core: use the correct APIs to determine whether a dual timestamp is initialized

[thirdparty/systemd.git] / man / resolved.conf.xml

diff --git a/man/resolved.conf.xml b/man/resolved.conf.xml
index 3aa9c3acb11f0ea27befb8f5b01d0cd2fcb11e4e..7556c6ff31569d7768343fec44921f447ddf2b23 100644 (file)
--- a/man/resolved.conf.xml
+++ b/man/resolved.conf.xml
@@ -68,6 +68,8 @@
   <refsect1>
     <title>Options</title>
 
+    <para>The following options are available in the <literal>[Resolve]</literal> section:</para>
+
     <variablelist class='network-directives'>
 
       <varlistentry>
@@ -129,8 +131,8 @@
         <listitem><para>Takes a boolean argument or
         <literal>allow-downgrade</literal>. If true all DNS lookups are
         DNSSEC-validated locally (excluding LLMNR and Multicast
-        DNS). If a response for a lookup request is detected invalid
-        this is returned as lookup failure to applications. Note that
+        DNS). If the response to a lookup request is detected to be invalid
+        a lookup failure is returned to applications. Note that
         this mode requires a DNS server that supports DNSSEC. If the
         DNS server does not properly support DNSSEC all validations
         will fail. If set to <literal>allow-downgrade</literal> DNSSEC
@@ -151,7 +153,7 @@
         is built into the resolver, additional trust anchors may be
         defined with
         <citerefentry><refentrytitle>dnssec-trust-anchors.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
-        Trust anchors may change in regular intervals, and old trust
+        Trust anchors may change at regular intervals, and old trust
         anchors may be revoked. In such a case DNSSEC validation is
         not possible until new trust anchors are configured locally or
         the resolver software package is updated with the new root
@@ -200,6 +202,17 @@
         </listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term><varname>Cache=</varname></term>
+        <listitem><para>Takes a boolean argument. If "yes" (the default), resolving a domain name which already got
+        queried earlier will return the previous result as long as it is still valid, and thus does not result in a new
+        network request. Be aware that that turning off caching comes at a performance penalty, which is particularly
+        high when DNSSEC is used.</para>
+
+        <para>Note that caching is turned off implicitly if the configured DNS server is on a host-local IP address
+        (such as 127.0.0.1 or ::1), in order to avoid duplicate local caching.</para></listitem>
+      </varlistentry>
+
     </variablelist>
   </refsect1>