Re: Connection sharing

[Dan Williams <dcbw redhat com>]

On Sun, 2008-12-14 at 16:18 +0100, Simon Schampijer wrote:
> Bill Moseley wrote:
> > On Fri, Dec 05, 2008 at 05:19:33PM -0500, Dan Williams wrote:
> >> On Thu, 2008-12-04 at 21:12 -0800, Bill Moseley wrote:
> >>> I'm running Ubuntu 8.10 on a Thinkpad T60p w/ Atheros wireless.
> >> madwifi or ath5k?  Only ath5k is supported, because madwifi isn't in the
> >> upstream kernel.  NetworkManager only supports drivers that are shipped
> >> in the official Linux kernel.  Since we cannot fix binary drivers, and
> >> out-of-tree drivers are of questionable interoperability and quality,
> >> they are not supported.
> > 
> > I thought I was running madwifi, but according lsmod ath9k is loaded.
> > 
> >> Is there a checkbox next to the wifi network you just created?  The icon
> >> will show your *primary* internet connection, i.e. the one you are
> >> sharing.  But the menu will also indicate the connection which is
> >> sharing your primary connection.
> > 
> > No check box -- a radio button, yes, if that's what you mean.
> > 
> >> The sharing capability requires dnsmasq-base (on Ubuntu).
> > 
> > Yes, installing that package was all it took. Very nice!
> > 
> > To disable the ad-hoc network should I just select another wireless
> > from the drop-down (or I guess I could just disable wireless all
> > together).
> > 
> > One thing that seems different since upgrading to 8.10 is that the
> > wireless always connects even when on the wired LAN.  IIRC, before
> > nm-applet would stop the wireless when I connected to the wired LAN.
> > But, my memory might be wrong about that.
> > 
> >> If you
> >> install that, when you "create new wireless network", it will create an
> >> Ad-Hoc wifi connection and will start dnsmasq as a forwarding nameserver
> >> and DHCP server on that adhoc network.  Other computers that connect to
> >> that adhoc network will then be able to get a DHCP address.
> > 
> > I see.  So my Thinkpad is preforming NAT (it's address is 192.168. and
> > the devices that connect to it (like my iBook) is 10.42.44.10,
> > 
> > 
> > 
> >> *however*, since you state that other computers cannot see the newly
> >> created adhoc sharing network, this either indicates that you don't have
> >> dnsmasq installed, or it indicates driver problems.  I had to fix quite
> >> a few upstream drivers along the way to get adhoc networking to work
> >> correctly, and fix wpa_supplicant in a few cases.  These changes are in
> >> released kernels (2.6.27 and later) and also in the latest
> >> wpa_supplicant releases (0.6.5 and later).
> > 
> > Thanks very much for you effort.  Very impressive how well these
> > things work now.
> 
> Yup, does work great for me as well to share my wired connection, 
> terrific work!
> 
> One thing I did not understand yet is, that once the second machine is 
> connected I do not get any information about the signal strength anymore 
> (it show up as being 0).
> 
> This is reflected in both machines in the nm-applet but as well if I 
> check with iwconfig. When I do scanning with iwlist I get the signal 
> strength information fine.
> 
> Any ideas what I miss here?

The driver is either (a) not reporting the adhoc IBSS in its scan list,
or isn't reporting signal strength for the IBSS in the scan list, or
isn't reporting signal strength at all when in IBSS mode.  It's
completely a driver problem.

I think I've said a few times before on linux-wireless@ that drivers
should be reporting 100% strength for adhoc no matter what, until we
figure something else out.

Dan