Use the following command to configure a default route on the gateway router:
Gateway(config)#ip route 0.0.0.0 0.0.0.0 200.165.199.1
Gateway(config)#
Verify your configuration
Gateway#show ip route
[Output omitted]
Gateway of last resort is 200.165.199.1 to network 0.0.0.0
10.0.0.0/30 is
subnetted, 1 subnets
C 10.10.11.0 is
directly connected, Serial0/0/0
172.16.0.0/24 is
subnetted, 1 subnets
S 172.16.10.0
[1/0] via 10.10.11.2
C 192.168.30.0/24
is directly connected, FastEthernet0/0
S* 0.0.0.0/0 [1/0]
via 200.165.199.1
HQ#
You can check the routing table using the show ip route command as above, you
will find directed connected networks plus the S*, this shows the entry for the
default route. you can also notice that the gateway of last resort is now set in the routing table as shown above.
What the default network invariably saying is to forward any packet for an unknown network out 200.165.199.1, which is the next hop router.