After update to Extreme Control (NAC) 188.8.131.52 the engine stops responding to radius
The engine does not respond to radius requests. In the nacstatus output you can see for the Voss/Boss switches 2 mibs are used, GenericSwitchIpResolutionSnmpWorker (IpNetToPhysicalIpResolutionSnmpWorker, ExtrVossBossIpNetToMediaIpResolutionSnmpWorker)
Extreme Control 184.108.40.206
This is caused by a bug that is causing NAC to use a wrong mib to resolve IP addresses for the authenticated clients. Because of this the IP Resolve Address Queue fills up and throttles other authentication requests.
The bug is known as CR net0057331 and is fixed in 8.3.1.