What is the function of a firewall in a network?

The function of a firewall in a network is to monitor and control incoming and outgoing network traffic based on predetermined security rules. Firewalls serve as a security barrier that establishes a controlled environment between trusted internal networks and untrusted external networks, such as the internet. By implementing specific rules regarding what traffic can pass through the firewall, it effectively helps to prevent unauthorized access and potential threats from reaching sensitive data or systems within the network.

Firewalls can filter traffic based on various criteria such as IP addresses, protocols, and port numbers, allowing organizations to maintain security policies tailored to their needs. This ability to evaluate and manage traffic contributes to the overall security posture of the network, helping to protect it from various cyber threats, including unauthorized access, malware, and denial-of-service attacks.

In contrast, the other options do not accurately describe the primary role of a firewall:

• Encrypting email communications is the function of encryption protocols, not firewalls.
• Acting as a physical barrier refers to physical security measures, such as locks and access controls, rather than the data packet filtering and monitoring done by firewalls.
• Providing wireless connectivity for mobile devices pertains to wireless access points and not to the firewall's function.