RE: Issue with Auto eth0

[Dan Williams <dcbw redhat com>]

On Wed, 2009-04-08 at 14:36 -0500, Hooker, Jonathan wrote:
> It was. The problem was that we don't use the MAC address because we are creating an image off of this configuration so we want the network manager to be smart enough to look for the actual device and identify it without the MAC address. We can not use the MAC address because it would be replicated across all of the Linux machines across the network. 

The problem here is that nothing other than a MAC address or a USB
serial number that is a stable UUID of the device.  Nothing.  Relying on
device name  or position on the bus doesn't work because those things
change based on kernel enumeration or hotplug or whatever.  You cannot
guarantee that a certain device will always have the same device name or
bus position, thus you must use the MAC as there is no other unique
identifier of the device.

Dan

> 
> Jonathan Hooker
> Desktop Support - Engineering
> Garmin International
> Office: 913-440-2767
> Helpdesk: 913-440-2000 or x2000
> jonathan hooker garmin com
> 
> -----Original Message-----
> From: Dan Williams [mailto:dcbw redhat com] 
> Sent: Wednesday, April 08, 2009 10:34 AM
> To: Hooker, Jonathan
> Cc: Tambet Ingo; networkmanager-list gnome org
> Subject: RE: Issue with Auto eth0
> 
> On Fri, 2009-04-03 at 02:51 -0500, Hooker, Jonathan wrote:
> > Ok, thanks! One more question... My developers use a usb ethernet connection to connect to their development devices. Is there any way to tell NM to default to eth0 always and when the usb0 gets plugged in to automatically connect to it as a second ethernet connection?
> 
> nm-system-settings should also pick up existing ifcfg files in /etc/sysconfig/network-scripts.  Was that not happening for you?
> 
> Dan
> 
> > 
> > Jonathan Hooker
> > Desktop Support - Engineering
> > Garmin International
> > Office: 913-440-2767
> > Helpdesk: 913-440-2000 or x2000
> > jonathan hooker garmin com
> > 
> > -----Original Message-----
> > From: Tambet Ingo [mailto:tambet gmail com]
> > Sent: Friday, April 03, 2009 2:33 AM
> > To: Hooker, Jonathan
> > Cc: networkmanager-list gnome org
> > Subject: Re: Issue with Auto eth0
> > 
> > 2009/4/3 Hooker, Jonathan <Jonathan Hooker garmin com>:
> > > Hi,
> > >
> > > I am a system administrator for a large (300+) fedora desktop 
> > > environment and am in the process of creating a new image to deploy 
> > > to all of my developers. I have been having issues with setting up 
> > > NM to connect properly to our dhcp servers so that we can configure 
> > > forward dns lookups. Basically what I have done is create an Auto 
> > > Ethernet connection which has the following gconf settings:
> > >
> > >  /system/networking/connections/1/ipv4:
> > >   routes = []
> > >   addresses = []
> > >   method = auto
> > >   dhcp-hostname = testd63fed
> > >   dhcp-client-id = nixdns-testd63fed
> > >   dns-search = [garmin.com,ad.garmin.com,nix.garmin.com]
> > >   name = ipv4
> > >   dns = []
> > >  /system/networking/connections/1/802-3-ethernet:
> > >   name = 802-3-ethernet
> > >   duplex = full
> > >  /system/networking/connections/1/connection:
> > >   id = Auto Ethernet
> > >   timestamp = 1238728735
> > >   type = 802-3-ethernet
> > >   uuid = 2d204a05-4c70-4080-ad23-34b53d5a95fe
> > >   name = connection
> > > The problem is that this does not by default start when the system 
> > > does. I have also tried putting these settings in the root user's 
> > > gconf. Is there any way I can tell Network Manager to by default 
> > > select Auto Ethernet as opposed to the standard System eth0? I know 
> > > that System eth0 pulls from my ifcfg-eth0 scripts but there is no 
> > > way I can tell of sending the dhcp-hostname and dhcp-client-id back 
> > > to the dhcp server without using this or dhclient. I would really 
> > > like for all of my network device settings to be managed from the same program. Any suggestions would be greatly appreciated!
> > 
> > NetworkManager has two types of setting providers: User settings (from gconf, available only while the user is logged in) and System settings (always available). System settings have different sources (plugins) that allow taking configuration data from multiple sources (distro specific shell script setups, NM's own store, ...). The problem with supporting these different sources is that they never match one to one with NM - Missing variables, extra variables, variables with slightly different meanings, ...
> > 
> > So you'll want a "System setting" with NM's own store. Here's how you can do it:
> > 
> > * Modify /etc/NetworkManager/nm-system-settings.conf file's [main] section, 'plugins' keyword so it only has "keyfile" (NM's native settings storage):
> > plugins=keyfile
> > 
> > That'll make sure you have a writable plugin and the distro one (which doesn't provide all the options you require) doesn't interfere. Put that changed configuration to your deployment image.
> > 
> > * Restart nm-system-settings by issuing 'sudo killall nm-system-settings'. NetworkManager will restart it automatically.
> > This step is needed to make the system settings provider use the new configuration from step 1.
> > 
> > * As any logged in user, open the connection editor (nm-applet's right-click menu, Edit Connections...), create the configuration you'd like to use, and check "Available to all users". The last step is important, that's the switch between User connections and System connections. You want system connection, aka available to all users.
> > 
> > This last step will create a configuration file in /etc/NetworkManager/system-connections/ directory that contains all the connection information. Put that to your deployment image.
> > 
> > With these settings, NetworkManager will activate the connection on system boot, before any user is logged in, using all the settings known to NM.
> > 
> > Tambet
> > 
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> > 
> > Thank you for your cooperation
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