DOKK / manpages / debian 11 / ifupdown2 / ifdown.8.en
IFUP(8) IFUP(8)

ifup - network interface management commands

ifup - bring a network interface up

ifdown - take a network interface down



[-X EXCLUDEPATS] [-f] [-n] [-s] [--print-dependency {list,dot}] [IFACE [IFACE ...]]
[-X EXCLUDEPATS] [-f] [-n] [--print-dependency {list,dot}] [IFACE [IFACE ...]]



ifup and ifdown commands can be used to configure (or, respectively, deconfigure) network interfaces based on interface definitions in the config file ifupdown2.conf (defaults to /etc/network/interfaces/ file).

ifquery(8) maybe used in conjunction with ifup and ifdown commands to query and validate applied/running configuration.

ifup always works on the current interfaces(5) file defined in ifupdown2.conf (default /etc/network/interfaces). ifdown works on the last applied interface configuration.

ifup on an already ifup'ed interface will re-apply the configuration, skipping already applied configuration wherever possible. In many cases where config commands are idempotent, you will see that ifup/ifdown will reapply the config even if the interface already has that config.

ifup and ifdown understands interface dependency order.

For logical interfaces like vlans, bridges, bonds, ifup creates the interface and ifdown deletes the interface. Use --admin-state option if you only want to administratively bring the interface up/down.

When ifup and ifdown are used with interfaces on command line, they must be have a iface section in the interfaces(5) file.



positional arguments:

IFACE interface list separated by spaces. IFACE list and '-a' argument are mutually exclusive.

optional arguments:

show this help message and exit
process all interfaces marked "auto"
verbose
output debug info
ignore non-"allow-CLASS" interfaces
run with all dependent interfaces. This option is redundant when -a is specified. When '-a' is specified, interfaces are always executed in dependency order.
Exclude interfaces from the list of interfaces to operate on. Can be specified multiple times If the excluded interface has dependent interfaces, (e.g. a bridge or a bond with multiple enslaved interfaces) then each dependent interface must be specified in order to be excluded.
Uses interfaces file instead of default defined in ifupdown2.conf (default /etc/network/interfaces). Also in ifupdown2.conf, users are not allowed to specify their own interfaces file unless disable_cli_interfacesfile is set to 0 (default is 1).

interfaces file format

force run all operations
print out what would happen, but don't do it

print iface dependency in list or dot format

don't run any addon modules/scripts. Only bring the interface administratively up/down
By default ifdown looks at the saved state for interfaces to bring down. This option allows ifdown to look at the current interfaces file. Useful when your state file is corrupted or you want down to use the latest from the interfaces file
Only run the interfaces file parser



# bringing up all interfaces
ifup -a


# bringing up interface list

ifup swp1 swp2


# bringing up interface with its dependents

ifup br0 --with-depends


# bringing down all interfaces

ifdown -a


# bringing down a single interface

ifdown swp1


# excluding interfaces using -X option

ifdown -X eth0 -a

ifup -X eth0 -a

ifdown -X eth0 -X lo -a



# using verbose -v option to see what is going on

ifup -v -a


# using debug -d option to see more of what is going on

ifup -d -a


# ignore errors

ifup -a -f

ifdown -a -f



# run ifdown and ifup on all interfaces using service command/init script

service networking restart


# run ifup on all interfaces using service command/init script

service networking start


# ifdown on all interfaces using service command/init script

service networking stop


# To run ifup/ifdown on only interfaces that changed see ifreload(8)



ifquery(8), ifreload(8), interfaces(5), ifupdown-addons-interfaces(5)


Roopa Prabhu <roopa@cumulusnetworks.com>

Copyright 2014 Cumulus Networks, Inc. All rights reserved.

2014-02-05 0.1