Tuesday, February 3, 2009

Ubuntu Network Manager

Ubuntu uses NetworkManager to detect both wired and wireless network connections. NetworkManager uses the automatic device detection capabilities of udev and the Hardware Abstraction Layer (HAL) to configure your connections. NetworkManager is turned on by default. With multiple wireless access points for Internet connections, a system could have several different network connections from which to choose, instead of a singleline connection such as DSL or cable. This is particularly true for notebook computers that could access different wireless connections at different locations. Instead of manually configuring a new connection each time one is encountered, the NetworkManager tool can automatically configure and select a connection to use.

By default, an Ethernet connection is preferred if available, because direct lines that support Ethernet connections are normally considered faster than wireless connections. For wireless connections, you will need to choose the one you want.

NetworkManager is designed to work in the background, providing status information for your connection and switching from one configured connection to another as needed. For initial configuration, it detects as much information as possible about the new connection. It operates as a GNOME desktop panel applet, monitoring your connection, and it can work on any Linux distribution.

NetworkManager operates as a daemon. If no Ethernet connection is available, NetworkManager will scan for wireless connections, checking for extended service set identifiers (ESSIDs). If an ESSID identifies a previously used connection, it is automatically selected. If several are found, the most recently used connection is chosen. If only a new connection is available, NetworkManager waits for the user to choose one. A connection is selected only if the user is logged in. If an Ethernet connection is made later, NetworkManager will switch to it from wireless.

NetworkManager is user-specific. When a user logs in, it selects the network preferred by that user. The first time a user runs NetworkManager, the notification applet will display a list of current connections from which the user can choose.

Network interface connection (NIC) hardware is detected using HAL. Information provided by NetworkManager is made available to other applications over D-Bus, the message bus system. Features currently under development include virtual private network (VPN) and application notification. NetworkManager uses the dhcpcd client to gather network information. For user interaction and notification, it uses NetworkManagerInfo.

NetworkManager on GNOME
NetworkManager displays a network icon on the right side of the GNOME desktop’s top panel. Click the icon to see a list of all available network connections, including available wireless connections available:

A lock icon appears next to password-protected access points. You can configure hidden access points yourself. Choose Other Wireless Networks from the list to open a dialog where you can enter the ESSID of the network, the key type, and the password. Included is the option to perform a manual configuration, which will invoke network-admin, described in the next section. Right-click to access the option for shutting off your connection (Work Offline) or to see information about the connection:

NetworkManager for KDE: KNetworkManager
The KDE interface version of NetworkManager, KNetworkManager, also displays network connections. Click its icon on the panel to display available connections:

To see information about the current connection, right-click the icon. A window displays with tabs for Device, Addresses, Statistics, and Network. KNetworkManager also performs manual configurations such as PPP dial-up configuration and manages wireless connections. To start kdenetworkmanager for manual configuration, right-click on its icon in the panel and select Manual Configuration.

Wireless Manual Configuration and Editing
You use the Network Manager Editor to edit and configure your wireless connections manually. Right-click the NetworkManager applet and choose Edit Wireless Connections to open the Wireless Networks window, where you’ll see all your wireless connections. You can then select those you want to edit and change a name, bssids, and encryption (Security). You can access this tool directly by choosing Applications | Internet | Network Manager Editor.

Source of Information : McGraw Hill Ubuntu The Complete Reference

No comments: