Pingdom inaccurate results needs whitelisting - firewall rule update error


Well-Known Member
Mar 30, 2012
cPanel Access Level
Website Owner
we use pingdom's free version to monitor whether our site is up/down.
It sometimes gives a series of 'server down' email alerts when the website can actually be reached quite normally.
It would be easy to write it off as a buggy service that gives wrong or inaccurate results, except for the fact that a lot of pingdom users seem to be very happy and sure that pingdom alerts are fairly accurate.

It seems that it is mostly a firewall issue - where if you have blocked an IP range due to some malicious activity from that region, and pingdom happens to have a server in that IP range, it reports a down alert as the ping is blocked.

These are the relevant links I found:
Simple tool to list Pingdom Probe IPs
Automatically update iptables rules for Pingdom monitors. | Personal blog of Chris Ergatides
Automatically update Pingdom firewall rules | MG IT Solutions

However when I tried out the last one - a script named, it gave a series of errors:
iptables: Bad rule (does a matching rule exist in that chain?)
iptables: No chain/target/match by that name
We are using csf+lfd as well and every blacklist entry in cphulkd is also entered into csf+lfd blacklist manually.

The alternative, as far as I understand would be to manually whitelist the IPs from the pingdom IP feed here:

Any pointers on how to fix this?

Any help is greatly appreciated.
Thanks in advance,


Quality Assurance Analyst
Staff member
Oct 2, 2010
somewhere over the rainbow
cPanel Access Level
Root Administrator
Re: Pingdom inaccurate results needs whitelisting - firewall rule update er

There's an option for CSF to enable dynamic IPs based on a hostname. You might consider using that instead. It's DYNDNS in the CSF configuration file.