One of the fastest port scanner.
- Official Documentation (GitHub)
Installation
sudo apt install masscan
Usage

Masscan requires root access in order to access raw sockets.
sudo masscan -p80 x.x.x.x/24 --rate=1000 -e eth0
sudo masscan -p80 x.x.x.x/24 --rate=1000 -e eth0 --router-ip x.x.x.1