focal (5) networkd.conf.5.gz

Provided by: systemd_245.4-4ubuntu3.24_amd64 bug

NAME
       networkd.conf, networkd.conf.d - Global Network configuration files


SYNOPSIS
       /etc/systemd/networkd.conf

       /etc/systemd/networkd.conf.d/*.conf

       /lib/systemd/networkd.conf.d/*.conf


DESCRIPTION
       These configuration files control global network parameters. Currently the DHCP Unique Identifier (DUID).


CONFIGURATION DIRECTORIES AND PRECEDENCE
       The default configuration is defined during compilation, so a configuration file is only needed when it
       is necessary to deviate from those defaults. By default, the configuration file in /etc/systemd/ contains
       commented out entries showing the defaults as a guide to the administrator. This file can be edited to
       create local overrides.

       When packages need to customize the configuration, they can install configuration snippets in
       /usr/lib/systemd/*.conf.d/ or /usr/local/lib/systemd/*.conf.d/. The main configuration file is read
       before any of the configuration directories, and has the lowest precedence; entries in a file in any
       configuration directory override entries in the single configuration file. Files in the *.conf.d/
       configuration subdirectories are sorted by their filename in lexicographic order, regardless of in which
       of the subdirectories they reside. When multiple files specify the same option, for options which accept
       just a single value, the entry in the file with the lexicographically latest name takes precedence. For
       options which accept a list of values, entries are collected as they occur in files sorted
       lexicographically.

       Files in /etc/ are reserved for the local administrator, who may use this logic to override the
       configuration files installed by vendor packages. It is recommended to prefix all filenames in those
       subdirectories with a two-digit number and a dash, to simplify the ordering of the files.

       To disable a configuration file supplied by the vendor, the recommended way is to place a symlink to
       /dev/null in the configuration directory in /etc/, with the same filename as the vendor configuration
       file.


[NETWORK] SECTION OPTIONS
       The following options are available in the "[Network]" section:

       SpeedMeter=
           Takes a boolean. If set to yes, then systemd-networkd measures the traffic of each interface, and
           networkctl status INTERFACE shows the measured speed. Defaults to no.

       SpeedMeterIntervalSec=
           Specifies the time interval to calculate the traffic speed of each interface. If SpeedMeter=no, the
           value is ignored. Defaults to 10sec.


[DHCP] SECTION OPTIONS
       This section configures the DHCP Unique Identifier (DUID) value used by DHCP protocol. DHCPv6 client
       protocol sends the DHCP Unique Identifier and the interface Identity Association Identifier (IAID) to a
       DHCP server when acquiring a dynamic IPv6 address. DHCPv4 client protocol sends IAID and DUID to the DHCP
       server when acquiring a dynamic IPv4 address if ClientIdentifier=duid. IAID and DUID allows a DHCP server
       to uniquely identify the machine and the interface requesting a DHCP IP. To configure IAID and
       ClientIdentifier, see systemd.network(5).

       The following options are understood:

       DUIDType=
           Specifies how the DUID should be generated. See RFC 3315[1] for a description of all the options.

           The following values are understood:

           vendor
               If "DUIDType=vendor", then the DUID value will be generated using "43793" as the vendor
               identifier (systemd) and hashed contents of machine-id(5). This is the default if DUIDType= is
               not specified.

           uuid
               If "DUIDType=uuid", and DUIDRawData= is not set, then the product UUID is used as a DUID value.
               If a system does not have valid product UUID, then an application-specific machine-id(5) is used
               as a DUID value. About the application-specific machine ID, see
               sd_id128_get_machine_app_specific(3).

           link-layer-time[:TIME], link-layer
               If "link-layer-time" or "link-layer" is specified, then the MAC address of the interface is used
               as a DUID value. The value "link-layer-time" can take additional time value after a colon, e.g.
               "link-layer-time:2018-01-23 12:34:56 UTC". The default time value is "2000-01-01 00:00:00 UTC".

           In all cases, DUIDRawData= can be used to override the actual DUID value that is used.

       DUIDRawData=
           Specifies the DHCP DUID value as a single newline-terminated, hexadecimal string, with each byte
           separated by ":". The DUID that is sent is composed of the DUID type specified by DUIDType= and the
           value configured here.

           The DUID value specified here overrides the DUID that systemd-networkd.service(8) generates from the
           machine ID. To configure DUID per-network, see systemd.network(5). The configured DHCP DUID should
           conform to the specification in RFC 3315[2], RFC 6355[3]. To configure IAID, see systemd.network(5).

           Example 1. A DUIDType=vendor with a custom value

               DUIDType=vendor
               DUIDRawData=00:00:ab:11:f9:2a:c2:77:29:f9:5c:00

           This specifies a 14 byte DUID, with the type DUID-EN ("00:02"), enterprise number 43793
           ("00:00:ab:11"), and identifier value "f9:2a:c2:77:29:f9:5c:00".


SEE ALSO
       systemd(1), systemd.network(5), systemd-networkd.service(8), machine-id(5),
       sd_id128_get_machine_app_specific(3)


NOTES
        1. RFC 3315
           https://tools.ietf.org/html/rfc3315#section-9

        2. RFC 3315
           http://tools.ietf.org/html/rfc3315#section-9

        3. RFC 6355
           http://tools.ietf.org/html/rfc6355