Which firewall functions allows legitimate traffic entry into a network?

The firewall function that allows legitimate traffic entry into a network is called "packet filtering." This process involves examining incoming packets and allowing or blocking them based on predefined security rules, such as source/destination IP addresses, port numbers, and protocols. Additionally, stateful inspection enhances this function by tracking active connections and making decisions based on the state of the traffic. Together, these mechanisms help ensure that only authorized traffic is permitted while unwanted or harmful traffic is blocked.