Use the telnet client (add the windows component). Confirm a TCP connection to graph.oculus.com fails, then confirm you can hit a known good address.
From a command line: telnet graph.oculus.com 443 telnet www.google.com 443
Failure will tell you so. Success will give a blank screen.
If both fail then it's likely something local.
"Tracert graph.oculus.com" will give you all the hops between you and the server. A firewall giving you trouble is likely on one of the first few hops.