What is the difference between active mode and passive mode for Zabbix proxies?

The distinction between active mode and passive mode for Zabbix proxies centers on how communication occurs between the proxy and the Zabbix server. In active mode, the proxy establishes a connection to the server independently. This means it initiates the communication, allowing it to send collected data to the server and retrieve any necessary configurations. This approach is beneficial in scenarios where the proxy needs to report back to the server about the collected metrics on a regular basis.

In passive mode, however, the communication dynamics change. The server is responsible for connecting to the proxy and requesting data. This mode relies on the server reaching out to the proxy for updates and data retrieval, which can be useful in environments where direct outbound connections from the proxy might be restricted or complex.

This understanding of how the two modes operate clarifies why the answer is focused on the connection behavior, highlighting the active mode's role in initiating connections and the passive mode's reliance on server-initiated connections. This mechanism significantly affects how data is transmitted and managed in a Zabbix installation, influencing performance, security, and configuration scenarios.