What is the primary function of a host-based firewall?

The primary function of a host-based firewall is to allow or block data packets based on a set of security rules. This type of firewall is installed on individual devices, such as computers or servers, and it manages incoming and outgoing traffic solely for that particular host. The firewall protects the host by analyzing the data packets that attempt to enter or leave the system according to pre-defined rules, which can be customized by the user or system administrator.

The key to the operation of a host-based firewall is its ability to enforce these security rules, which can dictate which types of traffic are permissible based on criteria such as IP addresses, protocols, and port numbers. This granularity allows for tailored security approaches to different applications or services running on the device, enhancing protection against unauthorized access and potentially harmful traffic.

In contrast, other options describe functions that are outside the core responsibilities of a host-based firewall. Filtering traffic on a network switch pertains more to network firewalls or switches equipped with security features, while monitoring network traffic for malicious activities relates to intrusion detection systems rather than directly blocking traffic. Additionally, encrypting communications between devices involves a different technology, such as VPNs or secure communication protocols, rather than the primary function of a firewall.