I hope you are doing good.
I have created the below setup on your controller tocheck the connection failure issue on lab APs. Thereafter, I have mapped thewrong vlan under the Wlan settings to fail the clients to get an IP from theDHCP. So, the APs should show the connection failure rate in the UI.
1) Zone: Ruckus Test 3.6.2 and Wlan: 00Test-3.6.2Client's devices were failed to connect to the SSID(00Test-3.6.2) due to theDHCP issue. I could see 100% connection failure rate and historical report ofclient's connection under the health Tab of the AP. The AP was displayed theaccurate results in the UI.
2) Zone: Ruckus Test 3.5.1 and Wlan: 00Test-3.5.1 I haveconnected the same devices to the SSID(00Test-3.5.1) to check the failure rateand noticed that there were no connection failures reported on the AP for theclients who were failed to connect to the SSID.
I have analyzed the flagged APs(Default Zone) in yourcontroller and could see the connection failures reported due to the DHCPfailure. Client might have faced the difficulty to get an IP from the DHCPserver at that moment. Please see the attached screenshot of historical reportfor your reference. The above test concludes that the connection failurealgorithm is not working properly in the 3.5.1 software version and there is nomiscalculation of connection failures in the 3.6.2.0.222 version.
As I informed earlier, the connection failure rate thatis shown in the UI is a cumulative value of the AP. The AP would take intoaccount Auth, Assoc, EAP, RADIUS and DHCP for reporting connection failures.
In 3.5, SZ maintains theconnection failure history for up to 1 week, AP reports failures in multiplecounters to the controller. In 3.6.2 it is changed to use a different counterthat was delta.
Please refer 3.6.2 ReleaseNotes:
ER-6198:Resolved an issue where the controller kept a track of old client connectiondata, which resulted in incorrect display of client connection failures.
https://support.ruckuswireless.com/documents/2435-smartzone-3-6-2-0-78-mr2-release-notes
To understand these failures,you can select an AP where you are seeing high failures and go to health tabfor that AP. Under the health tab you have two sections, one for performanceand the other for client connection failures. If you go to client connectionfailures you will have complete plots showing under which above category arethe failures happening. Now if necessary you can choose failure types as showbelow and also click on individual failure type to see which clients are failing.This feature was introduced to help customer debug his network issues."