1NETPLUGD(8)               BSD System Manager's Manual              NETPLUGD(8)
2

NAME

4     netplugd — network cable hotplug management daemon
5

SYNOPSIS

7     netplugd [-FP] [-c config_file] [-i interface_pattern] [-p pid_file]
8

DESCRIPTION

10     netplugd is a daemon that responds to network link events from the Linux
11     kernel, such as a network interface losing or acquiring a carrier signal.
12
13     When an Ethernet-style network interface on a host is plugged into a pow‐
14     ered-up switch, hub, or other host, the two use a carrier signal to
15     establish that the link is alive.  The Linux kernel makes this informa‐
16     tion available through its netlink(7) interface.
17
18     The netplugd daemon listens for carrier detection and loss messages from
19     the kernel's netlink(7) subsystem.  When a carrier signal is detected on
20     an interface, it runs a script to bring the interface up.  When carrier
21     is lost, netplugd runs a script to bring the interface down.  netplugd
22     does not define any policies for how to manage interfaces; it leaves that
23     to a script, /etc/netplug.d/netplug, which is described in FILES below.
24
25     You tell netplugd which interfaces it should manage by giving it a list
26     of shell-style glob patterns, which it matches against using the
27     fnmatch(3) function.  For example, a pattern of eth[13] will tell
28     netplugd to only manage eth1 and eth3, if those interfaces exist.  If the
29     interfaces are not known to the kernel at the time you start netplugd,
30     perhaps because they are unplugged PCMCIA network interfaces or devices
31     whose drivers have not yet been installed, netplugd will start to manage
32     them as soon as they are plugged in or their drivers are available.
33

OPTIONS

35     -F      Run in the foreground; do not detach and run as a daemon.  Mes‐
36             sages are logged to stdout or stderr, instead of using the
37             syslog(3) mechanism.  This option is useful mainly for debugging
38             your configuration.
39
40     -P      Prevent autoprobing for interfaces.  The netplugd daemon normally
41             probes for all possible interface names that might match the pat‐
42             terns you tell it to manage.  This is necessary in order to get
43             network driver modules (the default with almost all Linux distri‐
44             butions) loaded and set up, so that they can provide link status
45             notifications to the netplugd daemon.  Autoprobing should always
46             be safe, and doesn't take long.  Disable it with caution.
47
48     -c config_file
49             Specify the name of a file from which to read patterns that
50             describe the interfaces to manage.  You can provide this option
51             multiple times to read from more than one file.  If you do not
52             provide this option at all, netplugd will attempt to read from a
53             default config file.  If you do not want netplugd to try to read
54             from any real config files, you can specify /dev/null as a config
55             file.
56
57     -i interface_pattern
58             Specify a pattern that will be used to match interface names that
59             netplugd should manage.  You can provide this option multiple
60             times to specify multiple patterns.
61
62     -p pid_file
63             Write the daemon's process ID to the file pid_file.  If you tell
64             netplugd to run in the foreground, this option is ignored.
65

FILES

67     /etc/netplug.d/netplugd.conf
68             Default config file to read, if none is specified on the command
69             line.  The config file format is one pattern per line, with white
70             space, empty lines, and comments starting with a # character
71             ignored.  Patterns are standard shell-style glob patterns, e.g.
72             "eth[0-9]".
73
74     /etc/netplug.d/netplug
75             The "policy" program (typically a shell script) that netplugd
76             uses to probe for interfaces, and to bring them up or down in
77             response to network link events.  This program is called with the
78             name of the interface as its first argument, and one of the fol‐
79             lowing options:
80
81             in      A cable was plugged in, or carrier came up.  The command
82                     should bring the interface up.  The command is run asyn‐
83                     chronously, and it should exit with status 0 on success.
84
85             out     A cable was plugged out, or carrier went down.  The com‐
86                     mand should bring the interface down.  The command is run
87                     asynchronously, and it should exit with status 0 on suc‐
88                     cess.
89
90             probe   The command should load and initialise the driver for
91                     this interface, if possible, and bring the interface into
92                     the "up" state, so that it can generate netlink(7)
93                     events.  The command is run synchronously; it must exit
94                     with status code 0 if it succeeds, otherwise with a non-
95                     zero exit code or signal.
96

AUTHOR

98     netplugd was written by Bryan O'Sullivan <bos@serpentine.com>.
99
101     Copyright 2003 PathScale, Inc.  Copyright 2003, 2004, 2005 Bryan O'Sulli‐
102     van
103
104     netplugd is free software; you can redistribute it and/or modify it under
105     the terms of the GNU General Public License, version 2, as published by
106     the Free Software Foundation.  You are forbidden from redistributing or
107     modifying it under the terms of any other license, including other ver‐
108     sions of the GNU General Public License.
109
110     netplugd is distributed in the hope that it will be useful, but WITHOUT
111     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
112     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
113     more details.
114

SEE ALSO

116     cardmgr(5), hotplug(8), ip(8), netlink(7)
117
118Linux 2.6                       August 26, 2003                      Linux 2.6
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