When in proxy mode, you must set a range of allowable ports that the Microsoft RDP client can use. CommandCenter Secure Gateway allows up to 100 simultaneous proxied Microsoft RDP connections. The allowable range may be greater than 100.
Your client computer must be using IPv4 to communicate with CommandCenter Secure Gateway. If the client computer and CommandCenter Secure Gateway are dual-stack, the DNS must resolve to an IPv4 address.
RDP target addresses must be IPv4. If the RDP target is specified by hostname, the hostname must be able to resolve to an IPv4 address.