1NETWORKD.CONF(5) networkd.conf NETWORKD.CONF(5)
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6 networkd.conf, networkd.conf.d - Global Network configuration files
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9 /etc/systemd/networkd.conf
10 /etc/systemd/networkd.conf.d/*.conf
12 /usr/lib/systemd/networkd.conf.d/*.conf
14
16 These configuration files control global network parameters. Currently
17 the DHCP Unique Identifier (DUID).
18
20 The default configuration is set during compilation, so configuration
21 is only needed when it is necessary to deviate from those defaults.
22 Initially, the main configuration file in /etc/systemd/ contains
23 commented out entries showing the defaults as a guide to the
24 administrator. Local overrides can be created by editing this file or
25 by creating drop-ins, as described below. Using drop-ins for local
26 configuration is recommended over modifications to the main
27 configuration file.
28 In addition to the "main" configuration file, drop-in configuration
30 snippets are read from /usr/lib/systemd/*.conf.d/,
31 /usr/local/lib/systemd/*.conf.d/, and /etc/systemd/*.conf.d/. Those
32 drop-ins have higher precedence and override the main configuration
33 file. Files in the *.conf.d/ configuration subdirectories are sorted by
34 their filename in lexicographic order, regardless of in which of the
35 subdirectories they reside. When multiple files specify the same
36 option, for options which accept just a single value, the entry in the
37 file sorted last takes precedence, and for options which accept a list
38 of values, entries are collected as they occur in the sorted files.
39 When packages need to customize the configuration, they can install
41 drop-ins under /usr/. Files in /etc/ are reserved for the local
42 administrator, who may use this logic to override the configuration
43 files installed by vendor packages. Drop-ins have to be used to
44 override package drop-ins, since the main configuration file has lower
45 precedence. It is recommended to prefix all filenames in those
46 subdirectories with a two-digit number and a dash, to simplify the
47 ordering of the files.
48 To disable a configuration file supplied by the vendor, the recommended
50 way is to place a symlink to /dev/null in the configuration directory
51 in /etc/, with the same filename as the vendor configuration file.
52
54 The following options are available in the [Network] section:
55 SpeedMeter=
57 Takes a boolean. If set to yes, then systemd-networkd measures the
58 traffic of each interface, and networkctl status INTERFACE shows
59 the measured speed. Defaults to no.
60 SpeedMeterIntervalSec=
62 Specifies the time interval to calculate the traffic speed of each
63 interface. If SpeedMeter=no, the value is ignored. Defaults to
64 10sec.
65 ManageForeignRoutingPolicyRules=
67 A boolean. When true, systemd-networkd will remove rules that are
68 not configured in .network files (except for rules with protocol
69 "kernel"). When false, it will not remove any foreign rules,
70 keeping them even if they are not configured in a .network file.
71 Defaults to yes.
72 ManageForeignRoutes=
74 A boolean. When true, systemd-networkd will remove routes that are
75 not configured in .network files (except for routes with protocol
76 "kernel", "dhcp" when KeepConfiguration= is true or "dhcp", and
77 "static" when KeepConfiguration= is true or "static"). When false,
78 it will not remove any foreign routes, keeping them even if they
79 are not configured in a .network file. Defaults to yes.
80 RouteTable=
82 Defines the route table name. Takes a whitespace-separated list of
83 the pairs of route table name and number. The route table name and
84 number in each pair are separated with a colon, i.e.,
85 "name:number". The route table name must not be "default", "main",
86 or "local", as these route table names are predefined with route
87 table number 253, 254, and 255, respectively. The route table
88 number must be an integer in the range 1...4294967295, except for
89 predefined numbers 253, 254, and 255. This setting can be specified
90 multiple times. If an empty string is specified, then the list
91 specified earlier are cleared. Defaults to unset.
92 IPv6PrivacyExtensions=
94 Specifies the default value for per-network IPv6PrivacyExtensions=.
95 Takes a boolean or the special values "prefer-public" and "kernel".
96 See for details in systemd.network(5). Defaults to "no".
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99 This section configures the DHCP Unique Identifier (DUID) value used by
100 DHCP protocol. DHCPv4 client protocol sends IAID and DUID to the DHCP
101 server when acquiring a dynamic IPv4 address if ClientIdentifier=duid.
102 IAID and DUID allows a DHCP server to uniquely identify the machine and
103 the interface requesting a DHCP IP address. To configure IAID and
104 ClientIdentifier, see systemd.network(5).
105 The following options are understood:
107 DUIDType=
109 Specifies how the DUID should be generated. See RFC 3315[1] for a
110 description of all the options.
111 The following values are understood:
113 vendor
115 If "DUIDType=vendor", then the DUID value will be generated
116 using "43793" as the vendor identifier (systemd) and hashed
117 contents of machine-id(5). This is the default if DUIDType= is
118 not specified.
119 uuid
121 If "DUIDType=uuid", and DUIDRawData= is not set, then the
122 product UUID is used as a DUID value. If a system does not have
123 valid product UUID, then an application-specific machine-id(5)
124 is used as a DUID value. About the application-specific machine
125 ID, see sd_id128_get_machine_app_specific(3).
126 link-layer-time[:TIME], link-layer
128 If "link-layer-time" or "link-layer" is specified, then the MAC
129 address of the interface is used as a DUID value. The value
130 "link-layer-time" can take additional time value after a colon,
131 e.g. "link-layer-time:2018-01-23 12:34:56 UTC". The default
132 time value is "2000-01-01 00:00:00 UTC".
133 In all cases, DUIDRawData= can be used to override the actual DUID
135 value that is used.
136 DUIDRawData=
138 Specifies the DHCP DUID value as a single newline-terminated,
139 hexadecimal string, with each byte separated by ":". The DUID that
140 is sent is composed of the DUID type specified by DUIDType= and the
141 value configured here.
142 The DUID value specified here overrides the DUID that systemd-
144 networkd.service(8) generates from the machine ID. To configure
145 DUID per-network, see systemd.network(5). The configured DHCP DUID
146 should conform to the specification in RFC 3315[2], RFC 6355[3]. To
147 configure IAID, see systemd.network(5).
148 Example 1. A DUIDType=vendor with a custom value
150 DUIDType=vendor
152 DUIDRawData=00:00:ab:11:f9:2a:c2:77:29:f9:5c:00
153 This specifies a 14 byte DUID, with the type DUID-EN ("00:02"),
155 enterprise number 43793 ("00:00:ab:11"), and identifier value
156 "f9:2a:c2:77:29:f9:5c:00".
157
159 This section configures the DHCP Unique Identifier (DUID) value used by
160 DHCPv6 protocol. DHCPv6 client protocol sends the DHCP Unique
161 Identifier and the interface Identity Association Identifier (IAID) to
162 a DHCPv6 server when acquiring a dynamic IPv6 address. IAID and DUID
163 allows a DHCPv6 server to uniquely identify the machine and the
164 interface requesting a DHCP IP address. To configure IAID, see
165 systemd.network(5).
166 The following options are understood:
168 DUIDType=, DUIDRawData=
170 As in the [DHCPv4] section.
171
173 systemd(1), systemd.network(5), systemd-networkd.service(8), machine-
174 id(5), sd_id128_get_machine_app_specific(3)
175
177 1. RFC 3315
178 https://tools.ietf.org/html/rfc3315#section-9
179 2. RFC 3315
181 http://tools.ietf.org/html/rfc3315#section-9
182 3. RFC 6355
184 http://tools.ietf.org/html/rfc6355
185systemd 254 NETWORKD.CONF(5)