FTP - Port 21

Common usage

ftp [email protected]

Anonymous login

ftp [email protected]

ftp <IP>
>anonymous
>anonymous
>ls -a # List all files (even hidden) (yes, they could be hidden)
>binary #Set transmission to binary instead of ascii
>ascii #Set transmission to ascii instead of binary
>bye #exit

Source : https://book.hacktricks.xyz/network-services-pentesting/pentesting-ftp