man/nss-resolve.xml

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   8   Copyright 2011 Lennart Poettering
   9   Copyright 2013 Tom Gundersen
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  24
  25 <refentry id="nss-resolve" conditional='ENABLE_RESOLVED'>
  26
  27   <refentryinfo>
  28     <title>nss-resolve</title>
  29     <productname>systemd</productname>
  30
  31     <authorgroup>
  32       <author>
  33         <contrib>Developer</contrib>
  34         <firstname>Lennart</firstname>
  35         <surname>Poettering</surname>
  36         <email>lennart@poettering.net</email>
  37       </author>
  38     </authorgroup>
  39   </refentryinfo>
  40
  41   <refmeta>
  42     <refentrytitle>nss-resolve</refentrytitle>
  43     <manvolnum>8</manvolnum>
  44   </refmeta>
  45
  46   <refnamediv>
  47     <refname>nss-resolve</refname>
  48     <refname>libnss_resolve.so.2</refname>
  49     <refpurpose>Provide hostname resolution via <filename>systemd-resolved.service</filename></refpurpose>
  50   </refnamediv>
  51
  52   <refsynopsisdiv>
  53     <para><filename>libnss_resolve.so.2</filename></para>
  54   </refsynopsisdiv>
  55
  56   <refsect1>
  57     <title>Description</title>
  58
  59     <para><command>nss-resolve</command> is a plug-in module for the GNU Name Service Switch (NSS) functionality of the
  60     GNU C Library (<command>glibc</command>) enabling it to resolve host names via the
  61     <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry> local network
  62     name resolution service. It replaces the <command>nss-dns</command> plug-in module that traditionally resolves
  63     hostnames via DNS.</para>
  64
  65     <para>To activate the NSS module, add <literal>resolve</literal> to the line starting with
  66     <literal>hosts:</literal> in <filename>/etc/nsswitch.conf</filename>.</para>
  67
  68     <para>It is recommended to place <literal>resolve</literal> early in <filename>/etc/nsswitch.conf</filename>'
  69     <literal>hosts:</literal> line (but after the <literal>files</literal> or <literal>mymachines</literal> entries),
  70     replacing the <literal>dns</literal> entry if it exists, to ensure DNS queries are always routed via
  71     <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
  72
  73     <para>Note that <command>nss-resolve</command> will chain-load <command>nss-dns</command> if
  74     <filename>systemd-resolved.service</filename> is not running, ensuring that basic DNS resolution continues to work
  75     if the service is down.</para>
  76   </refsect1>
  77
  78   <refsect1>
  79     <title>Example</title>
  80
  81     <para>Here is an example <filename>/etc/nsswitch.conf</filename> file that enables <command>nss-resolve</command>
  82     correctly:</para>
  83
  84 <programlisting>passwd:         compat mymachines
  85 group:          compat mymachines
  86 shadow:         compat
  87
  88 hosts:          files mymachines <command>resolve</command> myhostname
  89 networks:       files
  90
  91 protocols:      db files
  92 services:       db files
  93 ethers:         db files
  94 rpc:            db files
  95
  96 netgroup:       nis</programlisting>
  97
  98   </refsect1>
  99
 100   <refsect1>
 101     <title>See Also</title>
 102     <para>
 103       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 104       <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 105       <citerefentry><refentrytitle>nss-mymachines</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 106       <citerefentry><refentrytitle>nss-myhostname</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 107       <citerefentry project='man-pages'><refentrytitle>nsswitch.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 108     </para>
 109   </refsect1>
 110
 111 </refentry>