment while supporting security and operational troubleshooting needs.
Amazon AWS Certified Cloud Practitioner CLF-C02 certification exam practice question and answer (Q&A) dump with detail explanation and reference available free, helpful to pass the Amazon AWS Certified Cloud Practitioner CLF-C02 exam and earn Amazon AWS Certified Cloud Practitioner CLF-C02 certification.