When you try to log in to the WordPress installation, you may occasionally get this error message.
Your IP has been flagged for potential security violations. Find out more...
What the message states is that the IP has been blocked and the user will not be entitled to log into his own wordpress installation.
Jetpack brute force feature
This is part of a new feature introduced by Jetpack, the wordpress plugin, to prevent brute force attacks in which the hacker attempts to guess the username and password by making repeated login attempts.
How to unblock the IP address?
There are three ways in which the IP can be unblocked. In all the three methods, the IP address of the user has to be whitelisted.
In the first method, if you have access to your site and you’ve not been blocked, you can enter your IP or IPv6 address(es) by going to Jetpack → Settings → Security → Protect.
In the second method, if you are blocked from entering your site, you can enter the IP or IPv6 address(es) via WordPress.com by visiting My Sites → Settings → Security → Whitelist.
In the third method, you can also whitelist one IP address by setting it as the JETPACK_IP_ADDRESS_OK constant in your wp-config.php like this:
How to find the IP Address?
The error message shown by the Jetpack plugin itself shows the IP address. However, if you want to double check it, you can find your IP address by visiting any of the following sites:
How long is an IP blocked? There is not set amount of time. The length of time is based on a number of factors which have not been specified.