Well, then I noticed that in the days after that server installation, I frequently found my website "reject ALL visitors" with following message:
You are a spammer, hacker or an otherwise bad person.
I know this sentence is from Admin Tools, since my website is running Admin Tools Professional 4.0.2 version.
Then I have rename the file "main.php" of Admin Tools via FTP to login in backend.
In the "Admin Tools -> Web Application Firewall -> Auto IP Blocking Administration" I noticed that the IP address of my own server was there!
Look, this is not an IP address of any visitor terminal, but my server itself!
My VPS is using "dedicated IP" , so that IP address does NOT belong to any PC or mobile device of any visitor.
Then I checked the "Security Exceptions Log" and searched my server IP address there, I got following reasons for that single IP:
Admin Query String Login failure UploadShield CSRF Shield
Maybe there were more (more than 10 pages), I did not read them all, just list several here.
I just wonder: Why the IP address of my website server could be blocked?
Does this means that some hacker had broken into my server and use it as a source of attacking terminal?
Is there any option to add my server IP as the "Permanent Whitelist"?
Thank you.