Connecting GNS3 lab to the internet - Lesson1

Connecting GNS3 lab to the internet

Part1. Connecting Cisco router to the internet

Windows7\XP

Hello in this tutorial I will explain how to connect your GNS3 lab to the internet.

The HOWTO contains two parts. First - Connecting Cisco router to the internet. And second - Connecting the emulated network to the internet. 

In our situation we would connect the whole emulated networks to the internet. To achieve this we will connect one of our routers to the internet and will then use NAT on this router  to allow other emulated networks to get access outside.

My topology will looks like this:

Windows7 - The PC where the GNS3 installed and running

MSLoopback - Microsoft loopback adapter

Router - My real Edimax router

Inetrnet - Real internet

So here are the steps:

1.Create MSLoopback interface

2.Create Cloud connected to MSLoopback interface

3.Create Cisco router and connect it to the cloud

4.Test connectivity

Create MSLoopback interface

Firs off all you`ll need an Loopback adapter thru witch your emulated network will be connected to your computer.

Go to Control Panel >> Device Manager , right click on your computer name at the top of the list and select Add legacy hardware. Wizard window will open.Click NEXT and choice Install the hardware that I manually choice from the list.

Choice Network Adapters and click NEXT.

Choice Microsoft category from the list at the left side of the windows and than Microsoft Loopback Adapter.Click next. After installing a new adapter will appear at your network devices window.

I have renamed this adapter to HOST to GNS.

Now you need to allow you interface that connected to the internet to be used by other networks. In my case this is wireless adapter that connected to my Edimax router. Right click on it and select Properties, now go to the Sharing tab. Select Allow other network users to connect through this computer`s internet connection: check box, and select the Microsoft Loopback Adapter as it shown on the picture (Remember I have renamed my MSLoobpack to HOST to GNS)


Click next. At this point windows will set the IP of your Microsoft Loopback interface to 192.168.0.1 with 24 network mask.


Create Cloud connected to MSLoopback interface
Open a new GNS3 project. Drag and drop Cloud from the list to the working space. Right click it and select Configure.

In the NIO Ethernet tab select your Microsoft Loopback interface and click on Add button. Click OK. Now you have a cloud connecting your GNS project through the loopback interface to your computer.


Create Cisco router and connect it to the cloud
I will use Cisco 3600 router. Create 2 Fast Ethernet interfaces. Start the router and configure one of the interfaces (I will use FastEthernet 0/0) with IP: 192.168.0.254 /24


Configure default route by entering this command under the EXEC mode:


(config)#ip route 0.0.0.0 0.0.0.0 192.168.0.1


Connect the FastEthernet 0/0 interface to the cloud. 


Test connectivity
At this point you should be able to ping the Microsoft Loopback Interface (192.168.0.1) from the router. Also try to ping your real Router (The default getaway of your computer). And than try to ping  internet addresses. try to ping domain names like google.com


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