When you block a source in ClickGuard, or one of its protection rules does, ClickGuard tells Google Ads to create an exclusion record for the affected campaigns. Google then stops showing your ads to that IP address, IP range or placement in those campaigns, until the exclusion expires or you remove it.
When an exclusion is created in ClickGuard, manually or when protection settings (rules) are triggered, ClickGuard instructs Google Ads to create an exclusion record for the affected campaign(s).
These instructions include:
In the back, ClickGuard sends a command to Google via Google Ads API and awaits for the response to confirm that the given entity is excluded.
See also: How does ClickGuard remove exclusions in Google Ads.