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Though most of the complexity was 64 then removed, these are hard or impossible 65 to implement in a traditional stub resolver. 66 </p> 67<p> 68 <acronym class="acronym">BIND</acronym> 9 therefore can also provide resolution 69 services to local clients 70 using a combination of a lightweight resolver library and a resolver 71 daemon process running on the local host. These communicate using 72 a simple UDP-based protocol, the "lightweight resolver protocol" 73 that is distinct from and simpler than the full DNS protocol. 74 </p> 75</div> 76<div class="sect1" lang="en"> 77<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 78<a name="lwresd"></a>Running a Resolver Daemon</h2></div></div></div> 79<p> 80 To use the lightweight resolver interface, the system must 81 run the resolver daemon <span><strong class="command">lwresd</strong></span> or a 82 local 83 name server configured with a <span><strong class="command">lwres</strong></span> 84 statement. 85 </p> 86<p> 87 By default, applications using the lightweight resolver library will 88 make 89 UDP requests to the IPv4 loopback address (127.0.0.1) on port 921. 90 The 91 address can be overridden by <span><strong class="command">lwserver</strong></span> 92 lines in 93 <code class="filename">/etc/resolv.conf</code>. 94 </p> 95<p> 96 The daemon currently only looks in the DNS, but in the future 97 it may use other sources such as <code class="filename">/etc/hosts</code>, 98 NIS, etc. 99 </p> 100<p> 101 The <span><strong class="command">lwresd</strong></span> daemon is essentially a 102 caching-only name server that responds to requests using the 103 lightweight 104 resolver protocol rather than the DNS protocol. Because it needs 105 to run on each host, it is designed to require no or minimal 106 configuration. 107 Unless configured otherwise, it uses the name servers listed on 108 <span><strong class="command">nameserver</strong></span> lines in <code class="filename">/etc/resolv.conf</code> 109 as forwarders, but is also capable of doing the resolution 110 autonomously if 111 none are specified. 112 </p> 113<p> 114 The <span><strong class="command">lwresd</strong></span> daemon may also be 115 configured with a 116 <code class="filename">named.conf</code> style configuration file, 117 in 118 <code class="filename">/etc/lwresd.conf</code> by default. A name 119 server may also 120 be configured to act as a lightweight resolver daemon using the 121 <span><strong class="command">lwres</strong></span> statement in <code class="filename">named.conf</code>. 122 </p> 123</div> 124</div> 125<div class="navfooter"> 126<hr> 127<table width="100%" summary="Navigation footer"> 128<tr> 129<td width="40%" align="left"> 130<a accesskey="p" href="Bv9ARM.ch04.html">Prev</a>�</td> 131<td width="20%" align="center">�</td> 132<td width="40%" align="right">�<a accesskey="n" href="Bv9ARM.ch06.html">Next</a> 133</td> 134</tr> 135<tr> 136<td width="40%" align="left" valign="top">Chapter�4.�Advanced DNS Features�</td> 137<td width="20%" align="center"><a accesskey="h" href="Bv9ARM.html">Home</a></td> 138<td width="40%" align="right" valign="top">�Chapter�6.�<acronym class="acronym">BIND</acronym> 9 Configuration Reference</td> 139</tr> 140</table> 141</div> 142</body> 143</html> 144