ntopng categorizes hosts using services are provided by http://block.si In order to use these categorization services you need to mail info@block.si and ask for a test key to be used in ntopng or go to http://www.blocksi.net/blocksi-api.php Once you have the key available, you can start ntopng -c KEY ... NOTES: - THIS IS AN EXPERIMENTAL SERVICE - NTOPNG WILL CONTACT DIRECTLY BLOCK.SI (NO TRAFFIC WILL PASS THROUGH NTOP.ORG) - NTOP HAS NO BUSINESS RELATIONSHIP WITH BLOCK.SI