Try to stop/start xinetd:
``Also take a look at the /var/log/messages file for detailed error reports. The server hostname may not be resolved. In this case you should put the record like "SERVER_IP SERVER_HOSTNAME" into /etc/hosts.
Check firewall settings to be sure that 20/21 ports are opened with the following command:
[root@server ~]# iptables -nL | egrep "20|21"