Have you ever faced with the lack of possibility of using NMap? For instance if you have reverse shell as an unprivileged user and there are no useful tools preinstalled?
This is a small script which will help you to scan a network if you have nothing.
chmod +x port-enum.sh
./port-enum.sh 192.168.1.1
or
bash port-enum.sh 192.168.1.1
https://www.ivanglinkin.com/simple-port-enumeration/
