NetworkManager cannot open display

[80aless]

Hi,
I am writing to help my girlfriend with her suse machine and to understand myself more about linux. She can connect typing

xhost +
sudo NetworkManager

1) Is it normal to have to use sudo before NetworkManager?

2)If she omits xhost + she cannot open any display anymore, eg

sudo NetworkManager
firefox &
Invalid MIT-MAGIC-COOKIE-1 keyError: cannot open display: :0.0

In a forum they say that a solution is to put nm-system-settings.config in /etc/network
I do not have the directory /etc/network ,I do have a nm-system-settings.conf

whereis nm-system-settings.config
nm-system-settings: /usr/sbin/nm-system-settings /etc/nm-system-settings.conf

In another they speak too technical to be understandable, at least for me:

 NM is changing the hostname because you have not locked a persistent
hostname with nm-system-settings, and your hostname was 'localhost' or
'localhost.localdomain' or empty when nm-system-settings started up.  If
you had a persistent hostname set (and a system-settings plugin to parse
it) then NM should respect that hostname.
 
The issue with no X program launching is an X anachronism, where Xauth
uses the hostname as part of the authentication cookie.  When your
hostname changes, the Xauth cookie is no longer valid, and thus you no
longer have permission to talk to the X server.
 
To fix this, you have your xinit scripts tell the X server to allow all
users who have already authenticated themselves (via the display manager
like gdm or whatever) as long as that user is using unix socket
transport to connect, and is thus obviously local.  On Fedora, we added
this bit to /etc/X11/xinit/xinitrc.d/localuser.sh:
 
[ -x /usr/bin/xhost ] && [ -x /usr/bin/id ] &&
    xhost +si:localuser:`id -un` >& /dev/null 
  

3) In system>Sessions there is a

 nm-applet --sm-disable &

command, but I cannot see the applet. How to restore it, or why does the applet not start?

Thanks,
alex

[gogalthorp]

Did you set up the network via Yast? Did you select use networkmanager?? That should put an icon on your bar to access the networkmanager interface.

[80aless]

I have NetworkManager installed, if this is what you mean. Anyway
In yast>Network Settings > Global option there was Network Setup Method:
"Traditional Method with ifup", I put "User Controlled with NetworkManager".

After a reboot I get asked to type the passwrod. At that point I cannot open any application because I did not have the time to do xhost + before NetworkMaager.I still do not see the icon.

I reboot again and click 10 times on the "deny" button in order not to launch NetworkManager. After that, xhost + , sudo NetworkManager but it does not conncet anymore.

I go back to the "Traditional Method with ifup" mode and add in seesion xhost + (I see that it works not only from the terminal, but also in "session" at startup).

Any other ideas?