Windows Server 2012 R2 may not be resolving IPv6 addresses from the local host file for a number of reasons. You might attempt the following troubleshooting steps:
Verify the IPv6 address: Make that the IPv6 address you entered in the host file is accurate and corresponds to the server's actual IPv6 address. The "ipconfig" command in the command prompt can be used to determine the server's IPv6 address.
Verify the host file: Make sure the host file is constructed correctly and that the IPv6 address entry is free of typos and syntax problems. An IPv6 address should be formatted as follows in the host file:
IPv6_address hostname
Restart the DNS Client service: Try restarting the server's DNS Client service. You can...