Hello , I have started to write a HOWTO about connecting GNS3 lab to the internet on my blogger.com account.
Here is the link:
xblain.blogspot.com

Windows7\XP

Goal to achieve:

Make connectivity between two workstations in different networks. Emulated environment include:
Cisco 3600 Router, Windows Server 2003, Windows XP.

In this tutorial I will explain how to setup a network with emulated virtual PC`s using GNS and VirtualBOX.
Although the entire configuration of GNS and VirtualBOX is out of scope of this tutorial I will briefly go through the major points.

My topology is going to look like this:

Let`s start…
So the steps are next:

1. Configure VirtualBOX settings
2. Configuring GNS3 settings
3. Test connectivity

Configure VirtualBOX settings

After installing VBOX emulate 2 PC`s. I will use Windows Server 2003 and Windows XP.
To do it select NEW button from the toolbar and go through the wizard to install the required OS. You will need the images of the operation systems.

virtualbox toolbar menu

Before the emulated OS is started chose the platform from the list and click the SETTINGS button from the toolbar. Settings window will be opened. Choice Network and set the configurations as it shown in the next picture.

Do it in both emulated stations.

Configuring GNS3 settings

You will need the Cisco IOS image, it is not (and will not be) provided by GNS.

Open a new project in GNS3 and save it to your default working directory. By the way, here is a tip to make GNS working: Make sure that the path to your working directory is set in properties of Dynampis settings (Ctr+Shift+P). The folder should be created by you; otherwise the Dynampis will fail to start.

Drag and drop a Cloud from the list to the working desk. (You can configure an PC icon to have the cloud characteristic by adjusting it in Symbol Manager under the Edit menu)

Double click on your cloud and go to NIO Ethernet tab. Here are all of your installed adapters listed. Choice the VirtualBox Host-Only Network and click the Add button. Click OK. Rename the cloud by right clicking on it and selecting Change the hostname. Rename it to XP.

Do it twice , the second cloud rename to Server2003.

Emulating cisco router

I will use Cisco 3600 Router.
Drag and drop one to the working desk.
Double click on it and add, in Slots tab, two Fast Ethernet interfaces.
Click OK , then right click on your router icon and select Start

Now go to Console of the router, by right clicking on its icon and selecting Console from the drop down menu. Configure the interfaces. One with 192.168.56.254 /24 and the other with 172.30.30.254 /24

Now you have two different networks.
Add a Manual links (as shown in the next picture) between the router interfaces and the clouds.

Start your virtual machines. After each one started configure their IP addresses:

In 192.168.56.0/24 network with IP 192.168.56.1, mask 255.255.255.0, default getaway 192.168.56.254
In 172.30.30.0/24 network with IP 172.30.30.1, mask 255.255.255.0, default getaway 172.30.30.254

Test connectivity

Test your connectivity by pinging the default getaway and the other machine from each PC.
Now you can configure VTC access to your router and telnet it from the machines, or test the ACLs and etc…

That’s all, hope it will help in your learning.