What is the function of a firewall in a network?

The primary function of a firewall in a network is to control incoming and outgoing network traffic. This is achieved by establishing a set of predefined security rules that determine which types of traffic are allowed to pass through and which are blocked. Firewalls serve as a barrier between a trusted internal network and untrusted external networks, such as the internet.

By analyzing packet data, firewalls can filter traffic based on various criteria, such as IP addresses, port numbers, and protocols. This helps in preventing unauthorized access to sensitive data and protects the network from potential threats. Firewalls can be implemented as hardware devices, software applications, or a combination of both.

The other options relate to important aspects of network management and security but do not specifically address the primary role of a firewall. Monitoring application performance involves assessing how well applications are functioning, while scanning for malware is a separate security measure designed to detect and mitigate malicious software. Improving internet speed pertains to optimization strategies rather than security or traffic control.