Default-free zone

In Internet routing, the default-free zone (DFZ) is the collection of all Internet routers that do not require a default route to route a packet to any destination, most commonly at the core of autonomous systems. Conceptually, DFZ routers have a "complete" Border Gateway Protocol table, sometimes referred to as the Internet routing table, global routing table or global BGP table. However, internet routing changes rapidly and the widespread use of route filtering leads to not every router having the same view of all routes. Any routing table created would look different from the perspective of different routers, even if a stable view could be achieved.