For almost 2 years, I've had a Hyper-V virtual machine on my local Windows 10 (formerly 8.1) machine running IIS and connecting to my production SQL Server (the Hyper-V VM is a development machine). I decided to move the server to Hyper-V on a local (same network) Windows Server 2012 machine. Here's what I did:
I copied the virtual hard drives to the server and recreated the machine on that server - this is a new server and this is the first virtual machine on it. I booted up the virtual machine and set up IIS with my development site. It cannot connect to the SQL server, which is on Amazon AWS. If I copy the files to the base IIS installation on the host server (not the virtual it was hosting), it connects to SQL just fine.
I tried disabling the firewall completely on both the virtual and host server. No luck. I DO have an internet connection on the virtual machine. I also checked with AWS to make sure that it wasn't blocking the virtual server's IP and it isn't - my local network here only has one IP address and both are seen the same way (I checked).
So my theory is that there is some sort of network difference between how the virtual switch is set up in Windows 10 (which works) and Windows Server 2012 R2 (which doesn't). I tried messing with the Virtual Network Adapter ACL to allow anything from anywhere, but if that's what I need to do, I must have done it wrong.
I'm just really flummoxed by this one. It seems like this should be simple, but it isn't.