What is the primary function of a firewall in a network?

The primary function of a firewall in a network is to filter incoming and outgoing traffic. Firewalls serve as a security barrier between a trusted internal network and untrusted external sources, such as the internet. By analyzing the traffic that attempts to pass through it, a firewall can enforce predefined security rules that allow or deny access based on various criteria. This filtering function is essential for protecting the network from unauthorized access and potential attacks, ensuring that only legitimate and safe data packets are permitted to enter or leave the network.

The other options do not encompass the core purpose of a firewall. Providing Internet access is a function of routers and gateways, while managing IP addresses pertains to DHCP servers and network administration, and connecting different networks is a role typically fulfilled by routers. These functions are important in networking but do not capture the primary security role that firewalls play in traffic filtering and network protection.