VPC Flow Log Overview

What Is a VPC Flow Log?

A VPC flow log records information about the traffic going to and from a VPC. VPC flow logs help you monitor network traffic, analyze network attacks, and determine whether security group and network ACL rules require modification.

VPC flow logs must be used together with the Log Tank Service (LTS). Before you create a VPC flow log, you need to create a log group and a log topic in LTS. Figure 1 shows the process for configuring VPC flow logs.

Figure 1 Configuring VPC flow logs

Notes and Constraints

• The following lists ECS types that support VPC flow logs in each region.
  • eu-west-1: C3, CC3, S3, and I3
  • eu-west-0: C3, CC3, S3, I3, P2, H1, and M2
• Each account can have up to 10 VPC flow logs in a region.