VPC flow logs
We briefly introduced VPC in Chapter 3. VPC is the core of the network configuration for every instance within AWS. Each AWS instance (Elastic Compute Cloud (EC2)) is assigned a VPC and uniquely identified using a VPC ID. VPC allows users complete control of the network environment, including defining specific IP addresses (non-public routable IPs), subnets, and security groups. Users can also configure a virtual private network (VPN) through their VPC connection. In default configurations, AWS will automatically create a VPC for every new instance of EC2. Users can also connect their EC2 instance to an existing preconfigured VPC instead.
All VPCs have a VPC identifier (VPC ID). The VPC ID is the single reference point for all network-related configuration items. For each instance, if you want to configure any network properties within AWS, you must look into each VPC specifically. In the next example, for a specific EC2 instance, certain details are captured for VPC...