I have installed csf on my Xen virtual server that I manage with WHM/cPanel & am now trying to configure it to tighten up security. I tried enabling SMTP_BLOCK but when I do this CSF fails with the rather unhelpful error messages below. Any ideas how to fix this?
DROP tcp opt -- in * out * 0.0.0.0/0 -> 0.0.0.0/0 tcp dpt:25
iptables: Unknown error 4294967295
ACCEPT tcp opt -- in * out * 0.0.0.0/0 -> 0.0.0.0/0 tcp dpt:25 OWNER UID match 0
Error: Error processing command for line [589] (10 times): [iptables: Unknown error 4294967295], at line 589
...Done.
Restarting lfd...
Stopping lfd:[ OK ]
[ OK ]
Starting lfd:
Error: You have an unresolved error when starting csf. You need to restart csf successfully before starting lfd (see /etc/csf/csf.error)
[ OK ]
Had the same problem on one server. Disabled the SMTP_BLOCK, started csf, and then enabled SMTP_BLOCK again and restarted csf and it worked. No idea why...