Ubuntu Manpage: networkd.conf, networkd.conf.d - Global Network configuration files

Provided by: systemd_256.5-2ubuntu3.1_amd64

NAME

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

SYNOPSIS

           /etc/systemd/networkd.conf
           /run/systemd/networkd.conf
           /usr/local/lib/systemd/networkd.conf
           /usr/lib/systemd/networkd.conf
           /etc/systemd/networkd.conf.d/*.conf
           /run/systemd/networkd.conf.d/*.conf
           /usr/local/lib/systemd/networkd.conf.d/*.conf
           /usr/lib/systemd/networkd.conf.d/*.conf

DESCRIPTION

       These configuration files control global network parameters.

CONFIGURATION DIRECTORIES AND PRECEDENCE

The default configuration is set during compilation, so configuration is only needed when
it is necessary to deviate from those defaults. The main configuration file is loaded from
one of the listed directories in order of priority, only the first file found is used:
/etc/systemd/, /run/systemd/, /usr/local/lib/systemd/ [1], /usr/lib/systemd/. The vendor
version of the file contains commented out entries showing the defaults as a guide to the
administrator. Local overrides can also be created by creating drop-ins, as described
below. The main configuration file can also be edited for this purpose (or a copy in /etc/
if it's shipped under /usr/), however using drop-ins for local configuration is
recommended over modifications to the main configuration file.

In addition to the main configuration file, drop-in configuration snippets are read from
/usr/lib/systemd/*.conf.d/, /usr/local/lib/systemd/*.conf.d/, and /etc/systemd/*.conf.d/.
Those drop-ins have higher precedence and override the main 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 sorted last takes precedence, and for options which accept a list of values, entries
are collected as they occur in the sorted files.

When packages need to customize the configuration, they can install drop-ins under /usr/.
Files in /etc/ are reserved for the local administrator, who may use this logic to
override the configuration files installed by vendor packages. Drop-ins have to be used to
override package drop-ins, since the main configuration file has lower precedence. It is
recommended to prefix all filenames in those subdirectories with a two-digit number and a
dash, to simplify the ordering. This also defines a concept of drop-in priorities to allow
OS vendors to ship drop-ins within a specific range lower than the range used by users.
This should lower the risk of package drop-ins overriding accidentally drop-ins defined by
users. It is recommended to use the range 10-40 for drop-ins in /usr/ and the range 60-90
for drop-ins in /etc/ and /run/, to make sure that local and transient drop-ins take
priority over drop-ins shipped by the OS vendor.

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.

Added in version 244.

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

Added in version 244.

ManageForeignRoutingPolicyRules=
A boolean. When true, systemd-networkd will remove rules that are not configured in
.network files (except for rules with protocol "kernel"). When false, it will not
remove any foreign rules, keeping them even if they are not configured in a .network
file. Defaults to yes.

Added in version 249.

ManageForeignRoutes=
A boolean. When true, systemd-networkd will remove routes that are not configured in
.network files (except for routes with protocol "kernel", "dhcp" when
KeepConfiguration= is true or "dhcp", and "static" when KeepConfiguration= is true or
"static"). When false, it will not remove any foreign routes, keeping them even if
they are not configured in a .network file. Defaults to yes.

Added in version 246.

ManageForeignNextHops=
A boolean. When true, systemd-networkd will remove nexthops that are not configured in
.network files (except for routes with protocol "kernel"). When false, it will not
remove any foreign nexthops, keeping them even if they are not configured in a
.network file. Defaults to yes.

Added in version 256.

RouteTable=
Defines the route table name. Takes a whitespace-separated list of the pairs of route
table name and number. The route table name and number in each pair are separated with
a colon, i.e., "name:number". The route table name must not be "default", "main", or
"local", as these route table names are predefined with route table number 253, 254,
and 255, respectively. The route table number must be an integer in the range
1...4294967295, except for predefined numbers 253, 254, and 255. This setting can be
specified multiple times. If an empty string is specified, then the list specified
earlier are cleared. Defaults to unset.

Added in version 248.

IPv4Forwarding=
Configures IPv4 packet forwarding for the system. Takes a boolean value. This controls
the net.ipv4.conf.default.forwarding and net.ipv4.conf.all.forwardingsysctl options.
See IP Sysctl[2] for more details about the sysctl options. Defaults to unset and the
sysctl options will not be changed.

Added in version 256.

IPv6Forwarding=
Configures IPv6 packet forwarding for the system. Takes a boolean value. This controls
the net.ipv6.conf.default.forwarding and net.ipv6.conf.all.forwarding sysctl options.
See IP Sysctl[2] for more details about the sysctl options. Defaults to unset and the
sysctl options will not be changed.

Added in version 256.

IPv6PrivacyExtensions=
Specifies the default value for per-network IPv6PrivacyExtensions=. Takes a boolean or
the special values "prefer-public" and "kernel". See for details in
systemd.network(5). Defaults to "no".

Added in version 254.

UseDomains=
Specifies the network- and protocol-independent default value for the same settings in
[IPv6AcceptRA], [DHCPv4], and [DHCPv6] sections below. Takes a boolean, or the special
value route. See the same setting in systemd.network(5). Defaults to "no".

Added in version 256.

[IPV6ACCEPTRA] SECTION OPTIONS

       This section configures the default setting of the Neighbor Discovery. The following
       options are available in the [IPv6AcceptRA] section:

       UseDomains=
           Specifies the network-independent default value for the same setting in the
           [IPv6AcceptRA] section in systemd.network(5). Takes a boolean, or the special value
           route. When unspecified, the value specified in the [Network] section in
           networkd.conf(5), which defaults to "no", will be used.

           Added in version 256.

[DHCPV4] SECTION OPTIONS

This section configures the DHCP Unique Identifier (DUID) value used by DHCP protocol.
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 address. 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[3] for a description of all
the options.

This takes an integer in the range 0...65535, or one of the following string values:

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.

Added in version 230.

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).

Added in version 230.

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".

Added in version 240.

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

Added in version 230.

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[4], RFC
6355[5]. 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".

Added in version 230.

UseDomains=
Same as the one in the [IPv6AcceptRA] section, but applied for DHCPv4 protocol.

Added in version 256.

[DHCPV6] SECTION OPTIONS

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

       The following options are understood:

       DUIDType=, DUIDRawData=
           As in the [DHCPv4] section.

           Added in version 249.

       UseDomains=
           As in the [DHCPv4] section.

           Added in version 256.

[DHCPSERVER] SECTION OPTIONS

       This section configures the default setting of the DHCP server. The following options are
       available in the [DHCPServer] section:

       UseDomains=
           Same as the one in the [IPv6AcceptRA] section, but applied for DHCPv4 protocol.

           Added in version 256.

NOTES

        1. 💣💥🧨💥💥💣 Please note that those configuration files must be available at all times.
           If /usr/local/ is a separate partition, it may not be available during early boot, and
           must not be used for configuration.

        2. IP Sysctl
           https://docs.kernel.org/networking/ip-sysctl.html

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

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

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

NAME

SYNOPSIS

DESCRIPTION

CONFIGURATION DIRECTORIES AND PRECEDENCE

[NETWORK] SECTION OPTIONS

[IPV6ACCEPTRA] SECTION OPTIONS

[DHCPV4] SECTION OPTIONS

[DHCPV6] SECTION OPTIONS

[DHCPSERVER] SECTION OPTIONS

SEE ALSO

NOTES