<para>The configuration files contain a list of
variable assignments, separated by newlines. Empty
lines and lines whose first non-whitespace character
- is # or ; are ignored.</para>
-
- <para>Note that both / and . are accepted as label
- separators within sysctl variable
- names. <literal>kernel.domainname=foo</literal> and
- <literal>kernel/domainname=foo</literal> hence are
- entirely equivalent.</para>
+ 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
+ <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>Each configuration file shall be named in the
style of <filename><replaceable>program</replaceable>.conf</filename>.
administrator, who may use this logic to override the
configuration files installed by vendor packages. All
configuration files are sorted by their filename in
- alphabetical order, regardless in which of the
- directories they reside. If multiple files specify the
+ lexicographic order, regardless of which of the
+ directories they reside in. If multiple files specify the
same variable name, the entry in the file with the
- alphabetically latest name will be applied. It is
+ lexicographically latest name will be applied. It is
recommended to prefix all filenames with a two-digit
number and a dash, to simplify the ordering of the
files.</para>
<filename>/dev/null</filename> in
<filename>/etc/sysctl.d/</filename> bearing the
same filename.</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>
</refsect1>
<refsect1>