AWS Networking: Understanding VPC Security Layers
As organizations prioritize cloud security, Amazon Web Services (AWS) offers robust features to ensure data protection. The Virtual Private Cloud (VPC) provides a secure and isolated environment for resources. Two essential security layers are Network Access Control Lists (ACLs) and Security Groups.
Network ACLs function as virtual firewalls at the subnet level, allowing granular control over inbound and outbound traffic. By default, ACLs allow all traffic in and out of the subnet, but can be customized to restrict data flow based on specific protocols and ports. This ensures secure communication between EC2 instances within a VPC.
Security Groups, on the other hand, operate at the instance level, providing stateful firewall-like functionality. By default, Security Groups block all inbound traffic and allow all outbound traffic. Inbound rules must be created to allow incoming connections from the internet or other networks.
Organizations can also use Security Groups to isolate resources into different tiers, controlling network communication between them. This is a key advantage of AWS VPCs over traditional on-premises environments, where VLAN configurations are often used for isolation.