Default route

Without a default route, a packet that does not match any routing entries is discarded and an ICMP destination-unreachable packet is sent to the source. A default route is used to forward packets that do not match any routing entry.

The network administrator can configure a default route with the destination as and the mask as 0. The router forwards any packet whose destination address fails to match any entry in the routing table to the next hop of the default static route.