5.6. Connecting to a Network Automatically
For any connection type you add or configure, you can choose whether you want NetworkManager to try to connect to that network automatically when it is available.
Procedure 5.1. Configuring NetworkManager to Connect to a Network Automatically When Detected
Click on the NetworkManager applet icon in the Notification Area.
Click Network Settings at the bottom of the list.
The Network window appears.
Select the type of connection (Wireless) from the left-hand-side menu.
Click the Configure button. The editing a wireless connection window appears.
Configuring the Connection Name, Auto-Connect Behavior, and Availability Settings
Three settings in the
Editing dialog are common to all connection types:
Connection name — Enter a descriptive name for your network connection. This name will be used to list this connection in the Network window as well as in the NetworkManager applet's drop-down menu. By default, wireless connections are named the same as the SSID of the wireless access point. You can rename the wireless connection without affecting its ability to connect, as in the example above, but it is recommended to retain the SSID name.
Available to all users — Check this box to create a connection available to all users on the system. Changing this setting may require root privileges.
Configuring the Wireless Tab
Settings in the wireless tab are explained below:
- SSID
All access points have a Service Set identifier to identify them. However, an access point may be configured not to broadcast its SSID, in which case it is hidden, and will not show up in NetworkManager's list of Available networks. You can still connect to a wireless access point that is hiding its SSID as long as you know its SSID (and authentication secrets).
- Mode
— Set Mode to if you are connecting to a dedicated wireless access point or one built into a network device such as a router or a switch.
— Set
Mode to if you are creating a peer-to-peer network for two or more mobile devices to communicate directly with each other. If you use mode, referred to as
Independent Basic Service Set (
IBSS) in the 802.11 standard, you must ensure that the same
SSID is set for all participating wireless devices, and that they are all communicating over the same channel.
- BSSID
The Basic Service Set Identifier (BSSID) is the MAC address of the specific wireless access point you are connecting to when in Infrastructure mode. This field is blank by default, and you are able to connect to a wireless access point by SSID without having to specify its BSSID. If the BSSID is specified, it will force the system to associate to a specific access point only.
For ad-hoc networks, the BSSID is generated randomly by the mac80211 subsystem when the ad-hoc network is created. It is not displayed by NetworkManager
- MAC address
Like an Ethernet Network Interface Card (NIC), a wireless adapter has a unique MAC address (Media Access Control; also known as a hardware address) that identifies it to the system. Running the ip addr command will show the MAC address associated with each interface. For example, in the following ip addr output, the MAC address for the wlan0 interface (which is 00:1c:bf:02:f8:70) immediately follows the link/ether keyword:
~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 52:54:00:26:9e:f1 brd ff:ff:ff:ff:ff:ff
inet 192.168.122.251/24 brd 192.168.122.255 scope global eth0
inet6 fe80::5054:ff:fe26:9ef1/64 scope link
valid_lft forever preferred_lft forever
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 00:1c:bf:02:f8:70 brd ff:ff:ff:ff:ff:ff
inet 10.200.130.67/24 brd 10.200.130.255 scope global wlan0
inet6 fe80::21c:bfff:fe02:f870/64 scope link
valid_lft forever preferred_lft forever
A single system could have one or more wireless network adapters connected to it. The MAC address field therefore allows you to associate a specific wireless adapter with a specific connection (or connections). As mentioned, you can determine the MAC address using the ip addr command, and then copy and paste that value into the MAC address text-entry field.
- MTU
The MTU (Maximum Transmission Unit) value represents the size in bytes of the largest packet that the connection will use to transmit. If set to a non-zero number, only packets of the specified size or smaller will be transmitted. Larger packets are broken up into multiple Ethernet frames. It is recommended to leave this setting on .
Once you have finished editing the wireless connection, click the Save button and NetworkManager will immediately save your customized configuration. Given a correct configuration, you can successfully connect to your the modified connection by selecting it from the NetworkManager Notification Area applet.
Select Connect automatically to cause NetworkManager to auto-connect to the connection whenever NetworkManager detects that it is available. Unselect the checkbox if you do not want NetworkManager to connect automatically. If the box is unchecked, you will have to select that connection manually in the NetworkManager applet's initial menu to cause it to connect.
