<?xml version="1.0"?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
- "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
-<!-- SPDX-License-Identifier: LGPL-2.1+ -->
+ "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
+<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
<refentry id="sysctl.d"
xmlns:xi="http://www.w3.org/2001/XInclude">
</refnamediv>
<refsynopsisdiv>
- <para><filename>/etc/sysctl.d/*.conf</filename></para>
- <para><filename>/run/sysctl.d/*.conf</filename></para>
- <para><filename>/usr/lib/sysctl.d/*.conf</filename></para>
+ <para><simplelist>
+ <member><filename>/etc/sysctl.d/*.conf</filename></member>
+ <member><filename>/run/sysctl.d/*.conf</filename></member>
+ <member><filename>/usr/lib/sysctl.d/*.conf</filename></member>
+ </simplelist></para>
+
+ <programlisting>key.name.under.proc.sys = some value
+key/name/under/proc/sys = some value
+key/middle.part.with.dots/foo = 123
+key.middle/part/with/dots.foo = 123
+-key.that.will.not.fail = value
+key.pattern.*.with.glob = whatever
+-key.pattern.excluded.with.glob
+key.pattern.overridden.with.glob = custom
+</programlisting>
</refsynopsisdiv>
<refsect1>
first non-whitespace character is <literal>#</literal> or
<literal>;</literal> are ignored.</para>
- <para>Note that either <literal>/</literal> or
- <literal>.</literal> may be used as separators within sysctl
- variable names. If the first separator is a slash, remaining
- slashes and dots are left intact. If the first separator is a dot,
- dots and slashes are interchanged.
- <literal>kernel.domainname=foo</literal> and
- <literal>kernel/domainname=foo</literal> are equivalent and will
- cause <literal>foo</literal> to be written to
+ <para>Note that either <literal>/</literal> or <literal>.</literal> may be used as separators within
+ sysctl variable names. If the first separator is a slash, remaining slashes and dots are left intact. If
+ the first separator is a dot, dots and slashes are interchanged.
+ <literal>kernel.domainname=foo</literal> and <literal>kernel/domainname=foo</literal> are equivalent and
+ will cause <literal>foo</literal> to be written to
<filename>/proc/sys/kernel/domainname</filename>. Either
<literal>net.ipv4.conf.enp3s0/200.forwarding</literal> or
- <literal>net/ipv4/conf/enp3s0.200/forwarding</literal> may be used
- to refer to
- <filename>/proc/sys/net/ipv4/conf/enp3s0.200/forwarding</filename>.
- </para>
-
- <para>Any access permission errors and attempts to write variables not defined on the local system are
- logged, but do not cause the service to fail. Moreover, if a variable assignment is prefixed with a
- single <literal>-</literal> character, failure to set the variable will be logged, but will not cause the
- service to fail. All other errors when setting variables cause the service to return failure at the end
- (other variables are still processed).</para>
-
- <para>The settings configured with <filename>sysctl.d</filename>
- files will be applied early on boot. The network
- interface-specific options will also be applied individually for
- each network interface as it shows up in the system. (More
- specifically, <filename>net.ipv4.conf.*</filename>,
- <filename>net.ipv6.conf.*</filename>,
- <filename>net.ipv4.neigh.*</filename> and
+ <literal>net/ipv4/conf/enp3s0.200/forwarding</literal> may be used to refer to
+ <filename>/proc/sys/net/ipv4/conf/enp3s0.200/forwarding</filename>. A glob
+ <citerefentry project='man-pages'><refentrytitle>glob</refentrytitle><manvolnum>7</manvolnum></citerefentry> pattern may be
+ used to write the same value to all matching keys. Keys for which an explicit pattern exists will be
+ excluded from any glob matching. In addition, a key may be explicitly excluded from being set by any
+ matching glob patterns by specifying the key name prefixed with a <literal>-</literal> character and not
+ followed by <literal>=</literal>, see SYNOPSIS.</para>
+
+ <para>Any access permission errors and attempts to write variables not present on the local system are
+ logged at debug level and do not cause the service to fail. Other types of errors when setting variables
+ are logged with higher priority and cause the service to return failure at the end (after processing
+ other variables). As an exception, if a variable assignment is prefixed with a single
+ <literal>-</literal> character, failure to set the variable for any reason will be logged at debug level
+ and will not cause the service to fail.</para>
+
+ <para>The settings configured with <filename>sysctl.d</filename> files will be applied early on boot. The
+ network interface-specific options will also be applied individually for each network interface as it
+ shows up in the system. (More specifically, <filename>net.ipv4.conf.*</filename>,
+ <filename>net.ipv6.conf.*</filename>, <filename>net.ipv4.neigh.*</filename> and
<filename>net.ipv6.neigh.*</filename>).</para>
<para>Many sysctl parameters only become available when certain
(starting with kernel 3.18), so simply not loading the module is
sufficient to avoid filtering.</para>
</example>
+
+ <example>
+ <title>Set network routing properties for all interfaces</title>
+ <para><filename>/etc/sysctl.d/20-rp_filter.conf</filename>:</para>
+
+ <programlisting>net.ipv4.conf.default.rp_filter = 2
+net.ipv4.conf.*.rp_filter = 2
+-net.ipv4.conf.all.rp_filter
+net.ipv4.conf.hub0.rp_filter = 1
+</programlisting>
+
+ <para>The <option>rp_filter</option> key will be set to "2" for all interfaces, except "hub0". We set
+ <filename>net.ipv4.conf.default.rp_filter</filename> first, so any interfaces which are added
+ <emphasis>later</emphasis> will get this value (this also covers any interfaces detected while we're
+ running). The glob matches any interfaces which were detected <emphasis>earlier</emphasis>. The glob
+ will also match <filename>net.ipv4.conf.all.rp_filter</filename>, which we don't want to set at all, so
+ it is explicitly excluded. And "hub0" is excluded from the glob because it has an explicit setting.
+ </para>
+ </example>
+
</refsect1>
<refsect1>
<title>See Also</title>
- <para>
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd-sysctl.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry project='man-pages'><refentrytitle>sysctl.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry project='man-pages'><refentrytitle>modprobe</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- </para>
+ <para><simplelist type="inline">
+ <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
+ <member><citerefentry><refentrytitle>systemd-sysctl.service</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
+ <member><citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
+ <member><citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
+ <member><citerefentry project='man-pages'><refentrytitle>sysctl.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
+ <member><citerefentry project='man-pages'><refentrytitle>modprobe</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
+ </simplelist></para>
</refsect1>
</refentry>
projects / thirdparty / systemd.git / blobdiff