Re: Possible key to solution [was: Does anyone understand NetworkManager?]

[David Abrahams <dave boost-consulting com>]

"Darren Albers" <dalbers gmail com> writes:

> On 9/1/06, David Abrahams <dave boost-consulting com> wrote:
>> Is it possible this is the key to what's going wrong?  If NM doesn't
>> do the equivalent of
>>
>>   ifup eth1
>>
>> just before it starts interacting with wpa_supplicant, or if it
>> doesn't get its work with wpa_supplicant done before ifup times out
>> looking for a DHCP lease, it seems like connecting is going to fail in
>> my environment.
>
> I don't think so and the debug you posted doesn't indicate this, if
> you look at src/nm-device-802-11-wireless.c
> http://cvs.gnome.org/viewcvs/NetworkManager/src/nm-device-802-11-wireless.c?rev=1.60.2.17&view=markup
>
> You will see that it brings up wpa_supplicant and then waits for a
> successful association message before working to get an ip address.

Yes, I think that's exactly what I'm saying could be problematic.

On my system, my experience was that I need to do 

  ifup eth1

/before/ I invoke wpa_supplicant.  In other words, the attempts to get
an ip address need to begin before wpa_supplicant is started.

>> A couple of further questions:
>>
>> 1. Where does NM look for information about whether to connect via
>>    DHCP or with a static IP?  I presume it can't be
>>    /etc/network/interfaces, because I see lots of advice around to
>>    comment the interfaces managed by NM *out* of that file (although
>>    that doesn't seem to make any difference one way or the other for
>>    me).
>
> I /think/ it just brings up dhclient to obtain the information from
> the DHCP server and at this time it does not support static addressing
> on Ubuntu at all 

Oh, that's _most_ unfortunate.

> and with other distros just pulls the static info from the distro's
> ip management system.

Other distros have IP management systems?

>> 2. Once I've stopped NM, killed nm-applet, set up
>>    /etc/network/interfaces, and done ifup to activate an interface,
>>    when I try to undo that process and restart NM, it seems as though it
>>    can't see any interfaces at all.  What am I doing wrong?
>
> This is because the Ubuntu Maintainer modified NetworkManager so it
> would not manage ANY interfaces that has any configuration beyond dhcp
> in /etc/network/interfaces.

Ah.  If it will manage an interface that is specified to use dhcp,
that explains why the advice I've seen to de-configure the interface
seemed to be bogus.

> Now saying all that I have seen a number of reports of strange issues
> like what you are reporting and most of the people seem to be using
> Ubuntu or Debian.   I run Ubuntu but I build NetworkManager myself
> with only the patchs I need or want.

I would be interested in knowing more about your configuration.

> So I grabbed the Ubuntu packages and tried it out and it seemed to
> work great for me but I did notice something odd when I went to place
> my dispatcher scripts and that is that the Ubuntu and Debian packages
> both have a Dispatcher script to run ifup and ifdown.
>
> I am not sure why this is needed but I will dig around through the
> changelogs sometime soon and see why.  I think the Ubuntu Maintainer
> subscribes to this list so maybe he can help there.  It is obviously
> there for a reason but none of my laptops (One uses an IPW2200 and the
> other uses a Atheros card) need that script to function.
>
> So can you please test something, please move that script and reboot
> your laptop and see if the problem goes away?  sudo mv
> /usr/share/NetworkManager/dispatcher.d/01ifupdown /your/home/

I have to reinstall NM first, but I'll do that.

> Replace /your/home/ with the path to your home directory.

How about "~" ;-)

> Since you describe a problem with the interface obtaining an IP
> address I wonder if that script is either there to solve a problem
> or might be causing an issue.

As far as I can tell, I've had myriad different problems at different
times.  Networking in general has been utterly frustrating and
capricious for me.  A few days ago, even wpa_supplicant stopped
working for me.  When I booted this computer, I had neither wired or
wireless interfaces available; they seemed to be unknown to the
system.  Several hours of running screensavers later... there they
are!  Sheesh!

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com