A router in the default zone (DFZ) of an internet has only explicit routes in its routing information base; it gets all routing information from local configuration and dynamic routing protocols. Its tables contain no default routes.
Internet transit providers' interprovider routers connect to the DFZ. Large enterprise edge routers that connect to multiple ISPs may be in the DFZ. Any production DFZ router will run the Border Gateway Protocol as its major means of acquiring routing information.