/etc/network/interfaces - network interface configuration for ifup and
ifdown
/etc/network/interfaces contains network interface configuration information
for the ifup(8) and ifdown(8) commands. This is where you configure
how your system is connected to the network, by setting IP
addresses, and other related information.
The file can contain comments; all lines starting with `#' are ignored.
A line may be extended across multiple lines by making the last character
a \ in the usual manner.
The file consists of zero or more "iface", "mapping" and "auto" stanzas,
each of which defines one network interface. Here are some sample
stanzas:
auto lo eth0
iface lo inet loopback
mapping eth0
script /usr/local/sbin/map-scheme
map HOME eth0-home
map WORK eth0-work
iface eth0-home inet static
address 192.168.1.1
netmask 255.255.255.0
iface eth0-work inet dhcp
Stanzas beginning with the word "auto" are used to identify interfaces
that should be brought up automatically on system boot. Interface names
should follow the word "auto" on the same line. Multiple "auto" stanzas
may be used, or they may be combined into a single line.
Stanzas beginning with the word "mapping" are used to automatically
translate a physical interface name into a logical interface specified
by an "iface" stanza. The first line of a mapping stanza begins with
the word "mapping" followed by the names of each physical interface
this mapping should apply to. Shell globs (* and ? wildcards) may be
used when specifying interfaces. Each mapping must specify a script,
which will be run when the mapping is applied. In addition, a mapping
may specify any number of "map" parameters that will be passed to the
script.
Stanzas defining interfaces start with the word "iface". The next word
is the name of the interface, as used by the ifconfig(8) or route(8)
commands (ie, things like "lo", "eth0", or "ppp0", and "eth1:0").
The interface name is followed by address family the interface uses --
generally this will be "inet" for TCP/IP networking, but there is also
some support for IPX networking ("ipx"), and IPv6 networking ("inet6").
Following that is the method used to configure the interface. In the
example above, this is "static", which means that eth0 is a staticly
allocated IPv4 address.
Further options may follow the "iface" header line on additional lines
in the stanza. These are usually indented for clarity (as in the example)
but are not required to be.
There are currently three standard options available for all interfaces,
regardless of address family or method. These are:
up command
Run command after bringing the interface up. This option can be
given multiple times for a single interface. If so, the commands
will be executed in order. If one of the commands fails, none
of the others will be executed, but the interface will remain
configured. (You can ensure a command never fails by suffixing
"|| true".)
pre-up command
Run command before bringing the interface up. This option can be
given multiple times for a single interface. If so, the commands
will be executed in order. If one of the commands fails, none
of the others will be executed, and the interface will not be
configured. (You can ensure a command never fails by suffixing
"|| true".)
down command
Run command before taking the interface down. This option can be
given multiple times for a single interface. If so, the commands
will be executed in order. If one of the commands fails, none
of the others will be executed, and the interface will not be
deconfigured. (You can ensure a command never fails by suffixing
"|| true".)
post-down command
Run command after taking the interface down. This option can be
given multiple times for a single interface. If so, the commands
will be executed in order. If one of the commands fails, none
of the others will be executed, but the interface will remain
deconfigured. (You can ensure a command never fails by suffixing
"|| true".)
Most methods require additional information, such as address, and netmask;
details about the available methods and the information they
require follows.
This section documents the methods available in the inet address family.
The loopback Method [Toc] [Back]
This method may be used to define the IPv4 loopback interface.
Options [Toc] [Back]
(No options)
The static Method [Toc] [Back]
This method may be used to define ethernet interfaces with statically
allocated IPv4 addresses.
Options [Toc] [Back]
address address
Address (dotted quad) required
netmask netmask
Netmask (dotted quad) required
broadcast broadcast_address
Broadcast address (dotted quad)
network network_address
Network address (dotted quad) required for 2.0.x kernels
gateway address
Default gateway (dotted quad)
pointopoint address
Address of other end point (dotted quad). Note the
spelling of "point-to".
The dhcp Method [Toc] [Back]
This method may be used to obtain an address via DHCP with any of the
tools: dhclient, pump (2.2.x kernels only), or dhcpcd. If you have a
complicated DHCP setup you should note that some of these clients use
their own configuration files, rather than obtaining their configuration
via *ifup*.
Options [Toc] [Back]
hostname hostname
Hostname to be requested (pump, dhcpcd)
leasehours leastime
Preferred lease time in hours (pump)
leasetime leasetime
Preferred lease time in seconds (dhcpcd)
vendor vendor
Vendor class identifier (dhcpcd)
client client_id
Client identifier (dhcpcd)
The bootp Method [Toc] [Back]
This method may be used to obtain an address via bootp.
Options [Toc] [Back]
bootfile file
Tell the server to use file as the bootfile.
server address
Use the IP address address to communicate with the
server.
hwaddr addr
Use addr as the hardware address instead of whatever it
really is.
The ppp Method [Toc] [Back]
This method uses pon/poff to configure a PPP interface. See those commands
for details.
Options [Toc] [Back]
provider name
Use name as the provider (from /etc/ppp/peers).
The wvdial Method [Toc] [Back]
This method uses wvdial to configure a PPP interface. See that command
for ore details.
Options [Toc] [Back]
provider name
Use name as the provider (from /etc/ppp/peers).
This section documents the methods available in the ipx address family.
The static Method [Toc] [Back]
This method may be used to setup an IPX interface.
Options [Toc] [Back]
frame
netnum
The dynamic Method [Toc] [Back]
This method may be used to setup an IPX interface dynamically.
Options [Toc] [Back]
frame
This section documents the methods available in the inet6 address family.
The loopback Method [Toc] [Back]
This method may be used to define the IPv6 loopback interface.
Options [Toc] [Back]
(No options)
The static Method [Toc] [Back]
This method may be used to define interfaces with statically assigned
IPv6 addresses.
Options [Toc] [Back]
address address
Address (colon delimited) required
netmask mask
Netmask (number of bits, eg 64) required
gateway address
Default gateway (colon delimited)
The v4tunnel Method [Toc] [Back]
This method may be used to setup an IPv6-over-IPv4 tunnel. It requires
the ip command from the iproute package.
Options [Toc] [Back]
address address
Address (colon delimited) required
netmask mask
Netmask (number of bits, eg 64) required
endpoint address
Address of other tunnel endpoint (IPv4 dotted quad)
required
gateway address
Default gateway (colon delimited)
The ifupdown suite was written by Anthony Towns <aj@azure.hum-
bug.org.au>. This manpage was contributed by Joey Hess
<joey@kitenet.net>
ifup(8), ifdown(8)
ifupdown August 10 2000 INTERFACES(5)
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