Yes. The system has the ability to do that.
It is set to block IP ranges by default and will actively block them when it detects a large quantity of fraudulent attacks coming from that range.
The option can be turned on and off by going into the "Settings" tab and then into the "Manage auto-IP blocking" sub tab.
Additionally, you can manually add an IP range to your exclusion lists by adding it to your "add your own IPs" list which can also be found under the "Settings" tab and then in the "Manage auto-IP blocking" sub tab.
In order to exclude an IP range, replace the fourth (or in more severe cases the third) quadrant with an asterisk *.
For example: 1.2.3.* or 1.2.*.*