What is the main function of an access control list (ACL)?

The main function of an access control list (ACL) is to define user permissions for specific resources. ACLs are used in various contexts, such as operating systems, database management systems, and network devices, to grant or deny access to resources based on pre-defined rules. In networking, for instance, ACLs determine which packets are allowed or denied on a network interface based on factors like IP addresses, protocols, or ports.

By specifying permissions, ACLs help ensure that only authorized users can access certain assets, thereby enhancing security and managing the integrity of the system. This functionality is crucial in environments where sensitive information needs to be protected from unauthorized access.

While filtering outgoing network traffic, logging network activity, and controlling VPN connections are important aspects of network security, they represent specific applications or features that may utilize ACLs rather than the primary purpose of what an ACL itself is designed to do.