database timeouts when trying to connect to SQL server using Windows Authentication

Currently having issues with connecting to a SQL server database, wondering if anyone has any useful suggestions. Both the RStudio Connect server and the SQL server are on the same LAN, can ping the SQL server from our rsconnect server fine. The RStudio Connect server is Ubuntu 20.04, SQL server is part of a HADR cluster.

We have been able to authenticate using Sql authentication (e.g. with a username and password), but would prefer to use Windows authentication. Here in lies part of the issue as we aren't able (bureaucratic rather than technical) to join to the domain. We have been able to get Kerberos to work and generate tickets using kinit.

We stumbled on a few issues initially with an error that is now resolved ("Unspecified GSS failure/Server not found in Kerberos database"), that was specifying a server_spn different from the default in the connection string.

The issue that we are now getting is that he connection is timing out. I've verified the driver name is correct (I set up both SQLServer and SQL Server in the odbcinst.ini file, both names give the same issue)

con <- dbConnect(odbc(), .connection_string = "DRIVER={SQLServer};Server=****;trusted_connection=true;integrated_security=true;server_spn=****/****;")

any pointers would be greatly appreciated, thanks!

So sorry to hear about your troubles! ODBC connections can certainly be difficult at times. Are you using the SQL Server driver provided by RStudio? If so, filing a support ticket by reaching out to would be a great way to work to resolve this issue.
If you'd like to open a ticket, it would be helpful to enable driver logging and include the generated logfiles with the support request. This will allow us to easily escalate this issue to the driver vendor if needed.