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authorLennart Poettering <lennart@poettering.net>2015-08-27 17:32:30 +0200
committerLennart Poettering <lennart@poettering.net>2015-08-27 17:34:44 +0200
commitad9437836f5d94b44d40ee702a0455a637c30322 (patch)
tree646b125a9d5cf153333c34208101986fccb54d15
parent539f2a73815136cb614e401fbf7807f1ff871d24 (diff)
man: document the new DHCP settings added in the past commits
-rw-r--r--man/systemd.network.xml117
1 files changed, 108 insertions, 9 deletions
diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index e8a164d22d..ded2c0ceff 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -1,4 +1,4 @@
-<?xml version='1.0'?> <!--*-nxml-*-->
+<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
@@ -223,7 +223,7 @@
<varlistentry>
<term><varname>DHCP=</varname></term>
<listitem>
- <para>Enables DHCPv4 and/or DHCPv6 support. Accepts
+ <para>Enables DHCPv4 and/or DHCPv6 client support. Accepts
<literal>yes</literal>, <literal>no</literal>,
<literal>ipv4</literal>, or <literal>ipv6</literal>.</para>
@@ -235,9 +235,10 @@
<varlistentry>
<term><varname>DHCPServer=</varname></term>
<listitem>
- <para>A boolean. Enables a basic DHCPv4 server on the
- device. Mostly useful for handing out leases to container
- instances.</para>
+ <para>A boolean. Enables DHCPv4 server support. Defaults
+ to <literal>no</literal>. Further settings for the DHCP
+ server may be set in the <literal>[DHCPServer]</literal>
+ section described below.</para>
</listitem>
</varlistentry>
<varlistentry>
@@ -541,7 +542,9 @@
<refsect1>
<title>[DHCP] Section Options</title>
- <para>The <literal>[DHCP]</literal> section accepts the following keys:</para>
+ <para>The <literal>[DHCP]</literal> section configures the
+ DHCPv4 and DHCP6 client, if it is enabled with the
+ <varname>DHCP=</varname> setting described above:</para>
<variablelist class='network-directives'>
<varlistentry>
@@ -552,7 +555,8 @@
any statically configured ones.</para>
<para>This corresponds to the <option>nameserver</option>
- option in <citerefentry project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+ option in <citerefentry
+ project='man-pages'><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
</listitem>
</varlistentry>
<varlistentry>
@@ -582,7 +586,7 @@
<term><varname>UseHostname=</varname></term>
<listitem>
<para>When true (the default), the hostname received from
- the DHCP server will be used as the transient hostname.
+ the DHCP server will be set as the transient hostname of the system
</para>
</listitem>
</varlistentry>
@@ -615,6 +619,15 @@
table with metric of 1024.</para>
</listitem>
</varlistentry>
+
+ <varlistentry>
+ <term><varname>UseTimezone=</varname></term>
+
+ <listitem><para>When true, the timezone received from the
+ DHCP server will be set as as timezone of the local
+ system. Defaults to <literal>no</literal>.</para></listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>CriticalConnection=</varname></term>
<listitem>
@@ -658,11 +671,97 @@
DHCP server.</para>
</listitem>
</varlistentry>
- </variablelist>
+ </variablelist>
</refsect1>
<refsect1>
+ <title>[DHCPServer] Section Options</title>
+ <para>The <literal>[DHCPServer]</literal> section contains
+ settings for the DHCP server, if enabled via the
+ <varname>DHCPServer=</varname> option described above:</para>
+
+ <variablelist class='network-directives'>
+
+ <varlistentry>
+ <term><varname>DefaultLeaseTimeSec=</varname></term>
+ <term><varname>MaxLeaseTimeSec=</varname></term>
+
+ <listitem><para>Control the default and maximum DHCP lease
+ time to pass to clients. These settings take time values in seconds or
+ another common time unit, depending on the suffix. The default
+ lease time is used for clients that did not ask for a specific
+ lease time. If a client asks for a lease time longer than the
+ maximum lease time it is automatically shortened to the
+ specified time. The default lease time defaults to 1h, the
+ maximum lease time to 12h. Shorter lease times are beneficial
+ if the configuration data in DHCP leases changes frequently
+ and clients shall learn the new settings with shorter
+ latencies. Longer lease times reduce the generated DHCP
+ network traffic.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>EmitDNS=</varname></term>
+ <term><varname>DNS=</varname></term>
+
+ <listitem><para>Configures whether the DHCP leases handed out
+ to clients shall contain DNS server information. The
+ <varname>EmitDNS=</varname> setting takes a boolean argument
+ and defaults to <literal>yes</literal>. The DNS servers to
+ pass to clients may be configured with the
+ <varname>DNS=</varname> option, which takes a list of IPv4
+ addresses. If the <varname>EmitDNS=</varname> option is
+ enabled but no servers configured the servers are
+ automatically propagated from an "uplink" interface that has
+ appropriate servers set. The "uplink" interface is determined
+ by the default route of the system with the highest
+ priority. Note that this information is acquired at the time
+ the lease is handed out, and does not take uplink interfaces
+ into account that acquire DNS or NTP server information at a
+ later point. DNS server propagation does not take
+ <filename>/etc/resolv.conf</filename> into account. Also, note
+ that the leases are not refreshed if uplink network
+ configuration changes. To ensure clients regularly acquire the
+ most current uplink DNS server information it is thus
+ advisable to shorten the DHCP lease time via
+ <varname>MaxLeaseTimeSec=</varname> described
+ above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>EmitNTP=</varname></term>
+ <term><varname>NTP=</varname></term>
+
+ <listitem><para>Similar to the <varname>EmitDNS=</varname> and
+ <varname>DNS=</varname> settings described above these
+ settings configure whether and what NTP server information
+ shall be emitted as part of the DHCP lease. The same syntax,
+ propagation semantics and defaults apply as for
+ <varname>EmitDNS=</varname> and
+ <varname>DNS=</varname>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>EmitTimezone=</varname></term>
+ <term><varname>Timezone=</varname></term>
+
+ <listitem><para>Configures whether the DHCP leases handed out
+ to clients shall contain timezone information. The
+ <varname>EmitTimezone=</varname> setting takes a boolean
+ argument and defaults to <literal>yes</literal>. The
+ <varname>Timezone=</varname> setting takes a timezone string
+ (such as <literal>Europe/Berlin</literal> or
+ <literal>UTC</literal>) to pass to clients. If no explicit
+ timezone is set the system timezone of the local host is
+ propagated, as determined by the
+ <filename>/etc/localtime</filename> symlink.</para></listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
<title>[Bridge] Section Options</title>
<para>The <literal>[Bridge]</literal> section accepts the
following keys.</para>