Thanks a lot, i got it.
LDAP browsing works fine, but i noticed, that there was no computer objekt of the clearpass machine in AD.
So I leave Domain an rejoin Domain.
Afterwards it worked.
But now there is another problem.
I built up a service wich should match on this PEAP connections like following:
Radius:IETF NAS-Port-Type EQUALS Wireless-802.11 (19)
AND
Authentication InnerMethod Equals EAP-MSCHAPv2
In AccessTracker I can see in the computed attributes
Authentication:InnerMethod EAP-MSCHAPv2
But the Service does not match.
In my setup I need to handle peap supporting clients with a seperated service.
Any idea? Where is my mistake?