Re: Network Manager and Ad Hoc Networks

[Dan Williams <dcbw redhat com>]

On Wed, 2008-03-26 at 07:20 -0800, Harold Hallikainen wrote:
> Is there more documentation on use of Network Manager on Ad Hoc networks?
> NM is working GREAT for me on managed networks, but when I try to connect
> to an existing Ad Hoc network, I see the following in /var/log/messages on
> my Fedora 8 system:
> 
> Mar 25 14:30:10 localhost NetworkManager: <info> Activating device wlan0
> Mar 25 14:30:10 localhost NetworkManager: <info> Activation (wlan0) Stage
> 1 of 5 (Device Prepare) scheduled...
> Mar 25 14:30:10 localhost NetworkManager: <info> Activation (wlan0) Stage
> 1 of 5 (Device Prepare) started...
> Mar 25 14:30:10 localhost NetworkManager: <info> Activation (wlan0) Stage
> 2 of 5 (Device Configure) scheduled...
> Mar 25 14:30:10 localhost NetworkManager: <info> Activation (wlan0) Stage
> 1 of 5 (Device Prepare) complete.
> Mar 25 14:30:10 localhost NetworkManager: <info> (wlan0) Supplicant
> interface state change: 7 -> 0
> Mar 25 14:30:10 localhost NetworkManager: <info> Activation (wlan0) Stage
> 2 of 5 (Device Configure) starting...
> Mar 25 14:30:10 localhost NetworkManager: <info> Activation
> (wlan0/wireless): connection 'Auto hh' requires no security. No secrets
> needed.
> Mar 25 14:30:10 localhost NetworkManager: <info> Config: added 'ssid'
> value 'hh'
> Mar 25 14:30:10 localhost NetworkManager: <info> Config: added 'mode'
> value '1'
> Mar 25 14:30:10 localhost NetworkManager: <info> Config: added 'key_mgmt'
> value 'NONE'
> Mar 25 14:30:10 localhost NetworkManager: <info> Activation (wlan0) Stage
> 2 of 5 (Device Configure) complete.
> Mar 25 14:30:10 localhost NetworkManager: <info> Config: set interface
> ap_scan to 2
> Mar 25 14:30:10 localhost NetworkManager: <info> (wlan0) Supplicant
> interface state change: 0 -> 2
> Mar 25 14:30:10 localhost NetworkManager: <info> (wlan0) Supplicant
> interface state change: 2 -> 3
> Mar 25 14:30:25 localhost NetworkManager: <info> (wlan0) Supplicant
> interface state change: 3 -> 0
> Mar 25 14:30:25 localhost NetworkManager: <info> (wlan0) Supplicant
> interface state change: 0 -> 2
> Mar 25 14:30:25 localhost NetworkManager: <info> (wlan0) Supplicant
> interface state change: 2 -> 3
> Mar 25 14:30:35 localhost NetworkManager: <info> Activation
> (wlan0/wireless): association took too long, failing activation.

So here's the problem; it's likely a driver issue.  The driver may be
buggy and not sending an association event when it brings up the Ad-Hoc
BSS.  I assume you've got another computer that is the source of the
adhoc BSS and are trying to get this machine to join it?

Which driver is this, and what kernel version do you have installed?

> Mar 25 14:30:35 localhost NetworkManager: <info> Activation (wlan0)
> failed for access point (hh)
> Mar 25 14:30:35 localhost NetworkManager: <info> Marking connection 'Auto
> hh' invalid.
> Mar 25 14:30:35 localhost NetworkManager: <info> Activation (wlan0) failed.
> Mar 25 14:30:35 localhost NetworkManager: <info> Deactivating device wlan0.
> 
> 
> Also, in an Ad Hoc network, how are IP addresses typically assigned?

By default, in your situation, NM will acquire an IPv4 Link-Local
address based on a hash of your MAC address, in the 169.254.x.x/16
range.  This is standard IPv4 LL assignment and allows two machines that
don't have a router to talk to each other.

> Previously, I've gone to each machine and entered a static IP. Really a
> pain, and not very "Ad Hoc." Is there a way of automatically getting an IP
> address and letting other machines on the network know what that is?

IPv4 LL (or IPv6 LL) should work just fine here; Macs do this all the
time.  However, I'm going to be changing the behavior of NM in the near
future to try DHCP on Ad-Hoc connections unless you've specified AutoIP,
though there's some room to tweak that behavior.

Dan