For website owners that use the CloudFlare service, there are times where your sites may encounter a sharp increase in traffic that can render a site unable to respond with the content.
These attacks are called a DoS (Denial of Service) attack. The goal behind these kinds of attacks is precisely explained in the name, which is to stop your site from operating. This occurs because the server that hosts the site becomes overwhelmed trying to process the incoming traffic.
A variant of a DoS attack, known as a “DDoS” (Distributed Denial of Service) attack, functions very similarly in concept with a significantly harrowing difference. This traffic is distributed from multiple locations. This makes addressing an attack of that caliber rather difficult to manage.
Due to the way that CloudFlare handles traffic you can rather efficiently handle overwhelming requests by enabling a filter mode called “I’m Under Attack.”
You can enable this by accessing your CloudFlare account
Select the desired website product.
Select the Firewall app in the top navigation menu.
Locate the “Security Level” label and select the option “I’m Under Attack” in the drop-down menu.
When the Security Level has been set to “I’m Under attack” the site will temporarily display to a site visitor that there are additional checks being processed and will direct them to the site if CloudFlare determines that they are safe to allow through.