I have SQL Server 2008 R2 Datacenter running on Windows Server 2008.
I am unable to connect to a named instance \SQL2008R2 using its instace name over the internet from my development machine (e.g. mydbserver.com\SQL2008R2 from SSMS).
The instance is configured to listen on port 49180. If I try to connect using the specific port number everything works okay (e.g. mydbserver.com,49180 from SSMS).
The SQL Server Browser service is running, and I have opened UDP port 1434 on the server firewall (inbound and outbound).
I have no problems connecting a range of SQL Server instances from my machine. I have also tried connecting from a couple of other machines with no luck.
It seems to me that SQL Server Browser might not not be serving up the port number to my machine - is there any way to confirm/fix this? Or could it be something else?
Sounds like something is wrong with the browser. Try restarting the SQL Browser service.
Does sound rather strange. I have used portqry to resolve issues in the past. Might be worth giving it a try
This blog post explains how to use it