How to Configure Default Routing

We are given the above topology and we have to implement the following:

1. Create default route on ISP router to the RISE STAR Enterprise Company. 
2. Apply command show ip route to verify your configuration. 

Default Routing is very similar to the Static Routing as the pattern of configuring the Default Routing is identical to the Static Routing.

Now to start, click the ISP router and go to the CLI tab and type the following:

ISP>en

ISP#conf t

ISP(config) #ip route 0.0.0.0 0.0.0.0 se0/0/0

ISP(config) #ex

ISP#

Now click LAB_A router, go to the CLI tab and type the following:

LAB_A>en

LAB_A#conf t

LAB_A(config) #ip route 0.0.0.0 0.0.0.0 se0/0/0

LAB_A(config) #ip route 0.0.0.0 0.0.0.0 se0/0/1

LAB_A(config) #ex

LAB_A#

Now click on LAB_B router and go to the CLI tab and type the following:

LAB_B>en

LAB_B#conf t

LAB_B(config) #ip route 0.0.0.0 0.0.0.0 se0/0/0

LAB_B(config) #ip route 0.0.0.0 0.0.0.0 fa0/0

LAB_B(config) #ex

LAB_B#

Finally click on LAB_C router and go to the CLI tab and type the following:

LAB_C>en

LAB_C#conf t

LAB_C(config) #ip route 0.0.0.0 0.0.0.0 fa0/0

LAB_C(config) #ex

LAB_C#

Note that the first address(0.0.0.0) is used for the default address and the second(0.0.0.0) is used for the default sub-net mask and fa0/0 is the next hop address.

The task 1 is completed here.

Now the second task is to verify the configuration. To do this simply go to every router one by one and type the command show ip route in the CLI tab as shown below:

As you can see in the highlighted area the default routing is configured. If this line does not appear, it means you have not configured the routers correctly.