network manager has gone crazy

[Tim]

Tim:
> > _EXACTLY_ how are you giving it the data?

Lee:
> I was using system-config-network and editing some files when it didn't
> work.

Well, unless things have changed, then you're fighting two things
against each other.

System-config-network directly controls the network settings.
NetworkManager does whatever it does, dynamically.

NetworkManager will clobber settings set elsewhere, unless you
specifically configure NetworkManager to leave them alone.  You'd need
to that through NetworkManager's own interface, or through the
configuration files that it pays attention to.

> > * Are you configuring network manager, through its own interface?

> I thought system-config-network is the interface for it.  Now my theory
> is that it is perhaps not and that networkmanager conflicts with it.

It isn't.

> Where does networkmanager store it's configuration? 

I can never remember.  And the lack of useful documentation doesn't
help.

> How do you configure it?

If using Gnome, there's a desktop taskbar icon for NetworkManager, it
lets you pick a network out of a list of available networks (if there
are several to choose from), and there's an edit connections menu item
to customise particular choices.  They could be fully automatic (the
client is remotely set by a DHCP server), or you can choose to allow
some things to be set by a DHCP server, other things to be manually set,
or everything manually set.

That said, prior experience has shown that NetworkManager is geared
towards automatically configuring DHCP clients by the DHCP server.  If
you don't have a DHCP server, it can be easier to disable
NetworkManager, and use the old system-config-network, rather than try
to set up manual configurations through NetworkManager.  I do not know
if this situation has changed.

If you do not use DHCP, then I'm not sure how, nor why, NetworkManager
would be fiddling with things.  Other than, perhaps, automatically
assigning a random link-local address to the ethernet interface, because
no DHCP server assigned one.

-- 
[tim at localhost ~]$ uname -rsvp
Linux 3.6.6-1.fc17.x86_64 #1 SMP Mon Nov 5 21:59:35 UTC 2012 x86_64

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