Configuring Static IP Addresses¶
It is sometimes desirable to provide static IP configuration for network interface instead of relying on DHCP. Below we describe several methods of doing that.
Using ConnMan¶
ConnMan is the default Yocto network manager. Network manager is a program for providing detection and configuration for systems to automatically connect to network. In the examples below we demonstrate how ConnMan command line tool, connmanctl, can be used create static IP configuration.
Configuring wired interfaces¶
To get the list of wired interfaces run
For example:
Wired interfaces will be shown as ethernet_
To create static IP configuration run
# connmanctl config <service> --ipv4 manual <ip address> <netmask> <gateway>
# connmanctl config <service> --nameservers <dns-addr>
For example:
# connmanctl config ethernet_0eb31468dcc9_cable --ipv4 manual 192.168.1.100 255.255.255.0 192.168.1.254
# connmanctl config ethernet_0eb31468dcc9_cable --nameservers 8.8.8.8 4.4.4.4
The configuration will be saved in /var/lib/connman/ethernet_0eb31468dcc9_cable/settings.
Configuring wireless interfaces¶
To check if wifi is enabled run
and check for the line that says Powered: True/False.
To power the wifi on run
To scan the network connmanctl accepts simple names called technologies. To scan for nearby wifi networks:
To list the available networks found after a scan run (example output):
MyNetwork wifi_dc85de828967_68756773616d_managed_psk
OtherNET wifi_dc85de828967_38303944616e69656c73_managed_psk
AnotherOne wifi_dc85de828967_3257495245363836_managed_wep
FourthNetwork wifi_dc85de828967_4d7572706879_managed_wep
AnOpenNetwork wifi_dc85de828967_4d6568657272696e_managed_none
Every wifi network is identified by a name composed as
Connecting to an open network¶
To connect to an open network, look for wifi networks ending with _managed_none:
Network names can be tab-completed
You should now be connected to the network. Check using ip addr or run
Connecting to a protected network¶
Start connmanctl in interactive mode by running
Now you need to register the agent to handle user requests. The command is:
You now need to connect to one of the protected services.
To do this easily, just use tab completion for the wifi_ service.
If you were connecting to OtherNET in the example above you would type:
The agent will then ask you to provide any information the daemon needs to complete the connection.
The information requested will vary depending on the type of network you are connecting to.
The agent will also print additional data about the information it needs as shown in the example below.
Agent RequestInput wifi_dc85de828967_38303944616e69656c73_managed_psk
Passphrase = [ Type=psk, Requirement=mandatory ]
Passphrase?
Provide the information requested, in this example the passphrase, and then type:
If the information you provided is correct you should now be connected to the protected access point.
Configuring Static IP¶
To create static IP configuration run
# connmanctl config <service> --ipv4 manual <ip address> <netmask> <gateway>
# connmanctl config <service> --nameservers <dns-addr>
For example:
# connmanctl config wifi_dc85de828967_38303944616e69656c73_managed_psk --ipv4 manual 192.168.1.100 255.255.255.0 192.168.1.254
# connmanctl config wifi_dc85de828967_38303944616e69656c73_managed_psk --nameservers 8.8.8.8 4.4.4.4
The configuration will be saved in /var/lib/connman/wifi_dc85de828967_38303944616e69656c73_managed_psk/settings.
Using NetworkManager¶
NetworkManager is an alternative network manager that can be used instead of ConnMann. Both network managers cannot coexist in the same Yocto image, so enabling NetworkManager requires disabling ConnMan and rebuilding the image.
In the examples below we use NetworkManager command line tool, nmcli, to create static configurations.
Configuring wired interfaces¶
To create static IP configuration run
# nmcli con add type ethernet ifname <ethX> con-name <name> ip4 <ipaddr> gw4 <gwaddr>
# nmcli con mod static-eth0 ipv4.dns "<dns1>,<dns2>"
# nmcli con up <name>
For example, to create configuration for eth0 run
# nmcli con add type ethernet ifname eth0 con-name static-eth0 ip4 192.168.1.100/24 gw4 192.168.1.254
# nmcli con mod static-eth0 ipv4.dns "8.8.8.8,4.4.4.4"
# nmcli con up static-eth0
The configuration will be saved in /etc/NetworkManager/system-connections/static-eth0.
Configuring wireless interfaces¶
To check if WIFI is enabled by NetworkManager run
and check the GENERAL.STATE line. If WIFI is enabled, the state is either connected or disconnected. If WIFI is disabled the state is unavailable.
To enable WIFI run
or if you need to disable it you can run
If WIFI is enabled you can get the list of available APs by running
SSID MODE CHAN RATE SIGNAL BARS SECURITY
MyNetwork Infra 149 54 Mbit/s 100 **** WPA1 WPA2
OtherNetwork Infra 11 54 Mbit/s 75 *** WPA2
AnotherNetwork Infra 6 54 Mbit/s 75 *** WPA2
FourthNetwork Infra 64 54 Mbit/s 60 *** WPA2
OpenNetwork Infra 3 54 Mbit/s 37 ** --
To connect to an open WIFI network run
To connect to a protected WIFI network run
To check connection status run
Configuring static IP¶
By default WIFI connection will use DHCP. To switch to static IP configuration run the following commands:
# nmcli con mod <SSID> ipv4.method manual ipv4.addr <ipaddr>/<netmask> ipv4.gateway <gwaddr> ipv4.dns "<dns1>,<dns2>"
# nmcli con down <SSID>
# nmcli con up <SSID>
For example
# nmcli con mod MyNetwork ipv4.method manual ipv4.addr "192.168.1.100/24" ipv4.gateway 192.168.1.254 ipv4.dns "8.8.8.8,4.4.4.4"
# nmcli con down MyNetwork
# nmcli con up MyNetwork
The configuration will be saved in /etc/NetworkManager/system-connections/
Using /etc/network/interfaces¶
This is a legacy method with various limitations and we do not recommend using it, especially in combination with network managers. The configuration file /etc/network/interfaces is used by ifup and ifdown tools to perform network interface configuration. In the SystemV init setup ifup and ifdown are invoked by /etc/init.d/networking boot script. In systemd setup /etc/init.d/networking is not available and you should create your own systemd service file that invokes "ifup -a" on startup and "ifdown -a" at shutdown.
If you configure all network interfaces via /etc/network/interfaces, it is better to completely disable the network manager service.
The example below configures eth0
auto eth0
iface eth0 inet static
address 192.168.1.100
netmask 255.255.255.0
gateway 192.168.1.254
dns-nameservers 8.8.8.8 4.4.4.4
dns-search foo.org bar.com
The DNS settings in /etc/network/interfaces rely on the availability of /sbin/resolvconf tool to update /etc/resolv.conf configuration file. If /sbin/resolvconf is not present, rebuild Yocto image after adding the following line to conf/local.conf
# Yocto Hardknott and older
IMAGE_INSTALL_append = " resolvconf"
# Yocto Kirkstone and newer
IMAGE_INSTALL:append = " resolvconf"
Configuring WIFI via /etc/network/interfaces is not recommended.
Interaction with ConnMan¶
ConnMan will override the settings in /etc/network/interfaces unless configured to ignore relevant interfaces. For example, after configuring eth0 and eth1 in /etc/network/interfaces, you should create /etc/connman/main.conf and add the following:
ConnMan will also override the contents of /etc/resolv.conf as it includes its own DNS proxy. To prevent that, start ConnMan with the options "-r" or "--nodnsproxy"
Interaction with NetworkManager¶
NetworkManager may override the contents of /etc/resolv.conf. To prevent that, create /etc/NetworkManager/NetworkManager.conf and add the following:
Using systemd-networkd¶
systemd-networkd is a system daemon that manages network configurations. It detects and configures network devices as they appear. systemd-networkd is an alternative network manager that can be used instead of ConnMann or NetworkManager. The network managers cannot coexist in the same Yocto image, so enabling systemd-networkd requires disabling NetworkManager and ConnMan and rebuilding the image.
Create /etc/systemd/network/00-static.network with the following content:
Restart systemd-networkd