ftp명령어

The IP address 192.120.43.250 is the eth0 for my server. When I run the command

sudo vsftpd /etc/vsftpd.conf

I get the error:

500 OOPS: could not bind listening IPv4 socket

To check to see what was running on port 21, I ran the command:

sudo netsat -tulpn

And saw that vsftpd process id was 29383 so I issued the command:

sudo killserver 29383

And checked again. The vsftpd was still there, but with a different PID. Running the command:

sudo killall vsftpd

and

sudo killall -9 vsftpd

Does the same thing. I have already tried reinstalling. Anyone know what is going on and how to fix it?