Is it necessary to separate Devices in ADOMS by FortiOS version?

Separating devices in ADOMS (ADomains) by FortiOS version is not a requirement. The primary function of ADOMs within FortiAnalyzer is to allow you to manage a group of devices, logs, and configurations without requiring them to be on the same version of FortiOS. FortiAnalyzer is designed to be flexible and compatible with various FortiOS versions, enabling you to aggregate and analyze logs from devices running different versions simultaneously without operational issues.

This flexibility allows network administrators to manage their devices more efficiently, especially in environments where devices may be updated at different times or where legacy systems are in place. While using specific features might benefit from particular FortiOS versions, the overall architecture and functionality of ADOMs support a heterogeneous environment, thus reinforcing why the FortiOS version does not matter in the context of ADOM configuration.