In the context of the Internet and BGP routing, DFZ – commonly known as Default Free Zone – refers to the collections of all the public IPv4 BGP prefixes without default route on the global Internet.
Most of the time, you hear full-route or full-Internet-route terms which are the same with Default Free Zone term. Having all BGP routes, which are announced by all the available AS (Autonomous System), on the Internet.
Currently, there are more than 600,000 IPv4 BGP routes and about 30,000 IPv6 routes in the DFZ (Default Free Zone). These numbers, however, could easily be reduced to 300,000 for IPv4 and less than 20,000 for IPv6 based on the CIDR reports (IPv4 CIDR report and IPv6 CIDR report). Read more