Default-Free Zone

From NANOG

This is the set of all Internet networks who operate without a default route.

Deaggregation greatly affects default-free networks, as all the prefixes in the global routing table must be carried by one or more routers in their network.

Generally, these networks are well peered, but that isn't relevant to the presence or absence of a default route. Neither does this appelation imply any particular geographic scope, transit status, or the like.

Most end-user networks have a default route to their ISP because the ISP is considered to be upstream from the end-user network and therefore have a limited set of choices regarding traffic handling.