From ArchWiki
Revision as of 20:27, 14 October 2012 by Graysky (talk | contribs) (Net-Auto-Wireless)
Jump to: navigation, search

ro:Netcfg zh-CN:Netcfg Template:Article summary start Template:Article summary text Template:Article summary heading Template:Article summary text Template:Article summary heading Template:Article summary link - Git repo for official package scripts. Template:Article summary wiki - Tips and Tricks for netcfg. Template:Article summary end Netcfg is used to configure and manage network connections via profiles. It has pluggable support for a range of connection types, such as wireless, ethernet, ppp. It is also capable of starting/stopping many to one connections, that is, multiple connections within the same profile, optionally with bonding. Further it is useful for users seeking a simple and robust means of managing multiple network configurations (e.g. laptop users). With the push to drop support for initscripts/sysv, netcfg is one of several choices users have to managing their network connectivity under systemd.

Note: netcfg-2.8.9 drops deprecated rc.conf compatibility. Users of netcfg should configure all interfaces in /etc/conf.d/netcfg rather than /etc/rc.conf.


In the simplest cases, users must at least know the name of their network interface(s) (e.g. eth0, wlan0). If configuring a static IP address, the IP addresses of the default gateway and name server(s) must also be known.

If connecting to a wireless network, have some basic information ready. For a wireless network this includes what type of security is used, the network name (ESSID), and any password or encryption keys. Additionally, ensure the proper drivers and firmware are installed for the wireless device, as described in Wireless Setup.


The netcfg package is available in the official repositories.

As of netcfg version 2.5.x, optional dependencies include wpa_actiond – required for automatic/roaming wireless connections – and ifplugd – required for automatic Ethernet configuration. (More information.)

Users wanting Bash completion support for netcfg, install the bash-completion package from the official repositories.


Network profiles are stored in /etc/network.d. To minimize the potential for errors, copy an example configuration from /etc/network.d/examples/ to /etc/network.d/mynetwork. The file name is the name of the network profile ("mynetwork" is used as an example throughout this article). The name is not a network setting and does not need to match the wireless network name (SSID).

Depending on the connection type and security, use one of the following examples from /etc/network.d/examples as a base.

Wireless Example

Warning: Be wary of examples found on the Internet as they often contain deprecated options that may cause problems!
Connection type/security Example profile
Wireless; WEP hex key wireless-wep
Wireless; WEP string key wireless-wep-string-key
Wireless; WPA-Personal (passphrase/pre-shared key) wireless-wpa
Wireless; WPA-Enterprise wireless-wpa-config (wpa_supplicant configuration is external)
wireless-wpa-configsection (wpa_supplicant configuration stored as string)
Wired; DHCP ethernet-dhcp
Wired; static IP ethernet-static
Wired; iproute configuration ethernet-iproute

Modify the new configuration file, /etc/network.d/mynetwork:

  • Set INTERFACE to the correct wireless or Ethernet interface. This can be checked with ip link and iwconfig.
  • Ensure the ESSID and KEY (passphrase) are set correctly for wireless connections. Typos in these fields are common errors.
    • Note that WEP string keys (not hex keys) must be specified with a leading s: (e.g. KEY="s:somepasskey").
Note: netcfg configurations are valid Bash scripts. Any configuration involving special characters such as $ or \ needs to be quoted correctly otherwise it will be interpreted by Bash. To avoid interpretation, use single quotes or backslash escape characters where appropriate.
Note: Network information (e.g. wireless passkey) will be stored in plain text format, so users may want to change the permissions on the newly created profile (e.g. chmod 0600 /etc/network.d/mynetwork) to make it readable by root only.
Note: For WPA-Personal, it is also possible to use WPA passkey encoded into a hexadecimal string, instead of as a plain text passkey.

Follow the procedure on the WPA supplicant page's first example exercise to generate a hexadecimal string from you WPA passkey.
Save the new hexadecimal string into the wireless WPA profile in /etc/network.d/mynetwork as the value of the KEY variable (make sure this will be the only KEY variable enabled), to look similar to this:


That should do it, without the need to reveal the passkey.

Manual Operation

To connect a profile:

# netcfg mynetwork

To disconnect a profile:

# netcfg down <profile-name>

If successful, users can configure netcfg to connect automatically or during boot. If the connection fails, see #Troubleshooting for solutions and how to get help.

For other functions, see:

$ netcfg help

Automatic Operation

Systemd Support (Recommended)

Since version 2.8.2 netcfg provides systemd unit files.

The service files net-auto-wireless.service and net-auto-wired.service correspond to the initscripts daemons /etc/rc.d/net-auto-wireless and /etc/rc.d/net-auto-wired. To connect to multiple profiles at boot, use netcfg.service which is equivalent to /etc/rc.d/net-profiles and starts all profiles specified in the NETWORKS array in /etc/conf.d/netcfg. These service files can be enabled and started with systemctl as usual.

Named templates

Use the template service file netcfg@xxx.service that allows connection to a profile on boot without having to specify it in /etc/conf.d/netcfg. To specify the desired profile, enable the template service and use the network profile name as the instance name.


# systemctl enable netcfg@<profile-name>.service


This allows users to automatically connect to wireless networks with proper roaming support. To use this, the wpa_actiond package is required. Note that wireless-wpa-config profiles do not work with net-auto-wireless. Convert them to wireless-wpa-configsection instead.

Specify the desired wireless interface with the WIRELESS_INTERFACE variable in /etc/conf.d/netcfg or define a list of wireless networks that should be automatically connected with the AUTO_PROFILES variable in /etc/conf.d/netcfg. Enable the net-auto-wireless.service so systemd manages it.

Note: If AUTO_PROFILES is not set, all wireless networks will be tried.


# systemctl enable net-auto-wireless.service


SysV Support (Soon to be Depreciated/Legacy)


net-profiles allows users to connect profiles during boot.

To enable this feature, users must add net-profiles to the DAEMONS array in /etc/rc.conf and specify profiles to try in the NETWORKS array in /etc/conf.d/netcfg:

DAEMONS=(... net-profiles ...)
NETWORKS=(mynetwork yournetwork)

A network profile can also be started in the background by prefixing it with a @ in the NETWORKS array. Note that one should only do this if the backgrounded profiles configure separate interfaces, otherwise race conditions may occur.

NETWORKS=(@mynetwork @yournetwork)

Alternatively, net-profiles can be configured to restore the profiles that were active at last shutdown by setting the NETWORKS array to last, as described below.


Finally, net-profiles can be configured to display a menu – allowing users to choose a desired profile – by setting the contents of the NETWORKS array to menu:


Additionally, the dialog package is required.

Tip: Access the menu at any time by running netcfg-menu in a terminal.


To enable this feature, users must add net-auto-wireless to the DAEMONS array in /etc/rc.conf:

DAEMONS=(... net-auto-wireless ...)

And specify the desired wireless interface with the WIRELESS_INTERFACE variable in /etc/conf.d/netcfg:


It is also possible to define a list of wireless networks that should be automatically connected with the AUTO_PROFILES variable in /etc/conf.d/netcfg. If AUTO_PROFILES is not set, all wireless networks will be tried.

Additionally, the wpa_actiond package is required. Note that wireless-wpa-config profiles do not work with net-auto-wireless. Convert them to wireless-wpa-configsection instead.


net-auto-wired allows users to automatically connect to wired networks.

To enable this feature, users must install ifplugd, then add net-auto-wired to the DAEMONS array in /etc/rc.conf and specify the desired wired interface with the WIRED_INTERFACE variable in /etc/conf.d/netcfg:

DAEMONS=(... net-auto-wired ...)

The daemon starts an ifplugd process which runs /etc/ifplugd/netcfg.action when the status of the wired interface changes (e.g. a cable is plugged in or unplugged). On plugging in a cable, attempts are made to start any profiles with CONNECTION = "ethernet" or "ethernet-iproute" and INTERFACE = WIRED_INTERFACE until one of them succeeds.

Note: DHCP profiles are tried before static ones, which could lead to undesired results in some cases. However, one can tell netcfg to prefer a particular interface by adding AUTO_WIRED=1 to the desired profile.
Note: The net-auto-wired daemon cannot start multiple ifplugd processes for multiple interfaces (unlike ifplugd's own /etc/rc.d/ifplugd which can).



To run netcfg with debugging output, set the NETCFG_DEBUG environment variable to "yes", for example:

# NETCFG_DEBUG="yes" netcfg <arguments>

Debugging information for wpa_supplicant can be logged using WPA_OPTS within a profile, for example:


Whatever is entered here will be added to the command when wpa_supplicant is called.

Network unavailable

This error is typically due to:

  • Out of range; or
  • Driver issue.

Wireless association failed

This error is typically due to:

  • Out of range/reception;
  • Incorrect configuration;
  • Invalid key;
  • Driver problem; or
  • Trying to connect to a hidden network.

If the connection problem is due to poor reception, increase the TIMEOUT variable in /etc/network.d/mynetwork, such as:


If an AP with a hidden SSID is used, try:

PRE_UP='iwconfig $INTERFACE essid $ESSID'

Unable to get IP address with DHCP

This error is typically due to:

  • Out of range/reception

Try increasing DHCP_TIMEOUT variable in your network /etc/network.d/profile.

Not a valid connection, check spelling or look at examples

You must set CONNECTION to one of the connection types listed in the /usr/lib/network/connections directory. Alternatively, use one of the provided configuration examples in /etc/network.d/examples.

No Connection

Carrier Timeout

If you get a set of debug messages similar to the following (remembering that profile names and interface names may be different), it could be that the process of bringing up the interface is taking too long.

 DEBUG: Loading profile eth0-dhcp
 DEBUG: Configuring interface eth0
 :: eth0-dhcp up
 DEBUG: status reported to profile_up as:
 DEBUG: Loading profile eth0-dhcp
 DEBUG: Configuring interface eth0
 DEBUG: ethernet_iproute_up ifup
   > No connection
 DEBUG: profile_up connect failed

The default is 2 seconds. To lengthen the timeout, set the CARRIER_TIMEOUT variable before calling netcfg.

This thread shows one example of this issue:

Skip no carrier

When you can manually bring up an interface but the journal says „No connection“ during boot, it might be that the physical connection cannot be detected fast enough. Try adding


to your profile. Netcfg will then assign the IP address regardless of whether there is a cable actually attached.

Driver quirks

Note: You most likely do not need quirks; ensure your configuration is correct before considering them. Quirks are intended for a small range of drivers with unusual issues, many of them older versions. These are workarounds, not solutions.

Some drivers behave oddly and need workarounds to connect. Quirks must be enabled manually. They are best determined by reading the forums, seeing what others have used, and, if that fails, trial and error. Quirks can be combined.

Run iwlist $INTERFACE scan before attempting to connect (Broadcom)
Run iwconfig $INTERFACE essid $ESSID before attempting to connect (ipw3945, Broadcom and Intel PRO/Wireless 4965AGN)
Same as previous, run before starting wpa_supplicant. Not supported anymore - use IWCONFIG="essid $ESSID" instead. (ath9k)
Take interface down before association and then restore it after (madwifi)
Sleep one second before checking if the association was successful
Run iwlist scan after associating

Add the required quirks to the netcfg configuration file /etc/network.d/mynetwork, for example:

QUIRKS=(prescan preessid)

If you receive "Wireless network not found", "Association failed" errors and have tried the above, or if an AP with a hidden SSID is used, see the above section #Wireless association failed.

Ralink legacy drivers rt2500, rt2400 that use iwpriv

There is no plans to add WPA support to these drivers. rt2x00 is supported, however, and will replace these.

If you must use them, create a shell script that runs the needed iwpriv commands and put its path in PRE_UP.

find: "/var/run/network//suspend/": No such file or directory

If you get this error message, then do not bother because it is a known bug. Create the directory by hand.

It still does not work, what do I do?

If this article did not help solve your problem, the next best places to ask for help are the forums, the mailing list, and the #archlinux IRC channel.

To be able to determine the problem, we need information. When you ask, provide the following output:

  • ALL OUTPUT FROM netcfg
    • This is absolutely crucial to be able determine what went wrong. The message might be short or non-existent, but it can mean a great deal.
  • /etc/network.d network profiles
    • This is also crucial as many problems are simple configuration issues. Feel free to censor your wireless key.
  • netcfg version
  • lsmod
  • iwconfig