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 defined during compilation, so a
21 configuration file is only needed when it is necessary to deviate from
22 those defaults. By default, the configuration file in /etc/systemd/
23 contains commented out entries showing the defaults as a guide to the
24 administrator. This file can be edited to create local overrides.
25 When packages need to customize the configuration, they can install
27 configuration snippets in /usr/lib/systemd/*.conf.d/ or
28 /usr/local/lib/systemd/*.conf.d/. Files in /etc/ are reserved for the
29 local administrator, who may use this logic to override the
30 configuration files installed by vendor packages. The main
31 configuration file is read before any of the configuration directories,
32 and has the lowest precedence; entries in a file in any configuration
33 directory override entries in the single configuration file. Files in
34 the *.conf.d/ configuration subdirectories are sorted by their filename
35 in lexicographic order, regardless of which of the subdirectories they
36 reside in. When multiple files specify the same option, for options
37 which accept just a single value, the entry in the file with the
38 lexicographically latest name takes precedence. For options which
39 accept a list of values, entries are collected as they occur in files
40 sorted lexicographically. It is recommended to prefix all filenames in
41 those subdirectories with a two-digit number and a dash, to simplify
42 the ordering of the files.
43 To disable a configuration file supplied by the vendor, the recommended
45 way is to place a symlink to /dev/null in the configuration directory
46 in /etc/, with the same filename as the vendor configuration file.
47
49 The following options are available in the "[Network]" section:
50 SpeedMeter=
52 Takes a boolean. If set to yes, then systemd-networkd measures the
53 traffic of each interface, and networkctl status INTERFACE shows
54 the measured speed. Defaults to no.
55 SpeedMeterIntervalSec=
57 Specifies the time interval to calculate the traffic speed of each
58 interface. If SpeedMeter=no, the value is ignored. Defaults to
59 10sec.
60
62 This section configures the DHCP Unique Identifier (DUID) value used by
63 DHCP protocol. DHCPv6 client protocol sends the DHCP Unique Identifier
64 and the interface Identity Association Identifier (IAID) to a DHCP
65 server when acquiring a dynamic IPv6 address. DHCPv4 client protocol
66 sends IAID and DUID to the DHCP server when acquiring a dynamic IPv4
67 address if ClientIdentifier=duid. IAID and DUID allows a DHCP server to
68 uniquely identify the machine and the interface requesting a DHCP IP.
69 To configure IAID and ClientIdentifier, see systemd.network(5).
70 The following options are understood:
72 DUIDType=
74 Specifies how the DUID should be generated. See RFC 3315[1] for a
75 description of all the options.
76 The following values are understood:
78 vendor
80 If "DUIDType=vendor", then the DUID value will be generated
81 using "43793" as the vendor identifier (systemd) and hashed
82 contents of machine-id(5). This is the default if DUIDType= is
83 not specified.
84 uuid
86 If "DUIDType=uuid", and DUIDRawData= is not set, then the
87 product UUID is used as a DUID value. If a system does not have
88 valid product UUID, then an application-specific machine-id(5)
89 is used as a DUID value. About the application-specific machine
90 ID, see sd_id128_get_machine_app_specific(3).
91 link-layer-time[:TIME], link-layer
93 If "link-layer-time" or "link-layer" is specified, then the MAC
94 address of the interface is used as a DUID value. The value
95 "link-layer-time" can take additional time value after a colon,
96 e.g. "link-layer-time:2018-01-23 12:34:56 UTC". The default
97 time value is "2000-01-01 00:00:00 UTC".
98 In all cases, DUIDRawData= can be used to override the actual DUID
100 value that is used.
101 DUIDRawData=
103 Specifies the DHCP DUID value as a single newline-terminated,
104 hexadecimal string, with each byte separated by ":". The DUID that
105 is sent is composed of the DUID type specified by DUIDType= and the
106 value configured here.
107 The DUID value specified here overrides the DUID that systemd-
109 networkd.service(8) generates from the machine ID. To configure
110 DUID per-network, see systemd.network(5). The configured DHCP DUID
111 should conform to the specification in RFC 3315[2], RFC 6355[3]. To
112 configure IAID, see systemd.network(5).
113 Example 1. A DUIDType=vendor with a custom value
115 DUIDType=vendor
117 DUIDRawData=00:00:ab:11:f9:2a:c2:77:29:f9:5c:00
118 This specifies a 14 byte DUID, with the type DUID-EN ("00:02"),
120 enterprise number 43793 ("00:00:ab:11"), and identifier value
121 "f9:2a:c2:77:29:f9:5c:00".
122
124 systemd(1), systemd.network(5), systemd-networkd.service(8), machine-
125 id(5), sd_id128_get_machine_app_specific(3)
126
128 1. RFC 3315
129 https://tools.ietf.org/html/rfc3315#section-9
130 2. RFC 3315
132 http://tools.ietf.org/html/rfc3315#section-9
133 3. RFC 6355
135 http://tools.ietf.org/html/rfc6355
136systemd 243 NETWORKD.CONF(5)