Enabling traffic filtering in Cloudflare

Detailed information on working with Cloudflare is available in official documentation.
  1. Connect domain to Cloudflare.
  2. Open the section «Overview»:
  3. Turn on the mode «Under Attack Mode» (enable this mode only if you really need to filter traffic):Pressing the switch again will allow you to select the appropriate filtering level.

You can change domain DNS records and enable/disable filtering for individual records in the section «DNS»: