What is the function of a firewall in a network?

The primary function of a firewall in a network is to filter incoming and outgoing network traffic. This is achieved by establishing a barrier between a trusted internal network and untrusted external networks, such as the internet. Firewalls use a set of predefined rules to allow or deny traffic based on various criteria, such as IP addresses, protocols, and port numbers. This filtering process helps to protect the network from unauthorized access, malware, and other security threats by monitoring and controlling the data packets that are sent and received.

For example, if an incoming packet is marked as suspicious or does not meet the established security policies, the firewall can block it, preventing potential attacks from reaching vulnerable systems within the network. Similarly, it can restrict certain types of outgoing traffic to prevent sensitive data from leaving the network unintentionally.

The other options do not accurately describe the role of a firewall. While firewalls do not focus on increasing internet speed or directly connecting multiple devices—functions typically related to routers or switches—they serve a crucial security role by regulating traffic based on security policies. Additionally, data storage security is a different aspect of network management that involves encryption, secure backups, and proper access controls, which are not functions provided by firewalls.