If you are configuring WPAD for your proxy server and you can seem to ping your WPAD CNAME record it’s because it disabled.
Starting with Windows Server 2008 WPAD is disabled by a new feature Microsoft set on the DNS serer called global query block list.
To enable the feature and be able to ping WPAD and use WPAD for auto proxy detection start the command line utillty and run:
dnscmd /config /enableglobalqueryblocklist 0
You can read more about Global Query bloc list in the link below: