usability: unplugged ethernet cable on an office desktop

[Andrew Ziem]

I hope my two cents here is what the Fedora Usability Project is looking 
for.


For office desktop users, there are several usability issues with the 
old "ethernet cable is unplugged" problem.  These problems affect a 
"normal" Fedora Core 5 office computer that uses ethernet, DHCP, NIS 
(for authentication), and NFS (especially for users' home directories).  
Some of the problems also affect (a) home users and (b) situations where 
the cable is plugged in but the network services are unavailable.

1. If the computer starts with the cable unplugged, then there's a 
start-up message like "Determining IP information for eth0:.  Failed or 
link not present.  Check cable?" First, some people may not read it 
because the startup messages are a bunch of technical mumbo-jumbo.  
Second, some people may be getting a cup of coffee instead of watching 
the screen during (long) startup process. 

2. If the ethernet doesn't work at startup, it dies forever.  If I plug 
in my ethernet cable some time later after startup, nothing happens. 
Even if the user can figure out the problem, it seems the user has to 
have root privileges to do "service network restart" to get the network 
back up.

3. If ypbind can't connect at startup, it just dies forever.  Even if 
the user can figure out the problem, it seems the user has to have root 
privileges to do "service ypbind restart".

4. If NFS mounting fails at startup, it stays unmounted until manually 
mounted.  Even if the user can figure out the problem, it seems the user 
has to have root privileges to do mount the directories.  Though there 
is a setting in /etc/fstab to allow users to mount directories without 
root privileges, it also allows them to unmount the directories.

5. If a user tries to log in when the system is suffering from the above 
problems, GDM just tells him his username or password is incorrect.  
This error message is misleading: the more fundamental problem is 
related to networking.


Based on these problems, here's what would reduce confusion, eliminate 
help desk calls, and make people happy:

1. If the network cable is unplugged and the system requires networking 
for authentication (NIS), then display a warning in GDM.

2. Better yet, cache authentication from ypbind.  Supposedly, there are 
ways to do it, but the only way it's ever worked for me is to configure 
the system as a slave NIS server.

3. If the user is already logged in when the ethernet network goes down, 
display from the system tray using the new pop-up notification system in 
Gnome 2.14.  Also, a system tray icon may be helpful if the user is away 
from his desk when the problem happens.

4. If the DHCP server/NIS server/NFS server is unavailable when the 
system starts but is available later, the system should do something 
roughly equivalent to "service network restart; service ypbind restart" 
and then mount NFS drives.  Basically, DHCP, ypbind, and NFS mounts 
should be more resilient.


As a quick competitive analysis, a Windows 2000 system does not suffer 
any of these problems while not requiring any extra configuration.


Andrew