If you have Smartevent, utilizing a response for external IP Sweeps to block the source IP address for a time you determine works great. I would advise the first time you do enable the feature in Smartevent, enable a response with an email to you so you can see the volume and make sure you would not block legitimate sources. Using Playblocks, in the portal.checkpoint.com, they have some automations for blocking that maybe what you are looking for if you do not have Smartevent. Obviously, you would need a license for Smartevent or Playblocks.