ifup(8) ifup(8)
NAME
ifup - bring a network interface up
ifdown - take a network interface down
SYNOPSIS
ifup IFACE
ifup -h|--help
ifup -V|--version
ifdown IFACE
ifdown -h|--help
ifdown -V|--version
DESCRIPTION
The ifup and ifdown commands may be used to configure
(or, respectively, deconfigure) a network interface based
on interface definitions in the file
/etc/sysconfig/ifconfig.IFACE.
OPTIONS
A summary of options is included below.
-h, --help
Show summary of options.
-V, --version
Show version information.
EXAMPLES
ifup eth0
Bring up the interface defined in the file
/etc/sysconfig/ifconfig.eth0
ONBOOT=no
IFACE=eth0
SERVICE=ipv4-static
IP=192.168.1.22
GATEWAY=192.168.1.1
PREFIX=24
BROADCAST=192.168.1.255
ifdown eth0:2
Bring down the interface defined in the file
/etc/sysconfig/ifconfig.eth0:2
ONBOOT=no
IFACE=eth0
LABEL=eth0:2
SERVICE=dhcpcd
DHCP_START="--waitip"
DHCP_STOP="-k"
# Set PRINTIP="yes" to have the script print the DHCP IP address
PRINTIP="yes"
# Set PRINTALL="yes" to print the DHCP assigned values for
# IP, SM, DG, and 1st NS.
PRINTALL="no"
ifup br0
Bring up the interface defined in the file
/etc/sysconfig/ifconfig.br0
ONBOOT=yes
IFACE=br0
SERVICE="bridge ipv4-static"
IP=192.168.1.22
GATEWAY=192.168.1.1
PREFIX=24
BROADCAST=192.168.1.255
STP=no # Spanning tree protocol, default no
INTERFACE_COMPONENTS=eth0 # Add to IFACE
IP_FORWARD=true
NOTES
The program does not configure network interfaces direct-
ly. It runs scripts defined by the SERVICE variable in
the network configuration file.
The configuration files must have the following environ-
ment variables set:
IFACE - The interface to configure, e.g. eth0. It must
be available in /sys/class/net.
SERVICE - The service script to run to bring up the inter-
face. Standard services are ipv4-static and
ipv4-static-route. Other services such as dhcp
or bridge may be installed. This value may
be a list of services when the interface is a
compound device such as a bridge.
ONBOOT - If set to 'yes', the specified interface is
configured by the netowrk boot script.
GATEWAY - The default IP address to use for routing if
the destination IP address is not in a static
route or on a local network, e.g., 192.168.1.1.
For secondary IP addresses on an interface, this
parameter should not be specified. If the service
is ipv4-static-route, this parameter must NOT
be set.
STATIC_GATEWAY - The default IP address to use for routing
when setting a static routing address.
INTERFACE_COMPONENTS - A list of component interfaces
only needed for a compound device such as a bridge.
This list is normally a single value, e.g. eth0,
for use with a virtual host such as kvm.
Other paramters that are service specific include:
ipv4-static
IP - The IP address of the interface,
e.g. 192.168.1.2.
PREFIX - The number of bits that specify the network
number of the interface. The default, if not
specified, is 24.
LABEL - The label to be assigned to the interface.
This is normally specified for assigning
additional IP addresses to a network
device. Example: eth0:2 (optional)
BROADCAST - The brodcast address for this interface,
e.g 192.168.1.255. If not specified,
the broadcast address will be calculated
from the IP and PREFIX.
ipv4-static-route
TYPE - The type of route, typically 'default',
'network', 'or host'.
IP - The IP address for a network or host, if the
TYPE is not 'default'.
PREFIX - The prefix for the associated IP address.
STATIC_GATEWAY - The IP address for a network route.
SOURCE - The source IP address to prefer when sending
to the destinations covered by the specified
route. (optional)
dhcp/dhclient
DHCP_START - Optional parameters to pass to the dhcp client
at startup.
DHCP_STOP - Optional paremeters to pass to the dhcp client
at shutdown.
PRINTIP - Flag to print the dhcp address to stdout
PRINTALL - Flag to print all obtained dhcp data to stdout
bridge
IP_FORWARD - An optional flag to enable the system to forward
inbound IP packets received by one interface to
another outbound interface.
STP - Set bridge spanning tree protocol. Default is no.
FILES
/etc/sysconfig/ifconfig.*
definitions of network interfaces
AUTHORS
The ifup/ifdown suite was written by Nathan Coulson
<nathan@linuxfromscratch.org> and Kevin P. Fleming
<kpfleming@linuxfromscratch.org>
and updated by Bruce Dubbs <bdubbs@linuxfromscratch>.
SEE ALSO
ip(8).
IFUP/IFDOWN 8 February 2015 ifup(8)