SOLVED members of an ISP (KPN) have issues viewing websites on my server

[Jan-Paul Kleijn]

It appears that a select group of people cannot view the websites on my server anymore. It happens only to users that have a certain ISP (KPN).

It is a very strange issue for me and also everybody that gets involved in it. TransIP helpdesk said it could be that I have blocked a whole IP range in my firewall, but ofcourse I didn't.

Can anyone give me some input on this?

EasyApache 3
PHP (DSO)
ModSec
ConfigServer Firewall

 

[cPanelMichael]

Hello,

You should be able to search for the IP address of an affected user in your CSF logs, or in the Apache error log (/usr/local/apache/logs/error_log) to verify if it's blocked by a firewall or Mod Security rule on your system.

If you don't see any results in those logs, then you may want to have one of the affected users try using traceroute from their computer to your website to see where the connection is rejected.

Thank you.

 

[Jan-Paul Kleijn]

Thanks cPanelMichael,
It appeared to be more of a deception that had me fooled fortunately. I flushed all IP addresses from my csf.deny list and the issue was resolved.