default-free zone
jargonnetworkingISP & telecom
The part of the internet whose routers carry the full routing table and no default route - nowhere to forward blindly.
In the DFZ, every destination must be explicitly known or it does not exist - close to a million IPv4 prefixes and growing. Being default-free is what separates the core from the customers; everyone else can shrug and point a default at their provider.
Also known as: DFZ