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/. The main configuration file is read
29 before any of the configuration directories, and has the lowest
30 precedence; entries in a file in any configuration directory override
31 entries in the single configuration file. Files in the *.conf.d/
32 configuration subdirectories are sorted by their filename in
33 lexicographic order, regardless of in which of the subdirectories they
34 reside. When multiple files specify the same option, for options which
35 accept just a single value, the entry in the file with the
36 lexicographically latest name takes precedence. For options which
37 accept a list of values, entries are collected as they occur in files
38 sorted lexicographically.
39 Files in /etc/ are reserved for the local administrator, who may use
41 this logic to override the configuration files installed by vendor
42 packages. It is recommended to prefix all filenames in those
43 subdirectories with a two-digit number and a dash, to simplify the
44 ordering of the files.
45 To disable a configuration file supplied by the vendor, the recommended
47 way is to place a symlink to /dev/null in the configuration directory
48 in /etc/, with the same filename as the vendor configuration file.
49
51 The following options are available in the "[Network]" section:
52 SpeedMeter=
54 Takes a boolean. If set to yes, then systemd-networkd measures the
55 traffic of each interface, and networkctl status INTERFACE shows
56 the measured speed. Defaults to no.
57 SpeedMeterIntervalSec=
59 Specifies the time interval to calculate the traffic speed of each
60 interface. If SpeedMeter=no, the value is ignored. Defaults to
61 10sec.
62
64 This section configures the DHCP Unique Identifier (DUID) value used by
65 DHCP protocol. DHCPv6 client protocol sends the DHCP Unique Identifier
66 and the interface Identity Association Identifier (IAID) to a DHCP
67 server when acquiring a dynamic IPv6 address. DHCPv4 client protocol
68 sends IAID and DUID to the DHCP server when acquiring a dynamic IPv4
69 address if ClientIdentifier=duid. IAID and DUID allows a DHCP server to
70 uniquely identify the machine and the interface requesting a DHCP IP.
71 To configure IAID and ClientIdentifier, see systemd.network(5).
72 The following options are understood:
74 DUIDType=
76 Specifies how the DUID should be generated. See RFC 3315[1] for a
77 description of all the options.
78 The following values are understood:
80 vendor
82 If "DUIDType=vendor", then the DUID value will be generated
83 using "43793" as the vendor identifier (systemd) and hashed
84 contents of machine-id(5). This is the default if DUIDType= is
85 not specified.
86 uuid
88 If "DUIDType=uuid", and DUIDRawData= is not set, then the
89 product UUID is used as a DUID value. If a system does not have
90 valid product UUID, then an application-specific machine-id(5)
91 is used as a DUID value. About the application-specific machine
92 ID, see sd_id128_get_machine_app_specific(3).
93 link-layer-time[:TIME], link-layer
95 If "link-layer-time" or "link-layer" is specified, then the MAC
96 address of the interface is used as a DUID value. The value
97 "link-layer-time" can take additional time value after a colon,
98 e.g. "link-layer-time:2018-01-23 12:34:56 UTC". The default
99 time value is "2000-01-01 00:00:00 UTC".
100 In all cases, DUIDRawData= can be used to override the actual DUID
102 value that is used.
103 DUIDRawData=
105 Specifies the DHCP DUID value as a single newline-terminated,
106 hexadecimal string, with each byte separated by ":". The DUID that
107 is sent is composed of the DUID type specified by DUIDType= and the
108 value configured here.
109 The DUID value specified here overrides the DUID that systemd-
111 networkd.service(8) generates from the machine ID. To configure
112 DUID per-network, see systemd.network(5). The configured DHCP DUID
113 should conform to the specification in RFC 3315[2], RFC 6355[3]. To
114 configure IAID, see systemd.network(5).
115 Example 1. A DUIDType=vendor with a custom value
117 DUIDType=vendor
119 DUIDRawData=00:00:ab:11:f9:2a:c2:77:29:f9:5c:00
120 This specifies a 14 byte DUID, with the type DUID-EN ("00:02"),
122 enterprise number 43793 ("00:00:ab:11"), and identifier value
123 "f9:2a:c2:77:29:f9:5c:00".
124
126 systemd(1), systemd.network(5), systemd-networkd.service(8), machine-
127 id(5), sd_id128_get_machine_app_specific(3)
128
130 1. RFC 3315
131 https://tools.ietf.org/html/rfc3315#section-9
132 2. RFC 3315
134 http://tools.ietf.org/html/rfc3315#section-9
135 3. RFC 6355
137 http://tools.ietf.org/html/rfc6355
138systemd 245 NETWORKD.CONF(5)