Block certain IP addresses How to block certain IP addresses if we receive too many GET requests from particular IP addresses for a Drupal 7 website?
Drupal 7 has IP address blocking feature by default. 


Login to admin 
Navigate to configuration page
Click on "IP address blocking" which available in under People panel
Add IP address which you wanted to block. 


OR

Navigate to below page 
http://[yourwebsitename.com]/admin/config/people/ip-blocking