Some changes in how libpcap works you should know

I thought I'd document the solution to this problem I had.

The API libpcap is the standard cross-platform way of sniffing packets off the network. It works on Windows (winpcap), macOS, and all the Unixes. It's better than simply opening a "raw socket" on Unix platforms because it takes advantage of higher performance capabilities of the system, including specialized sniffing hardware.