What does a firewall typically utilize to control traffic?

A firewall typically utilizes Access Control Lists (ACLs) to manage and control incoming and outgoing traffic across a network. ACLs are a set of rules that define which traffic is allowed or denied based on criteria such as IP addresses, port numbers, and protocols. By using these lists, firewalls can effectively filter traffic, ensuring that only authorized users and devices can access certain network resources, while blocking potentially harmful traffic from unauthorized sources.

Access Control Lists serve as a crucial security mechanism that helps maintain the integrity of network communications, as they can be finely tuned to allow or deny specific types of traffic based on defined policies. This method is essential for preventing unauthorized access and mitigating security threats, making it a foundational component of firewall operations.

The other options, while relevant to network security, do not directly address the primary function of controlling traffic in the way that ACLs do. Network Address Translation (NAT) is more about modifying IP address information for efficient address management and may not filter traffic based on rules. Header Inspection Techniques relate to examining packet headers but do not encompass the broad rule-based access management provided by ACLs. Protocol Encryption focuses on securing data during transmission rather than controlling which traffic is allowed into or out of a network.