Triggering network settings

We already know how to set and reset interfaces for triggering network settings. These actions must be completed as appropriate. Traditionally, the network is set by the/etc/rcS. d/S40networking script at startup, and rarely reset. Other services that require the network are subsequently started. During shutdown or restart, initscripts is executed in reverse order. However, GNU and Linux are now moving towards support for dynamic hardware replacement and emergencies. The first is to provide support for replaceable PCMCIA cards. After the hotplug mechanism is added, many peripherals can be replaced when the computer is running. This also includes network hardware. Note! When you unplug a hardware device, services related to this hardware need to be disabled after the device is started or deleted. This means that such services need to be deleted from the System V init System and are under ifupdown control. For example, assume that the Service foo controlled by initscript/etc/init. d/foo depends on the dynamically set network interface eth0. First, delete foo from the init system. If you are using the sysv-rc init system, complete the following items. # Rm/etc/rc [2345]. d/S ?? Foo then puts foo under the control of ifupdown by adding the up and down options in the eth0 section of/etc/network/interfaces. This file can also call the foo initialization script (initscript): iface eth0 inet dhcpup/etc/init. d/foo startdown/etc/init. d/foo stop