What is the difference between 'FQDN' & 'Hostname' parameter available in the ClearPass Server configuration?
The FQDN parameter is primarily used for SSO functionality with any external IDP servers. We can configure the VIP hostname of a ClearPass cluster to be the FQDN.
'Hostname' parameter in the Administration --> Server Configuration, does not need to be an FQDN. We can specify any user defined names. If we need to join the ClearPass cluster members to the same Active directory domain, then hostname should be different. Otherwise, it will create duplicate computer/machine accounts for ClearPass Server in the Domain Controller and may lead to PEAP-EAP-MSCHAPv2 authentication issues/failures for the clients against Active Directory.