writing this post because see a lot of message related to the compatibility regarding 5.2.x and 5.0.x which means. As an example: The new FAP's like 24D and/or 21D are coming with a Branche Release loaded based on 5.2.x (Branch 4117/4118). This means the question is what to be used that this FAP's are working fine? Following:
- If you use 5.2.x on FortiGate you are compatible to FAP's based on 5.2.x but it is recommended to use latest version for FortiGate meaning at the moment 5.2.2. On FAP's as soon as the official released are launched you should upgrade asap to this version. For the FAP 24D/21D the official Firmware are not yet available. Remember in such a constellation you can use full feature set based on 5.2.x.
- If you use 5.0.x on FortiGate and YOU DO NOT USE FAP's based on 802.11ac it is recommended to use FAP's based on 5.2 latest release. To what the FAP's based on 5.2 are compabible regarding FortiGate Release based on 5.0.x you can have a look to the Release Notes. In this scenario it is also recommended to use on FortiGate 5.0.x as on FAP's 5.2.x latest release. Of course in such a scenarion you can only used Wireless Feature based on FortiGate 5.0.x and not the new features based on FortiGate 5.2 even you have on the FAP's 5.2. The reason is that the Wirless Controller is responsible for the available features and not the FAP's.
- If you use FAP's based on new Wirless Standard 802.11ac like FAP-221C/321C and you would like to go with on the FortiGate based on the release 5.0.x YOU HAVE TO USE the "Special Build Support" Release available under:
FortiGate > Download > 5.0 > Feature Support > Version you would like to get (latest 5.0.11)
From this point of view here a short overview of the possibilites:
FortiGate 5.2.x --> You must use FAP's based on 5.2.x (all model's incl. FAP-221C/321C)
FortiGate 5.0.x --> You can use Forti Access Point 5.0.x but recommended Forti Access Point 5.2.x
FortiGate 5.0.x (Special Support Build) --> You can use Forti Access Point 5.0.x but recommended Forti Access Point 5.2.x
Kee in mind it is absolutly recommended to use on the FAP's based on 5.2 always the latest releases specially in case of problems but look that this release you use on the FAP is backward compatible to the 5.0.x release on the FortiGate and/or 5.2 release on the FortiGate. To evaluet this please have a look to the release notes of the FAP/FGT.
hope this helps