ftp localhost 8021
Connected to localhost.
220 (vsFTPd 3.0.3)
Name (localhost:asac): anonymous
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> passive
Passive mode on.
ftp> ls
227 Entering Passive Mode (10,0,2,2,230,77)
ftp: connect: No route to host
ftp> ls
.
Passive mode refused.
ftp> !ls
empty	  parts  run-vsftpd		     snap	     stage	      vsftpd
icon.png  pkg	 scan-and-go_1.0_amd64.snap  snapcraft.yaml  vsftp-base.conf
ftp> active mode
?Invalid command
ftp> active
?Invalid command
ftp> passive off
Passive mode off.
ftp> active
?Invalid command
ftp> ls
227 Entering Passive Mode (10,0,2,2,191,221)
.
ftp> ls
500 Illegal PORT command.
ftp: bind: Address already in use
ftp> ls
425 Use PORT or PASV first.
ftp> ls
500 Illegal PORT command.
ftp> port
?Invalid command
ftp> help port
?Invalid help command port
ftp> pasv
?Invalid command
ftp> passive on
Passive mode on.
ftp> 
ftp> 
ftp> ls
500 Illegal PORT command.
Passive mode refused.
ftp> ls
500 Illegal PORT command.
Passive mode refused.
ftp> l;s
?Invalid command
ftp> ls
227 Entering Passive Mode (10,0,2,2,231,201)
ftp: connect: No route to host
ftp> .