This is a fairly specific issue, but I’m at a loss for reasons to what might be happening.
We have SQL Server 2008 running on what we’ll call ServerA. We can RDP in ServerA, we can ping ServerA. If we RDP into ServerA, we can open up SQL Server Management Studio and connect to all of the database instances running on ServerA just fine.
However,
We can’t connect to any of those instances from anywhere else on the network. I don’t think its a network problem, because if I can RDP and ping ServerA, then the network is fine. And I don’t think its a permission thing, because if I’m RDP’d in, I can connect to all the instances just fine. It’s almost like I’ve got some secret safety setting turned on that’s preventing connections from any IP other than localhost, or something like that.
Does such a safety setting exist? I wouldn’t know how to get into this state even I wanted to, so I have no idea how to get out of it.
SQL Server allows connection via four different protocols:
Of these, only Shared Memory is enabled if you’ve installed SQL Server with default settings.
See the protocols:
Shared Memory only works locally on the database server. This is likely the protocol being used when you RDP to the server and open SQL Server Management Studio (SSMS).
TCP/IP is normally used when connecting from a remote machine to the database server. TCP/IP uses ports, and the default port for SQL Server is 1433. If you have a firewall installed on your database server, you may need to open this port.
Enabling the TCP/IP protocol:
Restarting the SQL Server service:
You should now be able to connect SSMS from remote machines to SQL Server running on your database server.