This problem just started recently. I have a number of VMs (2008 R2) on a 2012 Hyper-V host but not all are effected in the same manner. The VMs are identical and no changes were made to either the VM or Hyper-V host.
I am unable to reach the Cluster Shared Volume on a few VMs. I am able to ping the Hyper-V host by name and IP. But I cannot connect to the share via name, IP, or FQDN. I can reach other network shares okay, but not shares on the Hyper-V host.
Things that I have checked/tried - DNS does not seem to be an issue. I can ping by name and nslookup resolves correctly - 6to4 Adapter has been disabled - Windows firewall turned off for troubleshooting purposes - NETBIOS over TCP.IP is enabled - workstation/server/computer browser service is running. (Computer browser service is not running on the VMs that work) - Accessing the CSV from other servers (outside of the Hyper-V host) works just fine - Reboot Hyper-V Host and Reboot VM - File and print sharing service is enabled on both VM and Hyper-V host
Error: File and print sharing resource is online but isn't responding to connection attempts. The remote computer isn't responding to connections on port 445, possibly due to firewall or security policy settings, or because it might be temporarily unavailable. Windows couldn't find any problems with the firewall on your computer.
I might be missing something simple, but does anyone have a suggestion on something to try/check?
UPDATE: There was an unannounced change to the Enterprise Firewall. Which explains why I never saw anything in the Windows Firewall log. Not being able to connect over port 445 was the tell tale sign. I changed the IP of a working VM to a non working VM IP and noticed that I could no longer connect.