Networking Exam Academy

This is Lab 07 where we are going to learn about using the routing table, how to set up static routes, and verifying that everything works by pinging between all three routers. This tutorial uses Networkcraft – The Online Network Simulator to walk you through this tutorial and so that you can practice programming the routers yourself without having to install or purchasing your own equipment.

Networkcraft uses a command line interface just like what you will find in an actual Cisco router or switch. If you haven’t already worked through the previous tutorials I suggest you do so before moving on if none of this is familiar to you. Let’s begin!

This is the topology that we are going to use for this lab. We have 3 routers connected to each other. Router 2 is connect to both Router 1 and Router 2.

Below you will find the terminal windows for the 3 routers that we are going to use in this lab. Inside of these terminal windows is where you are going to be typing in the commands to configure each router. The rest of the tutorial is shown below after these terminal windows.

Router 1

Router 2

Router 3

Before we officially begin the tutorial you will most likely need to click on the “restart” link under each router to clear out any settings that still might be saved from previous tutorials.

Step 1: Configuring Router 1

The first thing we are going to do is rename the router so that we don’t confuse it with any of our other routers. To rename your router follow these steps:

Router>enable
Router#config t
Router(config)#hostname r1
r1(config)#

To rename the router we entered enable mode and then entered configuration mode. Once in configuration mode we typed in ‘hostname’ followed by the name we want to call our router, in this case ‘r1′.

Now let’s configure Router 1 with an ip address on its e0 interface.

r1(config)#interface e0
r1(config-if)#ip address 10.10.1.2 255.255.255.0
r1(config-if)#no shutdown
r1(config-if)#exit
r1(config)#exit
r1#

What we did here was enter interface mode for ‘e0′, then we typed in the ip address followed by the subnet mask, then we turned on the interface with the ‘no shutdown’ command, then we exited out of interface and configuration mode.

Step 2: Configure Router 2

We are going to do almost the exact same thing that we did for Router 1, but change the hostname to ‘r2′ and use the ip address ’10.10.1.1′. Here are the commands to do this:

Router>enable
Router#config t
Router(config)#hostname r2
r2(config)#interface e0
r2(config-if)#ip address 10.10.1.1 255.255.255.0
r2(config-if)#no shutdown
r2(config-if)#exit
r2(config)#exit
r2#

Step 3: Test Connection Between Router 1 to Router 2

To test the connection between Router 1 and Router 2 go to Router 1 and type in this ping command:

r1#ping 10.10.1.1

If everything is configured correctly your output on the command line after you scroll down should like like this:

Step 4: Test Connection Between Router 2 to Router 1

Just do double check let’s go ahead and test the connection from Router 2 to Router 1:

r2#ping 10.10.1.2

Here is a screen shot of the output that you should get after typing in the above command on Router 2:

Step 5: Configure e1 Interface on Router 2

Just like we did in step 2 we are going to configure Router 2 again, but this time we are going to configure the e1 interface instead of the e0 interface.

Follow these commands to configure the e1 interface:

r2#config t
r2(config)#interface e1
r2(config-if)#ip address 10.10.2.1 255.255.255.0
r2(config-if)#no shutdown
r2(config-if)#

The above commands configured the e1 interface with the ip address of ’10.10.2.1′.

Step 6: Configure e0 Interface on Router 3

Just like we did in the step 1 we are going to do almost the exact same thing but use interface e0 on router 3 and give it the ip address of ’10.10.2.2′. Follow these steps to configure router 3:

Router>enable
Router#config t
Router(config)#hostname r3
r3(config)#interface e0
r3(config-if)#ip address 10.10.2.2 255.255.255.0
r3(config-if)#no shutdown
r3(config-if)#exit
r3(config)#exit
r3#

Step 7: Test Connection Between Router 2 to Router 3

Now let’s ping from Router 2 to Router 3 using the ping command and the ip address ’10.10.2.2′:

r2#ping 10.10.2.2

The output of your ping command should look like the screen shot below:

Step 8: Test Connection Between Router 3 to Router 2

To double check that everything is work correctly let’s try the connection in the other direction:

r3#ping 10.10.2.1

The output of your ping command from Router 3 should look like the screen shot below:

Step 9: Try to Ping from Router 1 to Router 3

Since we have been able to verify that we can ping between r1 and r2, and from r2 to r3, let’s see if we can ping from r1 to r3.

r1#ping 10.10.2.2

This should NOT work and you should get out put like the screen shot below:

So, why doesn’t it work? Let’s take a look at our routing table to see.

Step 10: Looking at the Routing Table

To look at the routing table of one of our routers we will use the ‘sh ip route command’ which will show you the contents of your routing table.

So, on r1 type in the ‘sh ip route’ command

r1#sh ip route

The output of this command should like the screen shot below:

Please don’t get overwhelmed with the above output because we really only need to look at the very last line. The first part of the ‘sh ip route’ output just displays a list of codes. Go ahead and look for code ‘C’ and code ‘S’ because those are the codes that we are going to be using in the rest of this tutorial.

No if you look at the last line of this output you see that it begins with a ‘C’. The ‘C’ means that this is a directly connected route. The next part of this output shows the network address ’10.10.1.0′.

As you can see there is only route entry and there is no entry for the ’10.10.2.0′ network where r3 resides. To add an entry to the routing table for the ’10.10.2.0′ network perform the following command which we will cover in the next step.

Step 11: Creating a Static Route

To create a static route on r1 for the ’10.10.2.0′ network so that you will be able to ping from r1 to r3 use the ‘ip route’ command:

r1#config t
r1(config)#ip route 10.10.2.0 255.255.255.0 10.10.1.1
r1(config)#exit

There are 3 parts to the ip route command. The first part is the network you want use. The second part is the subnet mask for that network. The third part is the ip address of the next hop router, in this case this is the ip address of e0 on r2.

Now type in the ‘sh ip route’ command again:

r1#sh ip route

Now if you look at the last line of the output you will see that our static route has been added.

Now let’s configure the other static route on r3 to finish our configuration.

Step 12: Create a Static Route on Router 3

Follow these steps, just like the ones in Step 11, to set up a static route on r3 to the ’10.10.1.0′ network.

r3(config)#
r3(config)#ip route 10.10.1.0 255.255.255.0 10.10.2.1
r3(config)#exit
r3#sh ip route

Now let’s see the output of the sh ip route command that we just typed in:

As you can see from the last line of the output we now have a static route set up that goes to the ’10.10.1.0′ network via the ’10.10.2.1′ interface.

Step 13: Ping from r3 to r1

Now that we have our static routes set up we can ping all the through from r3 to r1 and from r1 to r3.

Let’s go ahead now and ping r1 from r3:

r3#ping 10.10.1.2

This is the output that you should see now:

Summary

Congratulations you just finished lab 07! Remember that we learned how to set up 3 routers and configured them to used two different networks. Since the routers were in two different networks we couldn’t ping between them until after we set up a static route.

Thanks for completing this tutorial and I hope it helps prepare you for your CCENT/CCNA Exam.

I invite you to leave a comment below if you have any questions or ideas about future labs.

Thanks,
-Blake Erickson