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 plugin module for the
  60     GNU Name Service Switch (NSS) functionality of the GNU C Library
  61     (<command>glibc</command>) enabling it to resolve host names via
  62     the
  63     <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  64     local network name resolution service.</para>
  65
  66     <para>To activate the NSS module, <literal>resolve</literal>
  67     has to be added to the line starting with
  68     <literal>hosts:</literal> in
  69     <filename>/etc/nsswitch.conf</filename>.</para>
  70
  71     <para>It is recommended to place <literal>resolve</literal> early
  72     in the <filename>nsswitch.conf</filename> line (but after the
  73     <literal>files</literal> entry), replacing the
  74     <literal>dns</literal> entry if it exists, to ensure DNS queries
  75     are always routed via
  76     <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
  77   </refsect1>
  78
  79   <refsect1>
  80     <title>Example</title>
  81
  82     <para>Here is an example <filename>/etc/nsswitch.conf</filename>
  83     file that enables <command>resolve</command> correctly:</para>
  84
  85 <programlisting>passwd:         compat mymachines
  86 group:          compat mymachines
  87 shadow:         compat
  88
  89 hosts:          files <command>resolve</command> mymachines myhostname
  90 networks:       files
  91
  92 protocols:      db files
  93 services:       db files
  94 ethers:         db files
  95 rpc:            db files
  96
  97 netgroup:       nis</programlisting>
  98
  99     <para>Note that <command>nss-resolve</command> will chain-load
 100     <command>nss-dns</command> if
 101     <filename>systemd-resolved.service</filename> is not running,
 102     ensuring that basic DNS resolution continues to work if the
 103     service is down.</para>
 104
 105   </refsect1>
 106
 107   <refsect1>
 108     <title>See Also</title>
 109     <para>
 110       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 111       <citerefentry><refentrytitle>systemd-resolved</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 112       <citerefentry><refentrytitle>nss-mymachines</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 113       <citerefentry><refentrytitle>nss-myhostname</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 114       <citerefentry project='man-pages'><refentrytitle>nsswitch.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 115     </para>
 116   </refsect1>
 117
 118 </refentry>