I have a WinXP host with VirtualBox 3.1.2 installed. I have a VirtualBox image called "hydrogen" on which I installed WinXP and MS SQL Server 2005 Express. I have another VirtualBox image called "helium" on which I installed WinXP. I am trying to create a ODBC DSN on "helium" that connects to SQL Server on "hydrogen" but it fails.
All of the documentation I've seen so far only says to use a "bridged adapter" in my VirtualBox image settings. I've done that but I still don't have communication.
The express edition does not listen on remote ports by default. You can enable remote connections using the "Surface Area Configuration Tool" or by running this SQL script:
exec sys.sp_configure N'remote access', N'1'
go
reconfigure with override
go
Also, if you use a bridged adapter, your virtual boxes are sharing your host's IP address. That means you'll have to configure both instances of SQL Server on a separate port.
I've gone through a couple of tweaks and changes and I have it working. My environment:
On "Hydrogen", I ran the Network Setup wizard, specifying that it was part of a network that did not have an internet connect (part of the "Other" option). I rebooted "Hydrogen".
On "Helium", I ran the Network Setup wizard, specifying taht it ws part of a network that did not have an internet connect (part of the "Other" option). I rebooted "Helium".
I turned off the firewall on "Hydrogen".
I can now connect to SQL Server on "Hydrogen" from both "Helium" and my host. Some of these settings may be extraneous; I don't know. But I know it's working for me reliably now, even after rebooting the host.