The interface control scripts activate and deactivated system
interfaces. There are two primary interface control scripts,
/sbin/ifdown and /sbin/ifup,
that call on control scripts located in the
/etc/sysconfig/network-scripts/ directory.
The ifup and ifdown interface
scripts are symbolic links to scripts in the /sbin/
directory. When either of these scripts are called, they require the value
of the interface to be specified, such as:
 | Caution |
|---|
| | The ifup and ifdown interface
scripts are the only scripts that the user should use to bring up and
take down network interfaces.
The following scripts are described for reference purposes only. |
Two files used to perform a variety of network initialization tasks
during the process of bringing up a network interface are
/etc/rc.d/init.d/functions and
/etc/sysconfig/network-scripts/network-functions. Refer
to Section 8.4 Network Function Files for more information.
After verifying that an interface has been specified and that the user
executing the request is allowed to control the interface, the correct
script brings the interface up or down. The following are common
interface control scripts found within the
/etc/sysconfig/network-scripts/ directory:
ifup-aliases — Configures IP aliases from
interface configuration files when more than one IP address is
associated with an interface.
ifup-ippp and
ifdown-ippp — Brings ISDN
interfaces up and down.
ifup-ipsec and
ifdown-ipsec — Brings IPsec
interfaces up and down.
ifup-ipv6 and
ifdown-ipv6 — Brings IPv6
interfaces up and down.
ifup-ipx — Brings up an IPX interface.
ifup-plip — Brings up a PLIP interface.
ifup-plusb — Brings up a USB
interface for network connections.
ifup-post and
ifdown-post — Contains commands to be
executed after an interface is brought up or down.
ifup-ppp and
ifdown-ppp — Brings a PPP
interface up or down.
ifup-routes — Adds static routes for
a device as its interface is brought up.
ifdown-sit and ifup-sit
— Contains function calls related to bringing up and down an
IPv6 tunnel within an IPv4 connection.
ifup-sl and ifdown-sl
— Brings a SLIP interface up or down.
ifup-wireless — Brings up a wireless
interface.
 | Warning |
|---|
| | Removing or modifying any scripts in the
/etc/sysconfig/network-scripts/ directory can
cause interface connections to act irregularly or fail. Only advanced
users should modify scripts related to a network interface.
|
The easiest way to manipulate all network scripts simultaneously is to
use the /sbin/service command on the network service
(/etc/rc.d/init.d/network), as illustrated the
following command:
/sbin/service network <action> |
In this example, <action> can be either
start, stop, or
restart.
To view a list of configured devices and currently active network
interfaces, use the following command:
/sbin/service network status |
