Interface Control Scripts - Red Hat ENTERPRISE LINUX 3 Reference Manual

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• WVDIALSECT= name
/etc/wvdial.conf
mation for the interface.
8.2.6. Other Interfaces
Other common interface configuration files that use these options include the following:
— A local loopback interface is often used in testing, as well as being used in a variety
• ifcfg-lo
of applications that require an IP address pointing back to the same system. Any data sent to the
loopback device is immediately returned to the host's network layer.
Warning
Never edit the loopback interface script,
ally. Doing so can prevent the system from operating correctly.
— An infrared interface allows information between devices, such as a laptop and
•
ifcfg-irlan0
a printer, to flow over an infrared link. This works in a similar way to an Ethernet device except that
it commonly occurs over a peer-to-peer connection.
— A Parallel Line Interface Protocol (PLIP) connection works much the same way
• ifcfg-plip0
as an Ethernet device, except that it utilizes a parallel port.
— Token Ring topologies are not as common on Local Area Networks (LANs) as they
• ifcfg-tr0
once were, having been eclipsed by Ethernet.

8.3. Interface Control Scripts

The interface control scripts activate and deactivated system interfaces. There are two primary in-
terface control scripts,
/etc/sysconfig/network-scripts/
The and
ifup ifdown
either of these scripts are called, they require the value of the interface to be specified, such as:
ifup eth0
Caution
The and
ifup ifdown
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
/etc/sysconfig/network-scripts/network-functions
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
, where
name
. This file contains the phone number to be dialed and other important infor-
and
/sbin/ifdown
directory.
interface scripts are symbolic links to scripts in the
interface scripts are the only scripts that the user should use to bring up and
a network interface
/etc/sysconfig/network-scripts/
associates this interface with a dialer configuration in
/etc/sysconfig/network-scripts/ifcfg-lo
, that call on control scripts located in the
/sbin/ifup
are
/etc/rc.d/init.d/functions
. Refer to Section 8.4 Network
Chapter 8. Network Interfaces
directory. When
/sbin/
directory:
, manu-
and