wtf is masscan?

Masscan is a tool that finds open ports on computers across a network, really fast. It can scan the entire internet in under six minutes, sending out 10 million probe packets per second. If you've ever used nmap to check which ports are open on a server, this does the same thing, just orders of magnitude quicker. The reason it's so fast comes down to how it sends and receives probes. Traditional scanners send a probe, wait for a response, then send the next one. Masscan instead fires off probes continuously without waiting for replies, using separate threads for sending and receiving. It also randomizes the order of addresses it scans so no single network gets overwhelmed by the traffic. At the engineering level, it uses encryption to shuffle a simple counter into random IP-and-port combinations, and it can bypass the operating system's networking stack entirely when paired with specialized drivers and hardware. The people who'd use this are security researchers, network administrators, or anyone who needs to map large networks quickly. For example, if you wanted to find every device on a corporate network with port 80 open (the standard web port), you could point it at a range like 10.0.0.0/8 and get results in seconds. At the extreme end, researchers use it to scan the whole internet for exposed services, though the README warns that scanning the internet carelessly can get you banned by networks that don't appreciate being probed. One notable tradeoff: masscan prioritizes raw speed over the deeper features of a tool like nmap. It won't resolve DNS names, detect operating systems, or do service fingerprinting the way nmap can. It also requires care with transmit rates, by default it's throttled to 100 packets per second, and the README emphasizes that cranking it up can overwhelm your own network hardware. It offers config files, output in XML or binary format, and the ability to split scans across multiple machines for even more speed.