Happy to assist if this does not help you:
(hate to post the entire page, but straight from GNOME, this is the FAQ for Network Manager and gives a pretty good overview)
sudo yum install NetworkManager NetworkManager-gnome (or use the Applications->System Tools->Software Updater application)
Then you must enable NetworkManager to start as a system service.
sudo /sbin/chkconfig --level 345 NetworkManager on (or use System->Administration->Services and turn NetworkManager on for levels 3, 4, and 5)
Then start NetworkManager:
sudo /sbin/service NetworkManager start (or use the Services application to start NetworkManager)
Note: Network Manager is included by default in all recent Debian and Ubuntu Releases.
How do I get that nice little applet?
Under the Gnome desktop environment, the ‘nm-applet’ process should already be started when you log in. If you don’t see it, verify that it’s running by checking for a process called ‘nm-applet’. If it is running, NetworkManager may not be started. The applet hides itself when NM is not running.
If you are unable to find help anywhere please post a message to the Network Manager Mailing list at NetworkManager-list Info Page
Configuration
How do I remove networks I no longer wish to connect to?
For Version 0.6.5 or earlier From the command line run the following replacing <SSID> with the SSID of the network you wish to remove:
gconftool-2 --recursive-unset /system/networking/wireless/networks/<SSID>You can use the “Configuration Editor” (gconf-editor) to browse the networks listed in that configuration directory, but you cannot remove the SSID’s folder using the GUI tool.
For version 0.6.6 or later Use the Network Profile editor to remove unwanted networks.
How do I setup a static IP address with NetworkManager?
NetworkManager has limited support for static IP addressing. Configuration of static IPs is distribution specific and should use that distribution’s normal network configuration methods.
For example, on Fedora Core, using the system-config-network tool or editing /etc/sysconfig/network-scripts/ifcfg-eth1 to set a static IP up for the device ‘eth1’ would result in NetworkManager using that static IP configuration whenever you connect to an access point using eth1. Obviously, since static IP configuration is always a manual task, NetworkManager is not able to automate the process in any way.
Better support of static IP addresses is planned and in-progress for NetworkManager 0.7.
How do I set up VPN connections?
NetworkManager has support for three types of VPN connections; Cisco VPNs (via vpnc), OpenVPN, and PPTP VPNs (The PPTP VPN Plugin is not available yet for 0.7). (Of these, the Cisco/vpnc is the most mature, possibly because it doesn’t have so many configuration options to account for )
You must first install the VPN plugin, and then restart NetworkManager so that the plugin is recognized. You may then use the “Configure VPN…” menu item in the desktop applet to set your VPN connection up.
Fedora
sudo yum install NetworkManager-vpnc or use the Software Updater application to install it
We plan to remove the requirement for restarting NetworkManager to recognize new VPN plugins with the 0.7 version. Also, make sure you use a VPN plugin that’s compatible with your version of NetworkManager. The NM<->VPN interface was changed between NM 0.6 and NM 0.61, which may cause some plugins to fail. If this happens to you, try updating your VPN plugin.
Ubuntu
Older versions of Ubuntu (6.10 or earlier) did not include any VPN Plugins, but all releases since 2007 have all the VPN plugins available. sudo apt-get install network-manager-openvpn network-manager-vpnc network-manager-pptp
What does the “Fallback Network” Option do?
This tells Network Manager to fall back and try to connect to this network even if it does not see it by scanning, this may help people who have issues connecting to networks with “hidden” SSID’s.
How do I tell Network Manager to rescan for wireless networks?
If you click on the Applet Network Manager will initiate a scan request. In general there should be no need to do this since Network Manager scans automatically and attempts to scan in a manner that impacts the card the most.
Hardware
What wireless cards does NetworkManager support?
NetworkManager does not support any specific cards, it is designed to work with any card that supports the latest Linux Wireless Extensions (WEXT) standard. See this link for information on specific cards: NetworkManagerHardware
My Card is not recognized by NetworkManager and I am running Debian or Ubuntu:
Debian and Ubuntu modified NetworkManager so that it would not manage any devices listed in /etc/network/interfaces. If you open this file and comment out the lines for the interfaces you want to manage and reboot NetworkManager will see them. Do not comment out l0
Why does NetworkManager crash with recent versions of dbus?
This probably doesn’t apply anymore There is a known bug in dbus that causes NetworkManager to crash in certain rare cases. This bug is being worked on in dbus and a fix should be out shortly. (DBusPendingCall objects are not properly reference counted, and dbus tries to use the DBusConnection object referenced from the pending call structure after it has already been freed, leading to the crash).
Your crashlog (from /var/log/messages) will look like this:
Jun 27 11:25:18 localhost NetworkManager: <WARNING> nm_signal_handler (): Caught signal 11. Generating backtrace…
Jun 27 11:25:18 localhost NetworkManager: ******************* START **********************************
…
Jun 27 11:25:19 localhost NetworkManager:
Jun 27 11:25:19 localhost NetworkManager: Thread 3 (Thread -1219298400 (LWP 4169)):
Jun 27 11:25:19 localhost NetworkManager: #0 0x001f4402 in __kernel_vsyscall ()
Jun 27 11:25:19 localhost NetworkManager: No symbol table info available.
Jun 27 11:25:19 localhost NetworkManager: #1 0x001b1bdb in __waitpid_nocancel () from /lib/libpthread.so.0
Jun 27 11:25:19 localhost NetworkManager: No symbol table info available.
Jun 27 11:25:19 localhost NetworkManager: backtrace () at nm-logging.c:72
Jun 27 11:25:19 localhost NetworkManager: s = {st_dev = 64768, __pad1 = 0, st_ino = 1343769, st_mode = 33261,
Jun 27 11:25:19 localhost NetworkManager: st_nlink = 1, st_uid = 0, st_gid = 0, st_rdev = 0, __pad2 = 0,
Jun 27 11:25:19 localhost NetworkManager: st_size = 12110, st_blksize = 4096, st_blocks = 32, st_atim = {
Jun 27 11:25:19 localhost NetworkManager: 96, tv_nsec = 0}, st_mtim = {tv_sec = 1151086415,
Jun 27 11:25:19 localhost NetworkManager: tv_nsec = 0}, st_ctim = {tv_sec = 1151419396, tv_nsec = 0}, __unused4 = 0,
Jun 27 11:25:19 localhost NetworkManager: __unused5 = 0}
Jun 27 11:25:19 localhost NetworkManager: #3 0x0806c941 in nm_signal_handler (signo=11) at nm-logging.c:166
Jun 27 11:25:19 localhost NetworkManager: in_fatal = 1
Jun 27 11:25:19 localhost NetworkManager: _signal_handler"
Jun 27 11:25:19 localhost NetworkManager: #4 <signal handler called>
Jun 27 11:25:19 localhost NetworkManager: No symbol table info available.
Jun 27 11:25:19 localhost NetworkManager: #5 0x007de302 in check_for_reply_and_update_dispatch_unlocked (
Jun 27 11:25:19 localhost NetworkManager: pending=0x8f58ae0) at dbus-connection.c:2515
Jun 27 11:25:19 localhost NetworkManager: reply =
…
Jun 27 11:25:19 localhost NetworkManager: ******************* END
NetworkManager does not list my Realtek Gigabit Network card:
This is a known issue with the r1000 driver not supporting link status detection. This is rumored to be fixed in the 2.6.17 Kernel.
Debuging
How do I debug a connection?
Stop NetworkManager via the appropriate method for your distro:
Fedora
sudo /sbin/service NetworkManager stop
Debian/Ubuntu
sudo /etc/init.d/network-manager stop
or for versions before 0.6.4-8:
sudo /etc/dbus-1/event.d/25NetworkManager stop
Once NetworkManager is stopped start it again from a terminal with:
sudo NetworkManager --no-daemon
Copying the output of NetworkManager and including that in your bug report (remember to remove any wireless encryption keys that might be in the output!) is a great way to help the NetworkManager developers resolve your problem more quickly.