PING has been disable in hyper-v Core 2012 by default so you can enable,

SELECT the option : 4 in Server Configuration, you will get server response PING so you can ENABLE.

OR type the following command in cmd prompt,

netsh firewall set icmpsetting 8

Link here to get more idea: How to use the “netsh advfirewall firewall” context instead of the “netsh firewall”