Hi,
We have Windows 2008 R2 RDS farm internally and publishing RDS Sessions with Windows 2012 RD Gateway. All servers are using valid SSL certificates (public CA signed). XP RDP Client will fail to connect at the first attampted and get the following error:
"Your Computer can't connect to remote computer because the Remote Desktop Gateway server is temporarily unavailable. Try reconnecting later or contact your network administrator for assistance."
When it failed to connect, if the client "Connect" again without exit out the RDP Client, it will connect successfully.
In addition, the Windows 2012 RD Gateway is dedicated server for publishing the RDS. Therefore, it doesn't not have any 3rd party application and it was a new install.
Thanks very much
Aldous