The GNOME NetworkManager Applet [LWN.net]

Every once in a while, your author stumbles across a really useful piece of software. It all started when I decided to do some experimentation with 802.11g wireless networking. I procured a Linksys WRT54G-v4 router, borrowed a Windows XP box to get the router going, connected it to my LAN and was "on the air". This router happens to allow uploading of open-source firmware, I plan on experimenting with that after I become comfortable with the technology in its native state. [NetworkManager]

The other end of my limited wireless network involves a desktop PC with a D-Link Air Plus Xtreme G DWL-G520 wireless card and a Hawking Technology directional antenna with 7db of gain. The antenna is an optional accessory that is useful for extending the range of the wireless connection. The desktop machine also has a wired 100-T ethernet card. The remote machine is running the Ubuntu "Breezy Badger" (5.10) distribution and the GNOME desktop.

Ubuntu is fairly new to me, and I decided to see how far one could get with the GUI-based networking tools. I was able to simply plug in the D-Link card to the machine and boot, the card was auto-detected. In a similar experiment with a Fedora Core 4 system, the card was not detected.

The GNOME network configuration tool is fairly straightforward, just click on the desired wireless interface and tweak the properties. It is sufficient for connecting the machine to a single wireless network, but becomes painful when experimenting with connections to multiple networks. Switching to a different network involves several minutes of waiting, and the signal strength information is missing.

I want to be able to rotate my directional antenna in order to get the best signal on distant networks. The wireless-tools package contains the command line utility iwlist, which dumps out a bunch of information for each network that is in reception range. This can be useful for finding basic signal strengths, and seeing which channels are in use in your area. I configured my Linksys box to work on an unused channel.

Enter NetworkManager. The Ubuntu package description for NetworkManager says:

NetworkManager attempts to keep an active network connection available at all times. It is intended only for the desktop use-case, and is not intended for usage on servers. The point of NetworkManager is to make networking configuration and setup as painless and automatic as possible. If using DHCP, NetworkManager is _intended_ to replace default routes, obtain IP addresses from a DHCP server, and change nameservers whenever it sees fit.

[local nets] In other words, NetworkManager provides a higher level system on top of the existing network utilities. It also provides a useful desktop applet for displaying connection information and switching between networks.

To connect to a wireless network, just left-click the mouse on the network manager applet, and pick a network from the available list. Right clicking the applet brings up a list of configuration options. My neighborhood has an ever-changing number of wireless networks, most of them are configured with keys, a few of them are wide open. Keyed networks require you to enter the appropriate pass phrase.

After the network has been selected, the NetworkManager applet lights up one, then two virtual LEDs to signal the steps in the connection process. A progress bar and a fun spinning comet are also displayed in the applet while connecting. Networks with weak signal strengths will not connect, and both virtual LEDs will not light up. Eventually, the connection attempt will time out and the applet will display a not-connected icon. Unlike the GNOME network configuration tool, NetworkManager allows you to quickly abort a connection that is not succeeding, and switch to another one.

Once you successfully connect to a network, the applet icon will change into a set of four signal strength bars, these change up and down with the signal strength. Placing the mouse over the applet also displays a numerical signal strength value, I leave my mouse in this position and slowly rotate the antenna for best results.

NetworkManager has the ability to detect and auto-switch to a wired ethernet. This makes it especially useful for laptop users who frequently move between home, work and the internet cafe.

Areas for improvement

While very useful, NetworkManager is also fairly experimental software. The documentation is currently very sparse. It took a significant amount of digging to figure out how to get the nm-applet to show up on the desktop. (Hint: System->Preferences->Sessions->Startup Programs->Add).

The signal strength display can be used for optimizing the antenna direction, but it is just slow enough to make this process painful. The update time is in the order of several seconds. This may be a limitation of the hardware. It would be nice if the channel number was displayed in the list of networks. Playing with the GNOME network configuration tool while NetworkManager was running caused my machine to hang, this isn't too surprising considering the various processes that are contending for the same resources, but it is nonetheless a "bad behavior".

NetworkManager scores highly as a functional tool for automating the process of switching between wired and wireless networks, your editor plans on keeping this application around.

Addendum: RedHat Magazine published a very informative article in January of 2005 entitled Introducing NetworkManager.

(Log in to post comments)

The GNOME NetworkManager Applet

Posted Jan 26, 2006 7:51 UTC (Thu) by jayavarman (subscriber, #19600) [Link]

NM rocks! :-)

More seriously though, it's odd you found about NM in an ubuntu box instead of a fedora one (from your articles I deduce you're mostly a fedora user?) since NM is mostly developed by Red Hat people and has been working on fedora for quite some time.

Anyway, NM is on a completly different league than the GNOME networking tools, since NM is a dbus daemon (and a pretty GUI applet) which is supposed to manage all your network connectivity. Actually the plan AFAIK is for NM to be _the_ networking configuration tool (and API) on GNU/Linux systems including PPP conections and VPNs. It is an important infrastructure block that is needed yesterday. Eventually (when it is robust enough) I guess it might even be used on servers (w00t? an unix server with point-and-clik networking configuration, the windows crowd will flock onto linux :-).

A new 0.6 version I guess is near release and it will have initial support for WPA encrypted wifi networks, yay!

Yeah, this post is mostly hype but this is a project that is really worth it. Kudos to all the NM contributors!

The GNOME NetworkManager Applet

Posted Jan 26, 2006 9:13 UTC (Thu) by boudewijn (subscriber, #14185) [Link]

I use kwifimanager for the wireless stuff. It's not complete or even very
pretty, but quite functional enough for my uses.

The GNOME NetworkManager Applet

Posted Jan 26, 2006 19:28 UTC (Thu) by vondo (guest, #256) [Link]

I can't seem to get kwifi (on Mandriva 2006) to remember my networks. I connect to two networks that don't broadcast the SSID. Both windows and Palm OS put those in the SSID list and try to connect to them when they can't find a network. I can't get KWifi to do the same thing.

The GNOME NetworkManager Applet

Posted Jan 26, 2006 13:35 UTC (Thu) by jayavarman (subscriber, #19600) [Link]

The NM daemon itself is completly desktop independent. As such user GUIs to control it can be built independently. It seems someone at SUSE is working on a KDE part:

http://mail.gnome.org/archives/networkmanager-list/2005-N...

The GNOME NetworkManager Applet

Posted Jan 26, 2006 13:43 UTC (Thu) by ecureuil (subscriber, #3507) [Link]

The KDE hacker Kevin Ottens plans to add a KDE frontend to the Gnome
Network Manager.

http://ervin.ipsquad.net/index.php/2005/09/22/34-network-...

Bind9 dependency

Posted Jan 26, 2006 17:08 UTC (Thu) by pkern (subscriber, #32883) [Link]

At least on Dapper Drake (the upcoming release) there is no such dependency, and it's a matter of `apt-get install network-manager' and adding it to the startup programs as suggested by the editor.

Bind9 dependency

Posted Jan 27, 2006 13:39 UTC (Fri) by cortana (subscriber, #24596) [Link]

Presumably bind9 is configured to forward all queries to the DNS servers specified by NetworkManager.

Since programs only read /etc/resolv.conf when the are started, this was presumably necessary to allow a system to connect to a different network without having to restart all programs. I wonder what changed in Dapper...

Bind9 dependency

Posted Jan 29, 2006 18:05 UTC (Sun) by tkeitt (guest, #34685) [Link]

That's good to hear. Was just traveling with NM installed and it works very well. I did notice it has some problems with suspend-resume cycles and turning the radio on and off. Otherwise a huge improvement.

The GNOME NetworkManager Applet

Posted Jan 29, 2006 5:25 UTC (Sun) by obobo (guest, #684) [Link]

At least some Linksys routers rely on IE-only JScript for their web configuration pages. Yes, its kinda sad that a router that is running Linux requires a Windows box to admin it.

The GNOME NetworkManager Applet

Posted Jan 29, 2006 11:55 UTC (Sun) by carcassonne (guest, #31569) [Link]

Moreover for large-enough devices that can host a simple http server. There's no need then to have a Windows/IE-only path to configuration.

At least the Linksys WRT54GS I bought last year has a direct way to configure it through the web pages it serves and now I can say that it's the same for the Linksys network storage unit NSLU2 I bought last week.

Since both of these devices runs Linux, it is no surprise that both has Linux alternatives (and many alternate packages to run) one can use. For the NSLU2 there's unslung/OpenSlug (with some 6697 packages available ! - I still think they made a typo with the number and/or that there's a catch somewhere) and for the WRT54GS there's at least OpenWRT.

Both of these adds to the devices quite a few possibilities and uses. Nice little under-$100 projects for sure, that also can be useful for corporate environments.

NSLU2 packages

Posted Feb 3, 2006 11:23 UTC (Fri) by massimiliano (subscriber, #3048) [Link]

Certainly it depends on the enabled package feeds, but just now I typed "ipkg list | wc" on my beloved NSLU2 running OpenSlug, and got 5529 lines.

So the 6697 figure is not that wrong, it certainly depends on the feeds you use.

And btw, I strongly recommend the NSLU2 if you need a cheap and versatile server at home, which will not be noticed on your electricity bill even if you keep it on line 24/7 :-)

NSLU2 packages

Posted Feb 4, 2006 2:43 UTC (Sat) by carcassonne (guest, #31569) [Link]

To be fair, I think the list should boil down to:

ipkg list | grep -v locale | grep -v unicore | wc -l

For instance, I've installed Perl quite a few times (Perl standard distribution) and there were none of these unicore single packages. In fact, CPAN turns out almost nothing on 'unicore'. Why are all those little packages present under Perl in the ipkg list for the NSLU2, I don't know. Maybe this has to do with building for this type of CPU architecture.

Still, there's a lot of packages available. Next, I'll try emacs ;-)