Subnet Mask of 255.0.0.0

I’m at a Responsive Web Trends Conference in San Francisco hosted by Moboom. The network setup is a bit unorthodox. The subnet mask is set to 255.0.0.0. Based on my experience, this network is /8, which allows up to 16,777,214 hosts. It uses the entire range of reserved private IP addresses starting from 10.0.0.0 to 10.255.255.255. Interesting setup. I just ran a speed test. Download is 50 Mbps and upload is 27 Mbps.