Default Route

Note :
You can configure or use default routes to direct packets addressed to destinations or networks not found in the routing table. 
This is more workable in a stub network (networks with one exit path).
To configure a default route, you will use wildcards in the network address and mask.
Using default route helps to reduce the complex work of configuring all the assigned routes.


R1(config)#do sh run | s route
ip route 0.0.0.0 0.0.0.0 10.1.12.2

Verify the Default Route

R1(config)#do sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is 10.1.12.2 to network 0.0.0.0

     1.0.0.0/24 is subnetted, 1 subnets
C       1.1.1.0 is directly connected, Loopback0
     10.0.0.0/24 is subnetted, 1 subnets
C       10.1.12.0 is directly connected, FastEthernet0/0
S*   0.0.0.0/0 [1/0] via 10.1.12.2

Testing to destination
R1#ping 2.2.2.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/77/124 ms

R1(config)#do ping 3.3.3.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 48/76/144 ms

Tracing the route to destination network 3.3.3.3
R1#traceroute 3.3.3.3

Type escape sequence to abort.
Tracing the route to 3.3.3.3

  1 10.1.12.2 96 msec 96 msec 40 msec
  2 10.1.13.3 116 msec 40 msec 40 msec