interfaces

INTERFACES(5) File formats INTERFACES(5)

NAME

   /etc/network/interfaces - network interface configuration for ifup and ifdown

DESCRIPTION

   /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.

EXAMPLE

   The following example configures two network interfaces: eth0 is brought up at boot, and uses DHCP for IPv4 and SLAAC for IPv6, whereas eth1 is brought up whenever the  network  hard
   ware is detected, and is configured with static IPv4 and IPv6 addresses.

   auto eth0
   allow-hotplug eth1

   iface eth0 inet dhcp

   iface eth0 inet6 auto

   iface eth1 inet static
        address 192.168.1.2/24
        gateway 192.168.1.1

   iface eth1 inet6 static
        address fec0:0:0:1::2/64
        gateway fec0:0:0:1::1

FILE FORMAT

   Lines starting with `#' are ignored. Note that end-of-line comments are NOT supported, comments must be on a line of their own.

   A line may be extended across multiple lines by making the last character a backslash.

   The file consists of zero or more "iface", "mapping", "auto", "allow-", "rename", "source" and "source-directory" stanzas. These will be described in more detail in the following sec
   tions.

INTERFACE SELECTION

   Lines  beginning  with the word "auto" are used to identify the physical interfaces to be brought up when ifup is run with the -a option.  (This option is also used by the system boot
   scripts, so interfaces marked "auto" are brought up at boot time.)  Physical interface names should follow the word "auto" on the same line.  There can  be  multiple  "auto"  stanzas.
   ifup brings the named interfaces up in the order listed.

   Lines  beginning  with  "allow-"  are  used  to identify interfaces that should be brought up automatically by various subsystems. This may be done using a command such as "ifup --al‐
   low=hotplug eth0 eth1", which will only bring up eth0 or eth1 if it is listed in an "allow-hotplug" line. Note that "allow-auto" and "auto" are synonyms.  (Interfaces  marked  "allow-
   hotplug"  are  brought  up  when udev detects them.  This can either be during boot if the interface is already present, or at a later time, for example when plugging in a USB network
   card.  Please note that this does not have anything to do with detecting a network cable being plugged in.)

   Lines beginning with "no-auto-down" are used to identify interfaces that should not be brought down by the command "ifdown -a". Its main use is to  prevent  an  interface  from  being
   brought down during system shutdown time, for example if the root filesystem is a network filesystem and the interface should stay up until the very end. Note that you can still bring
   down the interface by specifying the interface name explicitly.

   Lines  beginning  with "no-scripts" are used to identify interfaces for which scripts in /etc/network/if-*.d/ should not be run when those interfaces are brought up or down.  he above
   will match eth0 and eth1, and will bring up both interfaces using the "iface eth" stanza.

INTERFACE RENAMING

   Lines beginning with "rename" are used to rename interfaces.  It takes one or more arguments in the form of "CUR=NEW", where CUR is the name of an existing interface, and NEW  is  the
   new name.  This becomes very powerful when combined with pattern matching for the CUR interface.

   Interfaces  are  renamed  whenever "ifup" is called.  Renaming logically happens before anything else is done.  So if an interface is started with the name "foo", and it has to be re
   named to "bar" and brought up at boot time, then one should use the following /etc/network/interfaces file:

   rename foo=bar
   auto bar
   iface bar ...

   However, if the interface is not renamed yet, it is possible to use both "ifup foo" and "ifup bar".  The former command will then automatically be converted to the  latter.   This  is
   mainly useful when ifup is called automatically whenever an interface is hotplugged.

   Interface  renaming  only works if the operating system supports it, if an interface is not renamed to another existing interface, and may require that the interface that is to be re
   named has not been brought up yet.  If ifup tries to rename an interface and it fails, it will exit with an error.

INCLUDING OTHER FILES

   Lines beginning with "source" are used to include stanzas from other files, so configuration can be split into many files. The word "source" is followed by the  path  of  file  to  be
   sourced. Shell wildcards can be used.  (See wordexp(3) for details.)

   Similarly,  "source-directory"  keyword  is  used to source multiple files at once, without specifying them individually or using shell globs. Additionally, when "source-directory" is
   used, names of the files are checked to match the following regular expression: ^[a-zA-Z0-9_-]+$. In other words, the names must consist entirely of ASCII upper- and  lower-case  let
   ters, ASCII digits, ASCII underscores, and ASCII minus-hyphens. In the directory path, shell wildcards may be used as well.

   When  sourcing files or directories, if a path doesn't have a leading slash, it's considered relative to the directory containing the file in which the keyword is placed. In the exam
   ple above, if the file is located at /etc/network/interfaces, paths to the included files are understood to be under /etc/network.

   By default, on a freshly installed Debian system, the interfaces file includes a line to source files in the /etc/network/interfaces.d directory.

MAPPINGS

   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 in
   terface 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 corresponding 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 succes
   sive  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.

INTERFACE DEFINITIONS

   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 simply 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 fol
   lowed 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  net
   working ("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 wireless(7) for details.)  A list of packages providing additional options is mentioned in the section "OPTIONS PROVIDED BY OTHER PACKAGE".

   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 inter
   face.  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.

PATTERN MATCHING INTERFACES

   It is possible to use patterns to match one or more real interfaces.  These patterns can currently appear in lines beginning with "auto", "allow-", "rename" and on the  command  line.
   A pattern has the following format (see below for exceptions for GNU/Hurd):

   [VARIABLE]/VALUE[/[OPTIONS]][=LOGICAL]

   If no VARIABLE is given, this pattern will match interface names against the given VALUE.  VALUE can contain wildcard patterns such as ? and *, see the fnmatch(3) function.  When ifup
   or  ifdown is run, patterns are replaces by all real interfaces that are currently known to the operating system kernel and whose names match the pattern.  For example, given the fol
   lowing line:

   auto /eth*

   If the kernel knows about the interfaces with names lo, eth0 and eth1, then the above line is then interpreted as:

   auto eth0 eth1

   Note that there must still be valid "iface" stanzas for each matching interface.  However, it is possible to combine a pattern with a mapping to a logical interface, like so:

   auto /eth*=eth
   iface eth inet dhcp

   Valid variable names are "mac", in which case value is matched against the interface's MAC address.  On Linux, the variable name can also be any filename  in  /sys/class/net/<iface>/,
   in which case the value is matched against the contents of the corresponding file.

   The  OPTIONS  field currently only supports a number. If given, only the n-th interface that has a matching value will actually be used, where n is the number given, starting at 1. So
   /eth*/1 will match the first interface whose name starts with eth.

   On GNU/Hurd, interface names start with /dev/, and this obviously clashes with the format for patterns.  To ensure an interface name like /dev/eth0 does not get interpreted as a  pat
   tern,  any  pattern  that starts with /dev/ is ignored, and instead interpreted as a literal interface name.  To make a pattern that matches interface names on GNU/Hurd, use something
   like:

   auto /?dev?eth*=eth
   iface eth inet dhcp

VLAN 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 with VLAN ID 1 having eth0 as its parent interface.

   VLAN  interfaces are mostly treated as independent interfaces.  As such, a VLAN interface is normally not automatically brought up when its parent interface is brought up.  The excep
   tion is when ifup is called with the --allow option, in which case all VLAN interfaces that are in the same allow class as the parent interface are brought up together with the parent
   interface.  For example:

   allow-hotplug eth0 eth0.1

   iface eth0 inet static
        address ...

   iface eth0.1 inet static
        address ...

   iface eth0.2 inet static
        address ...

   In the above example, when "ifup --allow hotplug eth0" is called (either manually or because udev triggers this when a network device is hotplugged), the interface eth0 and  the  VLAN
   interface eth0.1 are brought up, but eth0.2 is not.

   Keep  in mind that pattern matching will only match interfaces the kernel knows about, so it is not possible to specify "auto /eth0.*" and have all VLAN interfaces for eth0 be brought
   up at boot time.  Another way to ensure that a VLAN interface is brought up automatically when the parent interface is brought up, is to use a recursive call to ifup, like so:

   iface eth0 inet manual
        up ifup eth0.3

   iface eth0.3 inet static
        address ...

   Note that there is no need to add an explicit call to ifdown, since VLAN interfaces are automatically brought down whenever their parent interfaces are brought down.

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  exe
   cuted 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, refraining 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, refraining from marking the interface as configured (even though it has really  been  con
          figured), 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

HOOK SCRIPTS

   There are four directories in which scripts can be placed which will always be run for any interface during certain phases of ifup and ifdown commands. These are:

   /etc/network/if-pre-up.d/
          Scripts in this directory are run before bringing the interface up.

   /etc/network/if-up.d/
          Scripts in this directory are run after bringing the interface up.

   /etc/network/if-down.d/
          Scripts in this directory are run before bringing the interface down.

   /etc/network/if-post-down.d/
          Scripts in this directory are run after bringing the interface down.

   The scripts in which are run (with no arguments) using run-parts(8) after the corresponding pre-up, up, down and post-down options in the /etc/network/interfaces file itself have been
   processed. Please note that as post-up and pre-down are aliases, no files in the corresponding directories are processed.  Please use if-up.d and if-down.d directories instead.

ENVIRONMENT VARIABLES

   All hook scripts, and the commands executed by pre-up, up, post-up, pre-down, down and post-down 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).

   CLASS  The  class of interfaces being processed.  This is a copy of the value given to the --allow option when running ifup or ifdown, otherwise it is set to "auto" when the --all op
          tion is used.

   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 characters discarded.

   When  ifupdown is being called with the --all option, before doing anything to interfaces, it 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 interfaces have been brought up or taken down, the appropriate scripts
   (up or post-down) are executed.

CONCURRENCY AND PARALLEL EXECUTION

   Ifupdown uses per-interface locking to ensure that concurrent ifup and ifdown calls to the same interface are run in serial.  However, calls to different interfaces will  be  able  to
   run in parallel.  It is therefore important that any hook scripts and pre-up, up, down and post-down commands are written with the possibility of parallel execution in mind.

   It  is  allowed  to recursively call ifup and ifdown from hook scripts and interface commands, as long as these calls refer to a different interface than the one that is already being
   (de)configured.  Loops are detected and will result in the call failing instead of a deadlock, although it is best if one does not rely on that.

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 packages 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, ifup
   down-extra, ifupdown-multi, ifupdown-scripts-zg2, initscripts, isatapd, linux-wlan-ng, lprng, macchanger, miredo, nslcd, ntpdate, openntpd, openresolv, openssh-server, openvpn,  open
   vswitch-switch,  postfix, resolvconf, 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 number of bits) deprecated

          broadcast broadcast_address
                 Broadcast address (dotted quad, + or -) deprecated. 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/net
   work/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, 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 configuration information via ifup.

   Options

          hostname hostname
                 Hostname to be requested (dhcpcd, udhcpc)

          metric metric
                 Metric for added routes (dhclient)

          leasetime leasetime
                 Preferred lease time in seconds (dhcpcd)

          vendor vendor_id
                 Vendor class identifier (dhcpcd)

          client client_id
                 Client identifier (dhcpcd), or "no" (dhclient)

          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  mod
   ule for IPIP tunnels.

   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) deprecated

          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/net
   work/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 tunnel Method

   This method is used to create IP6GRE, IP6IP6 or IPIP6 tunnels. You need to have the ip binary from the iproute package. For IP6GRE tunnels, you will need to load  the  ip6_gre  module
   and the ip6_tunnel module for IP6IP6 or IPIP6 tunnels.

   Options

          address address
                 Local Address (colon delimited)

          netmask mask
                 Netmask (number of bits, eg 64)

          mode type
                 Tunnel type (either IP6GRE, IP6IP6 or IPIP6) required

          endpoint address
                 Address of other tunnel endpoint (colon delimited) required

          dstaddr address
                 Remote address (remote address inside tunnel)

          local address
                 Address of the local endpoint (colon delimited)

          metric metric
                 Routing metric for default gateway (integer)

          gateway address
                 Default gateway (colon delimited)

          ttl time
                 TTL setting

          mtu size
                 MTU size

          encaplimit limit
                 Encapsulation limit ("none" or integer)

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/netmask) required

          netmask mask
                 Netmask (number of bits, eg 64) deprecated

          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 a 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 a 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)

          restart-ms restart-ms
                 restart-ms (0..)

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 logical interface names according to the  prop
   erties 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.

AUTHOR

   The ifupdown suite was written by Anthony Towns <aj@azure.humbug.org.au>.  This manpage was contributed by Joey Hess <joey@kitenet.net>.

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-refer
   ence/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.

ifupdown 24 July 2017 INTERFACES(5)