You most likely either have a configuration error in your csf.conf,
you've been blocked by lfd, a legacy script flushing iptables or a
problem with your VPS configuration by your VPS host:
1. Check you haven't been blocked by lfd by checking
/var/log/lfd.log (you or your VPS host provider may have to do this from
the VPS console)
2. Ensure that you use the default csf installation. There is no need to set the ETH_DEVICE setting
3. Check all of your root cron jobs and ensure that none of them are doing anything with iptables (especially flushing them) in:
/etc/crontab
/etc/cron.d/
/etc/cron.hourly/
/etc/cron.daily/
/var/spool/cron/root
4. If there are still problems, then it's most likely that your
VPS is not correctly configured by your VPS host provider. You need to
follow the following post and have your VPS host provider investigate:
http://forum.configserver.com/viewtopic.php?f=6&t=...
