When they are logged in they can ping their own pc even with the DNS name.
When i let them log in trough the clientportal. They can make RDP to their own pc.
Please advise the following:
Can you ping 192.168.1.14? and can you try to telnet on port 3389 to 192.168.1.14 from a DOS prompt?
Also, if the RDP server 192.168.1.14 allowing connection from different IP subnet? Does it have a PC firewall that might be blocking the access? You might want to try to disable the Windows firewall on 192.168.1.14.