I have a broadband connection on my main desktop that runs Vista, which has an ethernet port and a usb WiFi dongle. And I have HCL MiLeap-L that comes with WiFi on board. I always wanted to have internet connection sharing setup on my Vista machine so that I can access Internet anywhere from my house using MiLeap-L. Until recently, I could not figure out why the ad-hoc network created from Vista was not getting configured from the default NetworkManager applet of Ubuntu (MiLeap-L runs 8.04).
It turned out that this the problem with the default Ubuntu driver for the WiFi chipset on MiLeap-L. The default driver (supposedly a newer version) called rt73usb has buggy support for ad-hoc mode operation. So after googling around a bit I found that you need to use the legacy drivers rt73 and blacklist the newer ones to get it working. Moreover the older version is not compatible with the NetworkManager applet and you have to use its own GUI called rtutilt. So here is what I did to get stuff working:
1) I already have latest kernel update with the requisite build tools and kernel headers. If you don't you will have to get that using apt-get install kernel* build-essential.
2) Get the latest rt73 source from http://rt2x00.serialmonkey.com/rt73-cvs-daily.tar.gz
Do the following using root (sudo -s) credentials:
3) unpack, change to Module directory. Then make and make install.
4) Remove previous module: rmmod rt73usb
at the end of /etc/modprobe.d/blacklist
6) modprob rt73
7) Install rtutilt using synaptic manager (u may have to enable extra repos)
8) disable NeworkManager applet from Main Menu->System->Preferences->Sessions
9) reboot and use Main Menu -> Internet -> RutilT WAN Manager to discover and connect to access point or ad-hoc network.
Note: If at any point of time you need to upgrade the kernel, you will have to most likely recompile rt73 drivers.
Its straight forward here.
1) First enable Internet Connection Sharing (ICS) on interface to which broadband is connected, in my case this is the LAN. This automatically assigns 192.168.0.1 then to the WiFi interface. The required gateway and other settings are also automatically made.
2) Then setup a ad-hoc connection using the Connection wizard in which can be initiated by clicking the Network icon on the task bar... or better still use the Instant search!
3) Thats it!
Hope this is useful to other HCL MiLeap users who want to try similar setup.
PS: when you need to use WiFi from any other source, you need to use the RutilT GUI now instead of the NetworkManager applet in Ubuntu.
PPS: This whole stuff was written on my MiLeap-L and posted using the connection that I set up as described above :)