What does an access control list (ACL) define?

• A. Allowed IP addresses and network protocols
• B. User permissions and resource access rules
• C. Security measures for data encryption
• D. Firewall configurations for incoming and outgoing traffic

Answer: (B)

An access control list (ACL) defines user permissions and resource access rules within a network environment. Its primary purpose is to determine who can access specific data or services and what actions they are permitted to perform, such as read, write, execute, or delete files. This makes ACLs a crucial component in enforcing security policies and ensuring that only authorized users can interact with various resources.

ACLs can be applied to various types of resources, including files, folders, or network devices. By specifying permissions for different users or groups, ACLs help to maintain control over sensitive data, thereby reducing the risk of unauthorized access and potential security breaches.

In contrast, while allowed IP addresses and network protocols (the first option) can be part of an ACL in a network context, the specific focus of ACLs is on user and resource permissions. Security measures for data encryption (the third option) and firewall configurations for traffic (the fourth option) relate to broader aspects of network security but do not directly define the role of ACLs.