ifquery
parse interface configuration
see also :
ip - ifconfig
Synopsis
ifup
[-nv] [--no-act]
[--verbose] [-i
FILE|--interfaces=FILE]
[--allow CLASS]
-a|IFACE...
ifup -h|--help
ifup -V|--version
ifdown
[-nv] [--no-act]
[--verbose] [-i
FILE|--interfaces=FILE]
[--allow CLASS]
-a|IFACE...
ifquery
[-nv] [--no-act]
[--verbose] [-i
FILE|--interfaces=FILE]
[--allow CLASS]
-a|IFACE...
ifquery
-l|--list [-nv]
[--no-act]
[--verbose] [-i
FILE|--interfaces=FILE]
[--allow CLASS]
-a|IFACE...
add an example, a script, a trick and tips
examples
ifup -a
Bring up all the interfaces defined with auto in
/etc/network/interfaces
ifup eth0
Bring up interface eth0
ifup eth0=home
Bring up interface eth0 as logical interface home
ifdown -a
Bring down all interfaces that are currently up.
ifquery -l
Print names of all interfaces specified with the auto
keyword.
ifquery -l --allow=hotplug
Print names of all interfaces specified with the
allow-hotplug keyword.
ifquery eth0
Display the interface options as specified in the ifupdown
configuration. Each key-value pair is printed out on individual
line using ": " as separator.
source
echo "vdr gets started
again"
start vdr
stop x
start openbox
for INTERFACE in `ifquery --list`;
do restart network-interface INTERFACE=$INTERFACE ; done
initctl emit resume
for INTERFACE in `ifquery --list | grep -v lo`; do grep -q "${INTERFACE}.*dhcp" /etc/network/interfaces
&& dhclient $INTERFACE ; done
description
The ifup
and ifdown commands may be used to configure (or,
respectively, deconfigure) network interfaces based on
interface definitions in the file
/etc/network/interfaces. ifquery command may
be used to parse interfaces configuration.
options
A summary of
options is included below.
-a, --all
If given to ifup, affect
all interfaces marked auto. Interfaces are brought up
in the order in which they are defined in
/etc/network/interfaces. Combined with
--allow, acts on all interfaces of a specified
class instead. If given to ifdown, affect all defined
interfaces. Interfaces are brought down in the order in
which they are currently listed in the state file. Only
interfaces defined in /etc/network/interfaces will be
brought down.
--force
Force configuration or
deconfiguration of the interface.
-h,
--help
Show summary of options.
--allow=CLASS
Only allow interfaces listed in
an allow-CLASS line in
/etc/network/interfaces to be acted upon.
-i FILE,
--interfaces=FILE
Read interface definitions from
FILE instead of from
/etc/network/interfaces.
-X PATTERN,
--exclude=PATTERN
Exclude interfaces from the
list of interfaces to operate on by the PATTERN.
PATTERN uses a usual shell glob syntax. If shell
wildcards are not used, it must match the exact interface
name. This option may be specified multiple times resulting
in more than one pattern being excluded.
-o
OPTION=VALUE
Set OPTION to
VALUE as though it were in
/etc/network/interfaces.
-n,
--no-act
Don’t configure any
interfaces or run any "up" or "down"
commands.
--no-mappings
Don’t run any mappings.
See interfaces(5) for more information about the
mapping feature.
--no-scripts
Don’t run any scripts
under /etc/network/if-*.d/
-V,
--version
Show copyright and version
information.
-v,
--verbose
Show commands as they are
executed.
-l,
--list
For ifquery, list all
the interfaces which match the specified class. If no class
specified, prints all the interfaces listed as
auto.
files
/etc/network/interfaces
definitions of network interfaces See interfaces(5) for
more information.
/run/network/ifstate
current state of network interfaces
known bugs
known bugs limitations
The program keeps records of whether network interfaces are up or
down. Under exceptional circumstances these records can become
inconsistent with the real states of the interfaces. For example,
an interface that was brought up using ifup and later
deconfigured using ifconfig will still be recorded as up.
To fix this you can use the --force option to force
ifup or ifdown to run configuration or
deconfiguration commands despite what it considers the current
state of the interface to be.
The file /run/network/ifstate must be writable for
ifup or ifdown to work properly. If that location
is not writable (for example, because the root filesystem is
mounted read-only for system recovery) then
/run/network/ifstate should be made a symbolic link to a
writable location. If that is not possible then you can use the
--force option to run configuration or deconfiguration
commands without updating the file.
Note that the program does not run automatically: ifup
alone does not bring up interfaces that appear as a result of
hardware being installed and ifdown alone does not bring
down interfaces that disappear as a result of hardware being
removed. To automate the configuration of network interfaces you
need to install other packages such as udev(7) or
ifplugd(8).
notes
ifup, ifdown, and ifquery are actually the
same program called by different names.
The program does not configure network interfaces directly; it
runs low level utilities such as ip to do its dirty work.
When invoked, ifdown checks if ifup is still
running. In that case, SIGTERM is sent to ifup.
see also
interfaces,
ip , ifconfig .
author
The ifupdown
suite was written by Anthony Towns
<aj[:at:]azure.humbug.org[:dot:]au>.