I installed CSF and LFD on a "hardware node" server on which VPSes are running through the OpenVZ virtualization. I had a problem with the initial CSF setup because it was blocking traffic comming through the virtual "venet0" device.
So I created a csfpre.sh file with a few iptables rules that forward the venet0 traffic. It's working great but after the (automatic) CSF upgrade, I could not access any VPS on the server!
The upgrade logs revealed the reason:
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Running /etc/csf/csfpre.sh/etc/csf/csfpre.sh: line 1: iptables: command not found
/etc/csf/csfpre.sh: line 2: iptables: command not found
/etc/csf/csfpre.sh: line 3: iptables: command not found
/etc/csf/csfpre.sh: line 4: iptables: command not found
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So CSF was restarted without those special iptables rules needed for the VPS traffic to be properly forwarded.
I don't know what the exact reason was. Perhaps CSF could not find iptables in the standard path? But after restarting CSF by hand, everything is back to normal and works as before.
Strange...
Tomas