How many subnets can a single Access Control List (ACL) be associated with?

An Access Control List (ACL) in Amazon Web Services (AWS) can be associated with multiple subnets within a Virtual Private Cloud (VPC). This feature allows for the implementation of network security rules across various subnets, providing flexibility in defining inbound and outbound traffic permissions. By associating the same ACL with multiple subnets, an organization can maintain consistent security policies across different segments of their network while optimizing management efforts.

In contrast, if an ACL were limited to a single subnet, it would reduce the ability to apply uniform security controls across a network, potentially leading to inconsistencies in traffic management and increased complexity. Additionally, the ability to associate an ACL with multiple subnets enhances the scalability of security practices as the network grows or changes over time.