Follow these steps if you have Windows XP Pro or Media Center Edition. This automatically configures internet sharing and automatic IP assignment to clients (dhcp).
Note : Your ad-hoc wireless network should be up and running prior to doing this. Let us start..
1. Select Network Setup Wizard either from Control Panel or from Control Panel > Network Connections
2. Network Setup Wizard opens, Keep clicking on next till the following screen shows up.
3. Select the first option as you are the host and all the other devices are on the network are going to access the internet through you. Click Next
4. Select the ethernet port directly connected to the internet. In my case its the PPPOE connection. In many of your cases, Local Area Connection would be the preferred choice.
5. Select the port/connection that connects to rest of the devices on your network. In our case, we have used the Wireless LAN to create an ad-hoc network and connect to other devices on the network.
6. Enter your host computer's name and description.
7. Enter a Workgroup name. When you chose later to switch on file and printer sharing, the workgroup settings are a must.
8. If you also wish to use the network to share files and printer, chose the first option. If you only want to share internet, select the second option.
In my case, I want to share files on the network as well.
9. Summary of all your selections are displayed. Afer verifying them, click Next
10. The Wizard starts configuring your home network. Sit back and relax for a while.
11. We are almost done. Windows will ask you how you wish to configure the clients not running XP. Select the last option and click Next.
12. Congrats. You have successfully configured your home network. Internet will be shared among all your clients connected to your pc via the ad-hoc wireless network.
Observe in your client machine (Centrino Laptop/Ubuntu in our case) all network settings are auto configured - IP, DNS, Gateway et. Filesharing is also on with the host (192.168.0.1)
Hope you liked the above tutorial. Happy Surfing !!