New
#11
What rang bells for me was when you said it was set to Public and also said "Unidentified Network". This indicates that your computer failed to get an IP Address from your router and had the default 127.0.0.1 hence why you couldn't "ping DATA", setting your own IP and Subnet etc fixes that which is why you could then "ping DATA".
Remember if you connect to a different network you'll probably have to change that static IP address, so I would start diagnosing why your DHCP wasn't working, perhaps the service wasn't running properly if UPNP Device Host was also not running?