Other sources of routes in the routing table
The IP route table can also receive routes from
the following sources:
Directly connected networks: One route is created per IP interface. When you add an IP interface, the routing switch automatically creates a route for the network the interface is in.
RIP: If RIP is enabled, the routing switch can learn about routes from the advertisements other RIP routers send to the routing switch. If the RIP route has a lower administrative distance than any other routes from different sources to the same destination, the routing switch places the route in the IP route table.
OSPF: See RIP, but substitute "OSPF" for "RIP".
Default route: This is a specific static route that the routing switch uses if other routes to the destination are not available.