Normally, pinging a site will return the actual IP address for the site.

However, with pfBlockerNG properly setup you may instead see a reply of 10.10.10.1, which is the default blocking virtual IP address that DNSBL creates:

For sites that are allowed to get through, their proper IP address will be returned by a ping instead of 10.10.10.1:

The same goes for an nslookup query, which will also return a response of 10.10.10.1 for adverts:

For sites that are allowed to get through, their proper IP address will be returned instead of 10.10.10.1.