I'm trying to register a database connection within ArcGIS Server that is on a different domain than my client (with no trusted bridge). I can make an admin ArcGIS Server connection from ArcGIS Desktop on my client. When I then try to register a database connection, I enter the connection information to my "Publisher Database" (on same domain as my client), and that succeeds, however when I try to enter the "Server Database" connection information it fails. ArcGIS Desktop on my client is trying to validate the connection to a server that it can't see. Knowing this would be a likely issue, why can't we manually type the connection information in. That way we can create the .SDE file that's needed to import the connection within ArcGIS Server Manager. Within the AGS Manager web page, there is only an option to import a connection to the database your trying to register. If your server environment does not have ArcGIS Desktop, you cannot create a valid file to import.
My goal is to build a map service within a development environment that's reading data from a SQL Server database on one domain, then migrate that service to a production environment on a different (air gapped) domain. Maybe I'm doing something wrong. Can anyone shed some light on this, and help me out?