How are trust levels defined in firewalld?

In firewalld, trust levels are defined through predefined zones. Each zone represents a specific level of trust for network connections and can have its own set of rules that determine what traffic is allowed or denied. Zones categorize network interfaces and connections based on their security levels and are designed to provide a flexible way to apply different firewall rules depending on the network environment.

For example, a public zone may have stricter rules as it is designed to be used on untrusted networks, while a trusted zone may allow more open access since it is meant for more secure environments. The use of these predefined zones allows system administrators to quickly and easily configure the firewall based on the security needs of various network segments without having to define every rule from scratch. This structure simplifies the management of firewall settings and enhances security by ensuring that appropriate levels of trust are assigned accordingly.