Network Card daemon. Automatic recognition of active/inactive network interfaces.
Now lets see the manual of netplugd service.Manual netplugd:NAME
netplugd - network cable hotplug management daemonSYNOPSIS
netplugd [-FP] [-c config_file] [-i interface_pattern] [-p pid_file]DESCRIPTION
netplugd is a daemon that responds to network link events from the Linux kernel, such as a network interface losing
or acquiring a carrier signal.
When an Ethernet-style network interface on a host is plugged into a powered-up switch, hub, or other host, the two
use a carrier signal to establish that the link is alive. The Linux kernel makes this information available through
its netlink(7) interface.
The netplugd daemon listens for carrier detection and loss messages from the kernel's netlink(7) subsystem. When a
carrier signal is detected on an interface, it runs a script to bring the interface up. When carrier is lost,
netplugd runs a script to bring the interface down. netplugd does not define any policies for how to manage interfaces;
it leaves that to a script, /etc/netplug.d/netplug, which is described in FILES below.
You tell netplugd which interfaces it should manage by giving it a list of shell-style glob patterns, which it
matches against using the fnmatch(3) function. For example, a pattern of eth will tell netplugd to only manage
eth1 and eth3, if those interfaces exist. If the interfaces are not known to the kernel at the time you start
netplugd, perhaps because they are unplugged PCMCIA network interfaces or devices whose drivers have not yet been
installed, netplugd will start to manage them as soon as they are plugged in or their drivers are available.OPTIONS
-F Run in the foreground; do not detach and run as a daemon. Messages are logged to stdout or stderr, instead
of using the syslog(3) mechanism. This option is useful mainly for debugging your configuration.
-P Prevent autoprobing for interfaces. The netplugd daemon normally probes for all possible interface names
that might match the patterns you tell it to manage. This is necessary in order to get network driver modules
(the default with almost all Linux distributions) loaded and set up, so that they can provide link status
notifications to the netplugd daemon. Autoprobing should always be safe, and doesn't take long. Disable
it with caution.
Specify the name of a file from which to read patterns that describe the interfaces to manage. The config
file format is one pattern per line, with white space, empty lines, and comments starting with a # character
ignored. You can provide this option multiple times to read from more than one file. If you do not provide
this option at all, netplugd will attempt to read from a default config file. If you do not want netplugd to
try to read from any real config files, you can specify /dev/null as a config file.
Specify a pattern that will be used to match interface names that netplugd should manage. You can provide
this option multiple times to specify multiple patterns.
Write the daemon's process ID to the file pid_file. If you tell netplugd to run in the foreground, this
option is ignored.FILES
Default config file to read, if none is specified on the command line.
The "policy" program (typically a shell script) that netplugd uses to probe for interfaces, and to bring them
up or down in response to network link events. This program is called with the name of the interface as its
first argument, and one of the following options:
in A cable was plugged in, or carrier came up. The command should bring the interface up. The command
is run asynchronously, and it should exit with status 0 on success.
out A cable was plugged out, or carrier went down. The command should bring the interface down. The
command is run asynchronously, and it should exit with status 0 on success.
probe The command should load and initialise the driver for this interface, if possible, and bring the
interface into the "up" state, so that it can generate netlink(7) events. The command is run synchronously;
it must exit with status code 0 if it succeeds, otherwise with a non-zero exit code or signal.
The init(8) script that starts, stops, and displays status of the netplugd daemon.AUTHOR
netplugd was written by Bryan O'Sullivan <email@example.com>.COPYRIGHT AND LICENSE
Copyright 2003 PathScale, Inc. Copyright 2003, 2004 Bryan O'Sullivan
netplugd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
License, version 2, as published by the Free Software Foundation. You are forbidden from redistributing or modifying
it under the terms of any other license, including other versions of the GNU General Public License.
netplugd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.SEE ALSO
cardmgr(5), hotplug(8), ip(8), netlink(7)