proftpd with error

# /etc/init.d/proftpd start
$Starting FTP services: - warning: unable to determine IP address of '_none_'
- error: no valid servers configured
- Fatal: error processing configuration file '/tmp/proftpd/proftpd.conf'


1. Use hostname to set your hostname
2. make sure your /etc/hosts, it should be
127.0.0.1 hostname groupname localhost
3. start your proftpd, it should be work well

proftpd will retrieve your hostname, and look up /etc/hosts to find your ip address.