systemd networkd.conf 5 networkd.conf networkd.conf.d Global Network configuration files /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 These configuration files control global network parameters. 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. 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. 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. 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. 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. 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 for more details about the sysctl options. Defaults to unset and the sysctl options will not be changed. If an interface is configured with a .network file that enables IPMasquerade= for IPv4 (that is, ipv4 or both), this setting is implied unless explicitly specified. See IPMasquerade= in systemd.network5 for more details. 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 for more details about the sysctl options. Defaults to unset and the sysctl options will not be changed. If an interface is configured with a .network file that enables IPMasquerade= for IPv6 (that is, ipv6 or both), this setting is implied unless explicitly specified. See IPMasquerade= in systemd.network5 for more details. 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.network5. Defaults to no. 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.network5. Defaults to no. 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.network5. Takes a boolean, or the special value route. When unspecified, the value specified in the [Network] section in networkd.conf5, which defaults to no, will be used. An [IPv6AddressLabel] section accepts the following keys. Specify multiple [IPv6AddressLabel] sections to configure multiple address labels. IPv6 address labels are used for address selection. See RFC 3484. Precedence is managed by userspace, and only the label itself is stored in the kernel. Label= The label for the prefix, an unsigned integer in the range 0…4294967294. 0xffffffff is reserved. This setting is mandatory. Prefix= IPv6 prefix is an address with a prefix length, separated by a slash / character. This setting is mandatory. 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.network5. The following options are understood: DUIDType= Specifies how the DUID should be generated. See RFC 3315 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-id5. 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-id5 is used as a DUID value. About the application-specific machine ID, see sd_id128_get_machine_app_specific3. 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.service8 generates from the machine ID. To configure DUID per-network, see systemd.network5. The configured DHCP DUID should conform to the specification in RFC 3315, RFC 6355. To configure IAID, see systemd.network5 . 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. UseDomains= Same as the one in the [IPv6AcceptRA] section, but applied for DHCPv4 protocol. 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.network5. The following options are understood: DUIDType= DUIDRawData= As in the [DHCPv4] section. UseDomains= As in the [DHCPv4] section. 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. systemd1 systemd.network5 systemd-networkd.service8 machine-id5 sd_id128_get_machine_app_specific3