конфигурация сетевого устройства (Network device configuration)
Описание (Description)
A plain ini-style text file that encodes configuration for
matching network devices, used by systemd-udevd(8) and in
particular its net_setup_link builtin. See systemd.syntax(7) for
a general description of the syntax.
The link files are read from the files located in the system
network directory /usr/lib/systemd/network, the volatile runtime
network directory /run/systemd/network, and the local
administration network directory /etc/systemd/network. Link files
must have the extension .link; other extensions are ignored. All
link files are collectively sorted and processed in lexical
order, regardless of the directories in which they live. However,
files with identical filenames replace each other. Files in /etc/
have the highest priority, files in /run/ take precedence over
files with the same name in /usr/lib/. This can be used to
override a system-supplied link file with a local file if needed.
As a special case, an empty file (file size 0) or symlink with
the same name pointing to /dev/null disables the configuration
file entirely (it is "masked").
Along with the link file foo.link, a "drop-in" directory
foo.link.d/ may exist. All files with the suffix ".conf" from
this directory will be merged in the alphanumeric order and
parsed after the main file itself has been parsed. This is useful
to alter or add configuration settings, without having to modify
the main configuration file. Each drop-in file must have
appropriate section headers.
In addition to /etc/systemd/network, drop-in ".d" directories can
be placed in /usr/lib/systemd/network or /run/systemd/network
directories. Drop-in files in /etc/ take precedence over those in
/run/ which in turn take precedence over those in /usr/lib/.
Drop-in files under any of these directories take precedence over
the main link file wherever located.
The link file contains a [Match] section, which determines if a
given link file may be applied to a given device, as well as a
[Link] section specifying how the device should be configured.
The first (in lexical order) of the link files that matches a
given device is applied. Note that a default file 99-default.link
is shipped by the system. Any user-supplied .link should hence
have a lexically earlier name to be considered at all.
See udevadm(8) for diagnosing problems with .link files.
