[juneau-lug] network-manager

I've been playing with wireless at home, and specifically setting up my laptop 
to browse various networks - at home with no ssid broadcast and encryption, 
as well as open networks like the library.

I had the various security settings I needed for home hardcoded into 
my /etc/network/interfaces file, but that caused trouble if I took my laptop 
somewhere else, such as the library.  I had to remove the settings manually 
or just kill them with iwconfig, which requires root access.  And before my 
Averatec died, the rt2500 drivers *hated* that without a reboot!  Now I have 
an older Vaio with a Netgear card that behaves better, even if it does need a 
firmware blob.

Enter NetworkManager.  This utility is in Debian testing now (network-manager 
and network-manager-gnome or network-manager-kde), and most likely has 
packages for your favorite distribution.  Of course source is available.  It 
is a Gnome project at http://www.gnome.org/projects/NetworkManager/ 

NetworkManager is split into two parts - a server and a user applet.  The 
server watches certain devices (essentially any network device that doesn't 
have a static or custom configuration) and attempts to keep a network 
connection alive.  It prefers wired over wireless, so if you plug a cable 
into a laptop that has a working wireless connection, you will suddenly 
switch over to the wired link.  The user applet allows a non-root user to 
control the network connection(s).  The user can disable wireless entirely, 
in which case NetworkManager disables the card.  At least on Debian, the user 
needs to be in the netdev group.

The NetworkManager applet keeps things like ssids and WEP keys in various 
wallets.  I use KDE, so of course Kwallet is used.  This means that my (as in 
my user's) wallet must be available for NetworkManager to associate with my 
WAP at home.  So my laptop gets to be kind of Windows-ish, in that if the 
wrong user or no user is logged on, an encrypted wireless connection is not 
available.

The applet scans available wireless networks and displays them in a list, 
along with their signal strength.  It won't automatically associate with a 
network unless the user has previously connected, making that network 
a "trusted" network.  So for example if you've been hanging out at the Waffle 
Company it would connect.  Then when you pick up and move to the library it 
will let you know about the new network, but won't associate with it until 
you say it is OK.  You can move networks in and out of the trusted list if 
you don't want to automatically associate somewhere that you've been in the 
past.  That's important, as an open network would not need access to anyone's 
wallet, so NetworkManager could associate without a user logged in.  I think 
that's probably fine for a wired connection, but not for wireless.

All in all, pretty cool.  I wish I could get it to automatically associate at 
home without having my user logged in.  Maybe it does that and I just haven't 
found out how to do so.  But if you've been playing with wireless and roaming 
and you haven't given it a try, it might be worth your while.  It is still 
under development -- for example, WPA is hit and miss, and at least on my 
laptop I can enter a 40 bit ASCII or hex WEP key, but if you use a 128 bit 
key you have to enter the passphrase instead.  I don't know why it won't let 
you just enter the 128 bit key -- that seems odd to me.


James
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