What must match between the Zabbix proxy and server versions for them to be compatible?

For the Zabbix proxy and server to be compatible, the major version must match. The major version indicates significant changes in the software that may introduce or modify core functionalities, which can impact communication and data handling between the proxy and the server. If there is a difference in the major version, it can lead to compatibility issues, causing the components to not function correctly or at all.

Matching only the minor version would not guarantee compatibility, as the minor version can include features or changes that may not be compatible with other major versions. The build number and release date are also not definitive indicators of compatibility. The build number might differ even within the same major version due to ongoing patches or minor updates, while the release date does not necessarily reflect version compatibility. Hence, ensuring that both the Zabbix proxy and server have the same major version is crucial for optimal operation and integration.