ifcfg(5) Networking ifcfg(5)NAMEifcfg - Configuration file for network interfaces
DESCRIPTION
The ifup and ifdown scripts use configuration files of the format
ifcfg-[InterfaceName], for example ifcfg-eth0. These configuration
files are searched for in the following places:
/etc/sysconfig/network-scripts
FORMAT
The file is a series of variable settings in the form:
NAME="value"
It is allowable to surround value with double quotes or single quotes.
It is required if the settings require spaces (no settings in the net‐
work configuration use spaces).
PARAMETERS
The following are required settings:
DEVICE The network device name.
BOOTPROTO
The protocol or system used to obtain an IP. Valid settings are
bootp, dhcp,
ONBOOT Determines whether the device is started at system bootup.
Valid settings are yes or no.
The following are required settings for static IP:
IPADDR Manually set the IP address.
NETMASK
The mask that is applied to packets to determine if it's des‐
tined for your network. It is a series of bits that provide a
"mask" for a logical AND with the addresses in the packets it
receives.
The following are optional settings:
NETWORK
Set the network address. This setting is optional because the
network scripts can calculate it as long as the IP address and
Netmask are known (uses a logical AND with the netmask.) Exam‐
ple: a 24 bit netmask is 255.255.255.0. If the IP address is
192.168.1.20, the network is 192.168.1.0.
BROADCAST
Set the broadcast address. This setting is optional because the
network scripts can calculate it as long as the IP address and
Netmask are known (uses a logic OR using the inverse of the net‐
mask with the network address.) Example: a 24 bit netmask is
255.255.255.0, so the inverse is 0.0.0.255. If the IP address
is 192.168.1.20, the broadcast is 192.168.1.255.
MACADDR
Manually set the MAC Address (hardware address) of the inter‐
face. Note that not all network drivers allow this.
DHCP_HOSTNAME
Manually set a hostname that is required for DHCP to obtain the
IP address successfully. Frequently used for cablemodems.
NEEDHOSTNAME
Controls whether or not the hostname is changed to what is sup‐
plied by the DHCP server. Valid settings are yes or no, default
is no.
PEERDNS
Controls whether or not /etc/resolv.conf is rewritten with the
information from a DHCP server. Valid settings are yes or no,
default is yes.
PEERYP Controls whether or not /etc/yp.conf is rewritten with the
information from a DHCP server. Valid settings are yes or no,
default is no.
PEERNTPD
Controls whether or not /etc/ntpd.conf is rewritten with the
information from a DHCP server. Valid settings are yes or no,
default is no.
DHCP_TIMEOUT
Sets the number of seconds to wait for an answer from a DHCP
server, default is 60 seconds.
MTU Sets the Maximum Transmission Unit, default is 1500.
DYNCONFIG
NOZEROCONF
Controls whether or not the zeroconf networking configuration
will be used. Valid settings are yes or no, default is yes.
ISALIAS
Determines if an IP address configuration is an alias or a real
interface. Valid settings are yes or no, default is no.
NETWORKING_IPV6
Determines if an interface is an IPv6 interface. Valid settings
are yes or no, default is no.
IPX Determines if an interface is an IPX interface. Valid settings
are yes or no, default is no.
The following are options specifically for wireless interfaces. The
options are not checked. They passed directly to the iwconfig utility.
Refer to the manual page for iwconfig to see exactly what they do.
WIRELESS_MODE
Sets the mode of the wireless device.
WIRELESS_ESSID
Sets the ESSID of the wireless device.
WIRELESS_NWID
Sets the NWID of the wireless device.
WIRELESS_FREQ
Sets the frequency that the wireless device will use.
WIRELESS_CHANNEL
Sets the channel at the wireless device will use.
WIRELESS_SENS
Sets the sensitivity of the wireless device.
WIRELESS_RATE
Sets the bit rate of the wireless device.
WIRELESS_ENC_KEY
Sets the encryption mode to use.
WIRELESS_RTS
Sets the rts threshhold.
WIRELESS_FRAG
Sets the maximum fragment size.
WIRELESS_IWCONFIG
Options that you can specify to be passed to iwconfig directly.
If it contains one or more spaces, the value must be in quotes.
WIRELESS_IWSPY
Options that you can specify to be passed to iwspy directly. If
it contains one or more spaces, the value must be in quotes.
WIRELESS_IWPRIV
Options that you can specify to be passed to iwpriv directly.
If it contains one or more spaces, the value must be in quotes.
EXAMPLES
ifcfg-eth0 configured for DHCP:
DEVICE=eth0
BOOTPROTO=dhcp
NETMASK=255.255.255.0
ONBOOT=yes
ifcfg-usb0 configurd for static IP:
DEVICE=usb0
BOOTPROTO=static
BROADCAST=192.168.129.255
IPADDR=192.168.129.1
NETMASK=255.255.255.0
NETWORK=192.168.129.0
ONBOOT=no
ifcfg-eth0:2 (the third virtual device) configured for static IP:
DEVICE="eth0:2"
IPADDR=192.168.3.89
NETMASK=255.255.255.0
ONBOOT=yes
FILES
/etc/sysconfig/network-scripts/ifcfg-*
/etc/sysconfig/network
/etc/resolv.conf
/sbin/ifup
/sbin/ifdown
SEE ALSOifup(8)ifdown(8)Todd Lyons <;tlyons@mandrakesoft.com> 1.0.0 ifcfg(5)
