netctl
zh-CN:Netctl Template:Article summary start Template:Article summary text Template:Article summary heading Template:Article summary text Template:Article summary heading Template:Article summary wiki Template:Article summary end
Netctl is a CLI-based tool used to configure and manage network connections via profiles. It is a native Arch Linux project that replaces the old netcfg utility.
Contents
Installation
The netctl package is available in the official repositories. Installing netctl will replace netcfg.
netctl and netcfg are conflicting packages. You will be potentially connectionless after installing netctl if your profiles are misconfigured.
systemctl --type=service
to ensure that no other service is running that may want to configure the network. Multiple networking services will conflict.Required reading
It is advisable to read the following man pages before using netctl:
Configuration
netctl
may be used to introspect and control the state of the systemd services for the network profile manager. Example configuration files are provided for the user to assist them in configuring their network connection. These example profiles are located in /etc/netctl/examples/
. The common configurations include:
- ethernet-dhcp
- ethernet-static
- wireless-wpa
- wireless-wpa-static
For wireless settings, use wifi-menu -o will generate the config file in /etc/netctl.
To use an example profile, simply copy one of them from /etc/netctl/examples/
to /etc/netctl/
and configure it to your needs:
# cp /etc/netctl/examples/wireless-wpa /etc/netctl/profile
Once you have created your profile, make an attempt to establish a connection using the newly created profile by running:
# netctl start profile
If issuing the above command results in a failure, then use journalctl -xn
and netctl status profile
in order to obtain a more in depth explanation of the failure. Make the needed corrections to the failed configuration and retest.
Automatic operation
If you use only one profile (per interface) or don't have to switch profiles too frequently, the basic method will do. Most common examples are servers, workstations, routers etc.
If you need to switch multiple profiles frequently, use Automatic switching of profiles. Most common examples are laptops.
Basic method
With this method, you can statically start only one profile per interface. First manually check that the profile can be started successfully, then it can be enabled
using
# netctl enable profile
This will create and enable a systemd service that will start when the computer boots.
SkipNoCarrier=yes
in your profile.Automatic switching of profiles
netctl
provides two special services for automatic switching of profiles: netctl-auto@interface.service
for wireless interfaces, and netctl-ifplugd@interface.service
for wired interfaces. Using netctl-auto@interface.service
, netctl profiles change as you move from range of one network into range of other network. Using netctl-ifplugd@interface.service
, netctl profiles change as you plug the cable in and out.
netcfg
used net-auto-wireless.service
and net-auto-wired.service
for this purpose.First install required packages:
- Package wpa_actiond is required to use
netctl-auto@interface.service
. - Package ifplugd is required to use
netctl-ifplugd@interface.service
.
Now configure all profiles that netctl-auto@interface.service
or netctl-ifplugd@interface.service
can start. If you want some profile not to be started automatically by these services, you have to explicitly add ExcludeAuto=yes
to that profile. You can use Priority=
to set priority of some profile when multiple profiles are available. See netctl.profile(5)
for details.
Security=wpa-config
, please use Security=wpa-configsection
instead.Once your profiles are set and verified to be working, simply enable these services with
# systemctl enable netctl-auto@interface.service # systemctl enable netctl-ifplugd@interface.service
Key=
variable, the unit will fail to load at boot.netctl
, run # netctl disable profileto prevent the profile from starting twice at boot.
- If there is ever a need to alter a currently enabled profile, execute
netctl reenable <profile>
to apply the changes. - interface is hardware minus, e.g netctl-auto@wlan0.service or netctl-auto@enp2s0.service
Migrating from netcfg
netctl
uses /etc/netctl
to store its profiles, not /etc/network.d
(netcfg
's profile storage location).
In order to migrate from netcfg, at least the following is needed:
- Disable the netcfg service:
systemctl disable netcfg.service
. - Uninstall netcfg and install netctl.
- Move network profile files to the new directory.
- Rename variables therein according to
netctl.profile(5)
(Most variable names have onlyUpperCamelCase
i.eCONNECTION
becomesConnection
). - For static IP configuration make sure the
Address
variables have a netmask after the IP (e.g.Address=('192.168.1.23/24' '192.168.1.87/24')
in the example profile). - If you setup a wireless profile according in the
wireless-wpa-configsection
example, note that this overrideswpa_supplicant
options defined above the brackets. For a connection to a hidden wireless network, addscan_ssid=1
to the options in thewireless-wpa-configsection
;Hidden=yes
does not work there. - Unquote interface variables and other variables that don't strictly need quoting (this is mainly a style thing).
- Run
netctl enable profile
for every profile in the oldNETWORKS
array. last doesn't work this way, seenetctl.special(7)
. - Use
netctl list
and/ornetctl start profile
instead of netcfg-menu. wifi-menu remains available. - Unlike
netcfg
, by defaultnetctl
fails to bring up a NIC when it is not connected to another powered up NIC. To solve this problem, addSkipNoCarrier=yes
at the end of your/etc/netctl/profile-file
.
Passphrase obfuscation (256-bit PSK)
Users not wishing to have the passphrase to their wireless network stored in plain text have the option of storing the corresponding 256-bit pre-shared key (PSK) instead, which is calculated from the passphrase and the SSID using standard algorithms.
- Method 1: Use
wifi-menu -o
to generate a config file in/etc/netctl
- Method 2: Manual settings as follows. If the passphrase fails, try removing the \" in Key= (see note below)
For both methods it is suggested to chmod 600 /etc/netctl/<config_file>
to prevent user access to the password.
Calculate your 256-bit PSK using wpa_passphrase:
Usage: wpa_passphrase [ssid] [passphrase]
$ wpa_passphrase archlinux freenode
In a second terminal window, copy the example file wireless-wpa
from /etc/netctl/examples
to /etc/netctl
:
# cp /etc/netctl/examples/wireless-wpa /etc/netctl/wireless-wpa
You will then need to edit /etc/netctl/wireless-wpa
using your favorite text editor and add the pre-shared key, that was generated earlier using wpa_passphrase, to the Key
variable of this profile.
Once completed your network profile wireless-wpa
containing a 256-bit PSK should resemble:
/etc/netctl/wireless-wpa
Description='A simple WPA encrypted wireless connection using 256-bit PSK' Interface=wlp2s2 Connection=wireless Security=wpa IP=dhcp ESSID=archlinux Key=\"64cf3ced850ecef39197bb7b7b301fc39437a6aa6c6a599d0534b16af578e04a
- Make sure to use the special non-quoted rules for
Key=
that are explained at the end of netctl.profile(5). - The key that you put in the profile configuration is enough to connect to a WPA-PSK network, which means this procedure is only good to hide the human-readable passphrase but will not prevent anyone with read access to this file from connecting to the network. You should ask yourself if there is any use in this at all, since using the same passphrase for anything else is a very poor security measure.
Support
Official announcement thread: https://bbs.archlinux.org/viewtopic.php?id=157670
Tips and tricks
Replace 'netcfg current'
As of April 2013 there is no netctl alternative to netcfg current
. If you relied on it for something, like a status bar for a tiling window manager, you can now use:
# netctl list | awk '/*/ {print $2}'
or, when netctl-auto
was used to connect:
# wpa_cli -i interface status | sed -n 's/^id_str=//p'
Eduroam
Some universities use a system called "Eduroam" to manage their wireless networks. For this system, a WPA config-section profile with the following format is often useful:
/etc/netctl/wlan0-eduroam
Description='Eduroam-profile for <user>' Interface=wlan0 Connection=wireless Security=wpa-configsection IP=dhcp WPAConfigSection=( 'ssid="eduroam"' 'proto=RSN' 'key_mgmt=WPA-EAP' 'pairwise=CCMP' 'auth_alg=OPEN' 'eap=PEAP' 'identity="<user>"' 'password="<password>"' )