https://www.drupal.org/files/images/ip_ranges.png would allow you to ban IP ranges.
Or if it is just form submissions, you could also try https://www.drupal.org/project/fbip to automate IP blocking by Drupal.
Tanay
On Sat, Jan 3, 2015 at 8:56 AM, mick bareman@tpg.com.au wrote:
I am copping upto 50 access violations per day, 90% of them from 1 of 4 subnets and instead of banning each IP address I would like to ban the entire subnets they are comming from, eg 66.249.65.74 is one of many similar addresses instead of individually banning 66.249.64.0 thru 66.249.95.255 I wish I could enter 66.249.64.0/19 and be done with that group of trouble makers.
I'm also curious about cron appearing to be run by these unauthorised users.