Adding sharespace to domain gives me error msg [NET_ERROR: Join ADS failed]

hello i have 2 subnets :

(1) and (2)

windows server 2008 r2 is running on subnet (2)

when i want to add an client located in (1) to domain (2) then it works but it doesnt work with my nas device who is also located in (1)

my field inputs:

domain name:  domain name

domain controller ip-adress: the ip adress of the dc ( for example)

administrator: Administrator (i also tried Administrator@domain)

administrator pass: the Administrator’s pass (this is the pass you must type in by logging onto windows server 2008 r2 locally)

the Administrator account is of course existent in “active directory users and computers” in the “users” folder

i keep getting : 

NET_ERROR: Join ADS failed

what is wrong? any ideas ?


now nas device is in the same subnet like the windows server 2008 r2 but no success at all!