You can configure network interfaces either during system setup or when the storage system is operating. When the storage system is operating, you can use the ifconfig command to assign or modify configuration values of your network interfaces.
During system setup, you can configure the IP addresses for the network interfaces. An ifconfig command is included in the /etc/rc file of the root volume for each network interface that you configured during the system setup. After your storage system has been set up, the ifconfig commands in the /etc/rc file are used to configure the network interfaces on subsequent storage system reboots.
You can use the ifconfig command to change values of parameters for a network interface when your storage system is operating. However, such changes are not automatically included in the /etc/rc file. If you want your configuration modifications to be persistent after a reboot, you must include the ifconfig command values in the /etc/rc file.