Do you have an ftp daemon installed and running?
Debian has packages: ftpd, inetutils-ftpd, krb5-ftpd, muddleftpd, oftpd, proftpd, pure-ftpd, pyftpd, and a few others. Each package may log errors to it's own log file, but they are probably all in /var/log/ or a subdirectory.
This command will show you if any process is listening to the ftp port. Run it as root to see the PID and process name:
Code:
netstat -lp --ip | grep ftp
This command will show you if an ftp daemon is running (run as root):