MS SQL Servers

From a host with a network route to SQL Server's TDS endpoint (including an Internet route only when the service is exposed there), use an authenticated Windows session to enable and invoke the built-in xp_cmdshell for operating-system command execution, then separately inspect registered server definitions. xp_cmdshell runs synchronously under the SQL Server service or configured proxy account according to SQL permissions. The catalog query reads server metadata and does not prove that a remote link is usable. Internet exposure is a deployment condition, not implied for all SQL Servers.