VPC Flow Logs
VPC Flow Logs is a feature that captures information about the IP traffic going to and from network interfaces in your VPC, providing visibility and insights into your network traffic across your VPC, subnets, and network interfaces. Flow log data can be used to monitor network traffic for security, compliance, and network troubleshooting purposes. Flow logs can be viewed and analyzed directly in the Amazon CloudWatch Logs service or exported to an Amazon S3 bucket for further analysis or long-term storage. VPC Flow Logs consist of various fields such as version, account ID, interface ID, source and destination IP addresses, source and destination ports, traffic action, and more.
Guide: Understanding Amazon VPC Flow Logs
Amazon VPC Flow Logs is a feature provided by AWS that enables users to capture and inspect network traffic in their VPC. This tool can be used for a variety of purposes, including troubleshooting connectivity issues, monitoring network performance, and detecting unusual traffic patterns that could indicate a security concern.
With VPC Flow Logs, you can track all the IP traffic (both inbound and outbound) going to and from network interfaces in your VPC. The logs are stored in CloudWatch by default, but can be published to S3 for more flexibility and cost efficiency.
To create a flow log, navigate to the 'VPC Dashboard' on AWS, go to 'Your VPCs', select a VPC, go to the 'Flow Logs' tab and click on 'Create Flow Log'. You can decide what level of data to collect, where the flow log data is to be published and whether it should be in text or pcap format.
Why is it important?:
VPC Flow Logs provides visibility into your network, enables you to resolve network issues more swiftly and ensures compliance with internal policies and regulatory standards.
Exam Tips:
1. Be aware that Flow Logs data doesn't include real-time information. There is a small latency between capturing the traffic and when it appears in CloudWatch or S3.
2. Know that Flow Logs do not capture all IP traffic. Certain types of traffic, such as traffic generated by instances communicating with Amazon DNS servers is not logged.
3. Understand the basic structure of a flow log record and what each field represents. This can come in useful for questions asking you to interpret a given log record.
4. Remember that enabling VPC Flow Logs incurs additional charges to your AWS bill and can impact performance, so there are scenarios where they may not be the best solution.
Go Premium
AWS Certified Solutions Architect - Associate Preparation Package (2024)
- 2203 Superior-grade AWS Certified Solutions Architect - Associate practice questions.
- Accelerated Mastery: Deep dive into critical topics to fast-track your mastery.
- Unlock Effortless AWS Certified Solutions Architect preparation: 5 full exams.
- 100% Satisfaction Guaranteed: Full refund with no questions if unsatisfied.
- Bonus: If you upgrade now you get upgraded access to all courses
- Risk-Free Decision: Start with a 7-day free trial - get premium features at no cost!