static routing refers to routes to destinations being listed mannually or statically in the router ,as the name implies.network reachability in this case is not dependent on the existence and state of the destination network itself.whether a destination is active or not,the static routes remain in the routing table,and traffic is still sent toward the specified destination.
default routing refers to a“last resort”outlet.traffic ro destination that is unknown to the router is sent to that default outlet.default routing is the easiest form of routing for a domain connected to a single exit point
dynamic routing refers to routes being learned via an interior or exterior routing protocal.network reachability is dependent on the exitence and state of the network.if a distination is down,the route disappears from the routing table,and traffic is not sent toward to the destination.