「interfaces-old」

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/etc/network/interfaces : ifup(man 8) 和 ifdown(man 8) 命令所使用的配置文件;

注释

`#’ 来注释行;不支持行尾注释,注释必须独占一行;

`\’ 用在行尾表示换行;

文件组成

文件由组成”iface”, “mapping”, “auto”, “allow-“, “source” and “source-directory” 关键字开始的小节组成。例如:

auto eth0

allow-hotplug eth1

source interfaces.d/machine-dependent

source-directory interfaces.d

iface eth0 inet dhcp

iface eth0 inet6 auto

mapping eth1
script /usr/local/sbin/map-scheme

map HOME eth0-home

map WORK eth0-work

iface eth1-home inet static
address 192.168.1.2/24

gateway 192.168.1.1

up flush-mail

iface eth1-work inet dhcp

auto

以 ”
auto” 开始的行,表示网卡会在执行
ifup -a 时启动。(系统启动脚本中使用了这个选项。)

网卡名要跟在 ”
auto” 后面。可以有多个 ”
auto” 部分。按照顺序,依次启动网卡。

allow-

以 “allow-” 开始的行,表示网卡会被各个子系统启动。This may be done using a command such as “ifup –allow=hotplug eth0 eth1”, which

will only bring up eth0 or eth1 if it is listed in an “allow-hotplug” line. Note that “allow-auto” 与 “auto” 同义.

no-auto-down

以 “no-auto-down” 开始的行,表示这些网口在执行 ifdown -a 时不关闭。

主要用在系统关机时,防止网口的关闭,比如 如果”根文件系统”是”网络文件系统” ,那就应该等到最后。

不过,仍然可以通过指定网口名的方式关闭;

no-scripts

以 ”
no-scripts” 开始的行,表示这些接口在启动和关闭的时候不执行
/etc/network/if-*.d/ 下的脚本。

source & source-directory

“source” 关键字用于从其他文件引入内容。用法:source path/to/file。文件支持 Shell 通配符。(man 3 wordexp)

“source-directory” 关键字用于一次引入文件夹中多个文件,文件名要匹配: ^[a-zA-Z0-9_-]+$. 文件夹路径也可以使用shell通配符;

如果引入的文件或者文件夹不是绝对路径, 则相对于当前文件所在的文件夹。例如 如果是/etc/network/interfaces,那相对路径 则是 /etc/network.

目前(07/30/2016), network-manager 和 guessnet 不支持 “source-directory” .

mapping

Stanzas beginning with the word “mapping” are used to determine how a logical interface name is chosen

for a physical interface that is to be brought up. The first line of a mapping stanza consists of the

word “mapping” followed by a pattern in shell glob syntax. Each mapping stanza must contain a script

definition. The named script is run with the physical interface name as its argument and with the

contents of all following “map” lines (without the leading “map”) in the stanza provided to it on its

standard input. The script must print a string on its standard output before exiting. See

/usr/share/doc/ifupdown/examples for examples of what the script must print.

Mapping a name consists of searching the remaining mapping patterns and running the script correspond‐

ing to the first match; the script outputs the name to which the original is mapped.

ifup is normally given a physical interface name as its first non-option argument. ifup also uses

this name as the initial logical name for the interface unless it is accompanied by a suffix of the

form =LOGICAL, in which case ifup chooses LOGICAL as the initial logical name for the interface. It

then maps this name, possibly more than once according to successive mapping specifications, until no

further mappings are possible. If the resulting name is the name of some defined logical interface

then ifup attempts to bring up the physical interface as that logical interface. Otherwise ifup exits

with an error.

Stanzas defining logical interfaces start with a line consisting of the word “iface” followed by the

name of the logical interface. In simple configurations without mapping stanzas this name should sim‐

ply be the name of the physical interface to which it is to be applied. (The default mapping script

is, in effect, the echo command.) The interface name is followed by the name of the address family

that the interface uses. 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 name of the method

used to configure the interface.

Additional options can be given on subsequent lines in the stanza. Which options are available

depends on the family and method, as described below. Additional options can be made available by

other Debian packages. For example, the wireless-tools package makes available a number of options

prefixed with “wireless-” which can be used to configure the interface using iwconfig(8). (See wire‐

less(7) for details.)

Options are usually indented for clarity (as in the example above) but are not required to be.

Multiple “iface” stanzas can be given for the same interface, in which case all of the configured

addresses and options for that interface will be applied when bringing up that interface. This is

useful to configure both IPv4 and IPv6 addresses on the same interface (although if no inet6 stanza is

present, the kernel will normally still perform stateless address autoconfiguration if there is an

IPv6 route advertisement daemon on the network). It can also be used to configure multiple addresses

of the same type on a single interface.

INTERFACE TEMPLATES

It is possible to define interface definition templates and extend them using the
inherits keyword:

iface ethernet inet static
mtu 1500

hwaddress 11:22:33:44:55:66

iface eth0 inet static inherits ethernet
address 192.168.1.2/24

This may be useful to separate link-level settings shared by multiple interfaces from, for example, IP

address settings specific to every interface.

VLAN AND BRIDGE INTERFACES

To ease the configuration of VLAN interfaces, interfaces having . (full stop character) in the name

are configured as 802.1q tagged virtual LAN interface. For example, interface eth0.1 is a virtual

interface having eth0 as physical link, with VLAN ID 1.

For compatibility with bridge-utils package, if bridge_ports option is specified, VLAN interface con‐

figuration is not performed.

IFACE OPTIONS

The following “command” options are available for every family and method. Each of these options can

be given multiple times in a single stanza, in which case the commands are executed in the order in

which they appear in the stanza. (You can ensure a command never fails by suffixing them with “||

true”.)

pre-up command
Run command before bringing the interface up. If this command fails then ifup aborts, refrain‐

ing from marking the interface as configured, prints an error message, and exits with status 0.

This behavior may change in the future.

up command

post-up command
Run command after bringing the interface up. If this command fails then ifup aborts, refrain‐

ing from marking the interface as configured (even though it has really been configured),

prints an error message, and exits with status 0. This behavior may change in the future.

down command

pre-down command
Run command before taking the interface down. If this command fails then ifdown aborts, marks

the interface as deconfigured (even though it has not really been deconfigured), and exits with

status 0. This behavior may change in the future.

post-down command
Run command after taking the interface down. If this command fails then ifdown aborts, marks

the interface as deconfigured, and exits with status 0. This behavior may change in the

future.

description name
Alias interface by name

There exists for each of the above mentioned options a directory /etc/network/if-<option>.d/ the

scripts in which are run (with no arguments) using run-parts(8) after the option itself has been pro‐

cessed. Please note that as post-up and pre-down are aliases, no files in the corresponding directo‐

ries are processed. Please use if-up.d and if-down.d directories instead.

All of these commands have access to the following environment variables.

IFACE The physical name of the interface being processed, or “–all” (see below).

LOGICAL
The logical name of the interface being processed, or “auto” (see below).

ADDRFAM
The address family of the interface, or “meta” (see below).

METHOD The method of the interface (e.g., static), or “none” (see below).

MODE start if run from ifup, stop if run from ifdown.

PHASE As per MODE, but with finer granularity, distinguishing the pre-up, post-up, pre-down and post-
down phases.

VERBOSITY
Indicates whether –verbose was used; set to 1 if so, 0 if not.

PATH The command search path: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

Additionally, all options given in an interface definition stanza are exported to the environment in

upper case with “IF_” prepended and with hyphens converted to underscores and non-alphanumeric charac‐

ters discarded.

When ifupdown is being called with the –all option, before doing anything to interfaces, if calls all

the hook scripts (pre-up or down) with IFACE set to “–all”, LOGICAL set to the current value of

–allow parameter (or “auto” if it’s not set), ADDRFAM=”meta” and METHOD=”none”. After all the inter‐

faces have been brought up or taken down, the appropriate scripts (up or post-down) are executed.

OPTIONS PROVIDED BY OTHER PACKAGES

This manual page documents the configuration options provided by the ifupdown package. However, other

packages can make other options available for use in /etc/network/interfaces. Here is a list of pack‐

ages that provide such extensions:

arping, avahi-autoipd, avahi-daemon, bind9, bridge-utils, clamav-freshclam, controlaula, epoptes-

client, ethtool, guidedog, hostap-utils, hostapd, htpdate, ifenslave, ifmetric, ifupdown-extra, ifup‐

down-multi, ifupdown-scripts-zg2, initscripts, isatapd, linux-wlan-ng, lprng, macchanger, miredo,

nslcd, ntpdate, openntpd, openresolv, openssh-server, openvpn, openvswitch-switch, postfix, resolv‐

conf, sendmail-base, shorewall-init, slrn, slrnpull, tinc, ucarp, uml-utilities, uruk, vde2, vlan,

vzctl, whereami, wide-dhcpv6-client, wireless-tools, wpasupplicant.

Please consult the documentation of those packages for information about how they extend ifupdown.

INET ADDRESS FAMILY

This section documents the methods available in the inet address family.

The loopback Method

This method may be used to define the IPv4 loopback interface.

Options

(No options)

The static Method

This method may be used to define Ethernet interfaces with statically allocated IPv4 addresses.

Options

address address
Address (dotted quad/netmask) required

netmask mask
Netmask (dotted quad or CIDR)

broadcast broadcast_address
Broadcast address (dotted quad, + or -). Default value: “+”

metric metric
Routing metric for default gateway (integer)

gateway address
Default gateway (dotted quad)

pointopoint address
Address of other end point (dotted quad). Note the spelling of “point-to”.

hwaddress address
Link local address or “random”.

mtu size
MTU size

scope Address validity scope. Possible values: global, link, host

The manual Method

This method may be used to define interfaces for which no configuration is done by default. Such

interfaces can be configured manually by means of up and down commands or /etc/network/if-*.d scripts.

Options

hwaddress address
Link local address or “random”.

mtu size
MTU size

The dhcp Method

This method may be used to obtain an address via DHCP with any of the tools: dhclient, pump, udhcpc,

dhcpcd. (They have been listed in their order of precedence.) If you have a complicated DHCP setup you

should note that some of these clients use their own configuration files and do not obtain their con‐

figuration information via ifup.

Options

hostname hostname
Hostname to be requested (pump, dhcpcd, udhcpc)

metric metric
Metric for added routes (dhclient)

leasehours leasehours
Preferred lease time in hours (pump)

leasetime leasetime
Preferred lease time in seconds (dhcpcd)

vendor vendor
Vendor class identifier (dhcpcd)

client client
Client identifier (dhcpcd)

hwaddress address
Hardware address.

The bootp Method

This method may be used to obtain an address via bootp.

Options

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 tunnel Method

This method is used to create GRE or IPIP tunnels. You need to have the ip binary from the iproute

package. For GRE tunnels, you will need to load the ip_gre module and the ipip module for IPIP tun‐

nels.

Options

address address
Local address (dotted quad) required

mode type
Tunnel type (either GRE or IPIP) required

endpoint address
Address of other tunnel endpoint required

dstaddr address
Remote address (remote address inside tunnel)

local address
Address of the local endpoint

metric metric
Routing metric for default gateway (integer)

gateway address
Default gateway

ttl time
TTL setting

mtu size
MTU size

The ppp Method

This method uses pon/poff to configure a PPP interface. See those commands for details.

Options

provider name
Use name as the provider (from /etc/ppp/peers).

unit number
Use number as the ppp unit number.

options string
Pass string as additional options to pon.

The wvdial Method

This method uses wvdial to configure a PPP interface. See that command for more details.

Options

provider name
Use name as the provider (from /etc/wvdial.conf).

The ipv4ll Method

This method uses avahi-autoipd to configure an interface with an IPv4 Link-Layer address

(169.254.0.0/16 family). This method is also known as APIPA or IPAC, and often colloquially referred

to as “Zeroconf address”.

Options

(No options)

IPX ADDRESS FAMILY

This section documents the methods available in the ipx address family.

The static Method

This method may be used to setup an IPX interface. It requires the ipx_interface command.

Options

frame type
type of Ethernet frames to use (e.g. 802.2)

netnum id
Network number

The dynamic Method

This method may be used to setup an IPX interface dynamically.

Options

frame type
type of Ethernet frames to use (e.g. 802.2)

INET6 ADDRESS FAMILY

This section documents the methods available in the inet6 address family.

The auto Method

This method may be used to define interfaces with automatically assigned IPv6 addresses. Using this

method on its own doesn’t mean that RDNSS options will be applied, too. To make this happen, rdnssd

daemon must be installed, properly configured and running. If stateless DHCPv6 support is turned on,

then additional network configuration parameters such as DNS and NTP servers will be retrieved from a

DHCP server. Please note that on ifdown, the lease is not currently released (a known bug).

Options

privext int
Privacy extensions (RFC4941) (0=off, 1=assign, 2=prefer)

accept_ra int
Accept router advertisements (0=off, 1=on, 2=on+forwarding). Default value: “2”

dhcp int
Use stateless DHCPv6 (0=off, 1=on)

request_prefix int
Request a prefix through DHCPv6 Prefix Delegation (0=off, 1=on). Default value: “0”

ll-attempts
Number of attempts to wait for a link-local address. Default value: “60”

ll-interval
Link-local address polling interval in seconds. Default value: “0.1”

The loopback Method

This method may be used to define the IPv6 loopback interface.

Options

(No options)

The static Method

This method may be used to define interfaces with statically assigned IPv6 addresses. By default,

stateless autoconfiguration is disabled for this interface.

Options

address address
Address (colon delimited/netmask) required

netmask mask
Netmask (number of bits, eg 64)

metric metric
Routing metric for default gateway (integer)

gateway address
Default gateway (colon delimited)

media type
Medium type, driver dependent

hwaddress address
Hardware address or “random”

mtu size
MTU size

accept_ra int
Accept router advertisements (0=off, 1=on, 2=on+forwarding)

autoconf int
Perform stateless autoconfiguration (0=off, 1=on). Default value: “0”

privext int
Privacy extensions (RFC3041) (0=off, 1=assign, 2=prefer)

scope Address validity scope. Possible values: global, site, link, host

preferred-lifetime int
Time that address remains preferred

dad-attempts
Number of attempts to settle DAD (0 to disable DAD). Default value: “60”

dad-interval
DAD state polling interval in seconds. Default value: “0.1”

The manual Method

This method may be used to define interfaces for which no configuration is done by default. Such

interfaces can be configured manually by means of up and down commands or /etc/network/if-*.d scripts.

Options

hwaddress address
Hardware address or “random”

mtu size
MTU size

The dhcp Method

This method may be used to obtain network interface configuration via stateful DHCPv6 with dhclient.

In stateful DHCPv6, the DHCP server is responsible for assigning addresses to clients.

Options

hwaddress address
Hardware address or “random”

accept_ra int
Accept router advertisements (0=off, 1=on, 2=on+forwarding). Default value: “1”

autoconf int
Perform stateless autoconfiguration (0=off, 1=on)

request_prefix int
Request a prefix through DHCPv6 Prefix Delegation (0=off, 1=on). Default value: “0”

ll-attempts
Number of attempts to wait for a link-local address. Default value: “60”

ll-interval
Link-local address polling interval in seconds. Default value: “0.1”

The v4tunnel Method

This method may be used to setup an IPv6-over-IPv4 tunnel. It requires the ip command from the iproute

package.

Options

address address
Address (colon delimited) required

netmask mask
Netmask (number of bits, eg 64)

endpoint address
Address of other tunnel endpoint (IPv4 dotted quad) required

local address
Address of the local endpoint (IPv4 dotted quad)

metric metric
Routing metric for default gateway (integer)

gateway address
Default gateway (colon delimited)

ttl time
TTL setting

mtu size
MTU size

preferred-lifetime int
Time that address remains preferred

The 6to4 Method

This method may be used to setup an 6to4 tunnel. It requires the ip command from the iproute package.

Options

local address
Address of the local endpoint (IPv4 dotted quad) required

metric metric
Routing metric for default gateway (integer)

ttl time
TTL setting

mtu size
MTU size

preferred-lifetime int
Time that address remains preferred

CAN ADDRESS FAMILY

This section documents the methods available in the can address family.

The static Method

This method may be used to setup an Controller Area Network (CAN) interface. It requires the the ip

command from the iproute package.

Options

bitrate bitrate
bitrate (1..1000000) required

samplepoint samplepoint
sample point (0.000..0.999)

loopback loopback
loop back CAN Messages (on|off)

listenonly listenonly
listen only mode (on|off)

triple triple
activate triple sampling (on|off)

oneshot oneshot
one shot mode (on|off)

berr berr
activate berr reporting (on|off)

KNOWN BUGS/LIMITATIONS

The ifup and ifdown programs work with so-called “physical” interface names. These names are assigned

to hardware by the kernel. Unfortunately it can happen that the kernel assigns different physical

interface names to the same hardware at different times; for example, what was called “eth0” last time

you booted is now called “eth1” and vice versa. This creates a problem if you want to configure the

interfaces appropriately. A way to deal with this problem is to use mapping scripts that choose logi‐

cal interface names according to the properties of the interface hardware. See the get-mac-address.sh

script in the examples directory for an example of such a mapping script. See also Debian bug

#101728.

SEE ALSO

ifup(8), ip(8), ifconfig(8), run-parts(8), resolvconf(8).

For advice on configuring this package read the Network Configuration chapter of the Debian Reference

manual, available at
http://www.debian.org/doc/manuals/debian-reference/ch05.en.html or in the debian-

reference-en package.

Examples of how to set up interfaces can be found in /usr/share/doc/ifupdown/examples/network-interfaces.gz.

参考文献

man 5 interfaces