Structure of the network scripts in buildroot-ng 1) Usage To be able to access the network functions, you need to include the necessary shell scripts by running: . /etc/functions.sh # common functions include network # include /lib/network/*.sh scan_interfaces # read and parse the network config Some protocols, such as PPP might change the configured interface names at run time (e.g. eth0 => ppp0 for PPPoE). That's why you have to run scan_interfaces instead of reading the values from the config directly. After running scan_interfaces, the 'ifname' option will always contain the effective interface name (which is used for IP traffic) and if the physical device name differs from it, it will be stored in the 'device' option. That means that running 'config_get lan ifname' after scan_interfaces might not return the same result as running it before. After running scan_interfaces, the following functions are available: - find_config looks for a network configuration that includes the specified network interface. - setup_interface [] [] will set up the specified interface, optionally overriding the network configuration name or the protocol that it uses. 2) Writing protocol handlers You can add custom protocol handlers by adding shell scripts to /lib/network. They provide the following two shell functions: scan_() { local config="$1" # change the interface names if necessary } setup_interface_() { local interface="$1" local config="$2" # set up the interface } scan_ is optional and only necessary if your protocol uses a custom device, e.g. a tunnel or a PPP device.