Hi,
I believe you can do it by two rules:
rule 1 (higher position = higher priority) will have conditions:
authentication is 802.1x
endsystem group is domain computer
apply profile "authorized domain computer"
Rule 2 (lower position = lower priority than rule 1) will have condition:
authentication is 802.1X
apply profile "restricted access to basic services"
first time the computer connects will go through rule 2. then computer will update DNS records and hostname resolution will reauthenticate the endsystem. reauthentication will hit the rule 1.
"endsystem group is domain computer" does verify hostname in LDAP
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another option how to solve your issue (from my point of view more secure): use EAP-TLS = provision your domain computers with certificates. if the EAP-TLS is used then you know the device is under domain control.
Another option is to use PEAP and verify the username is "host/*" then you know it is computer in the domain
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good luck
Z.
Regards
Zdeněk Pala