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174 lines
6.5 KiB
HTML
174 lines
6.5 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<!--
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- Copyright (C) 2000-2020 Internet Systems Consortium, Inc. ("ISC")
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-
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- This Source Code Form is subject to the terms of the Mozilla Public
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- License, v. 2.0. If a copy of the MPL was not distributed with this
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- file, You can obtain one at http://mozilla.org/MPL/2.0/.
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<html lang="en">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
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<title>filter-aaaa.so</title>
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<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
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<link rel="home" href="Bv9ARM.html" title="BIND 9 Administrator Reference Manual">
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<link rel="up" href="Bv9ARM.ch12.html" title="Manual pages">
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<link rel="prev" href="man.dnstap-read.html" title="dnstap-read">
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<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
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<div class="navheader">
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<table width="100%" summary="Navigation header">
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<tr><th colspan="3" align="center"><span class="application">filter-aaaa.so</span></th></tr>
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<tr>
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<td width="20%" align="left">
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<a accesskey="p" href="man.dnstap-read.html">Prev</a> </td>
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<th width="60%" align="center">Manual pages</th>
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<td width="20%" align="right"> <a accesskey="n" href="man.host.html">Next</a>
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</td>
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</tr>
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</table>
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<hr>
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</div>
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<div class="refentry">
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<a name="man.filter-aaaa"></a><div class="titlepage"></div>
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<div class="refnamediv">
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<h2>Name</h2>
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<p>
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<span class="application">filter-aaaa.so</span>
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— filter AAAA in DNS responses when A is present
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</p>
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</div>
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<div class="refsynopsisdiv">
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<h2>Synopsis</h2>
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<div class="cmdsynopsis"><p>
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<code class="command">plugin query "filter-aaaa.so"</code>
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[<em class="replaceable"><code>{ parameters }</code></em>];
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</p></div>
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</div>
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<div class="refsection">
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<a name="id-1.13.19.7"></a><h2>DESCRIPTION</h2>
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<p>
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<span class="command"><strong>filter-aaaa.so</strong></span> is a query plugin module for
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<span class="command"><strong>named</strong></span>, enabling <span class="command"><strong>named</strong></span>
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to omit some IPv6 addresses when responding to clients.
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</p>
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<p>
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Until BIND 9.12, this feature was implemented natively in
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<span class="command"><strong>named</strong></span> and enabled with the
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<span class="command"><strong>filter-aaaa</strong></span> ACL and the
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<span class="command"><strong>filter-aaaa-on-v4</strong></span> and
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<span class="command"><strong>filter-aaaa-on-v6</strong></span> options. These options are
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now deprecated in <code class="filename">named.conf</code>, but can be
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passed as parameters to the <span class="command"><strong>filter-aaaa.so</strong></span>
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plugin, for example:
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</p>
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<pre class="programlisting">
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plugin query "/usr/local/lib/filter-aaaa.so" {
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filter-aaaa-on-v4 yes;
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filter-aaaa-on-v6 yes;
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filter-aaaa { 192.0.2.1; 2001:db8:2::1; };
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};
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</pre>
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<p>
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This module is intended to aid transition from IPv4 to IPv6 by
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withholding IPv6 addresses from DNS clients which are not connected
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to the IPv6 Internet, when the name being looked up has an IPv4
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address available. Use of this module is not recommended unless
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absolutely necessary.
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</p>
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<p>
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Note: This mechanism can erroneously cause other servers not to
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give AAAA records to their clients. If a recursing server with
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both IPv6 and IPv4 network connections queries an authoritative
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server using this mechanism via IPv4, it will be denied AAAA
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records even if its client is using IPv6.
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</p>
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</div>
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<div class="refsection">
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<a name="id-1.13.19.8"></a><h2>OPTIONS</h2>
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<div class="variablelist"><dl class="variablelist">
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<dt><span class="term"><span class="command"><strong>filter-aaaa</strong></span></span></dt>
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<dd>
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<p>
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Specifies a list of client addresses for which AAAA
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filtering is to be applied. The default is
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<strong class="userinput"><code>any</code></strong>.
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</p>
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</dd>
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<dt><span class="term"><span class="command"><strong>filter-aaaa-on-v4</strong></span></span></dt>
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<dd>
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<p>
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If set to <strong class="userinput"><code>yes</code></strong>, the DNS client is
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at an IPv4 address, in <span class="command"><strong>filter-aaaa</strong></span>,
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and if the response does not include DNSSEC signatures,
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then all AAAA records are deleted from the response.
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This filtering applies to all responses and not only
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authoritative responses.
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</p>
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<p>
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If set to <strong class="userinput"><code>break-dnssec</code></strong>,
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then AAAA records are deleted even when DNSSEC is
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enabled. As suggested by the name, this causes the
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response to fail to verify, because the DNSSEC protocol is
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designed to detect deletions.
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</p>
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<p>
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This mechanism can erroneously cause other servers not to
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give AAAA records to their clients. A recursing server with
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both IPv6 and IPv4 network connections that queries an
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authoritative server using this mechanism via IPv4 will be
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denied AAAA records even if its client is using IPv6.
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</p>
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</dd>
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<dt><span class="term"><span class="command"><strong>filter-aaaa-on-v6</strong></span></span></dt>
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<dd>
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<p>
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Identical to <span class="command"><strong>filter-aaaa-on-v4</strong></span>,
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except it filters AAAA responses to queries from IPv6
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clients instead of IPv4 clients. To filter all
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responses, set both options to <strong class="userinput"><code>yes</code></strong>.
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</p>
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</dd>
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</dl></div>
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</div>
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<div class="refsection">
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<a name="id-1.13.19.9"></a><h2>SEE ALSO</h2>
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<p>
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<em class="citetitle">BIND 9 Administrator Reference Manual</em>.
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</p>
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</div>
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</div>
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<div class="navfooter">
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<hr>
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<table width="100%" summary="Navigation footer">
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<tr>
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<td width="40%" align="left">
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<a accesskey="p" href="man.dnstap-read.html">Prev</a> </td>
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<td width="20%" align="center"><a accesskey="u" href="Bv9ARM.ch12.html">Up</a></td>
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<td width="40%" align="right"> <a accesskey="n" href="man.host.html">Next</a>
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</td>
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</tr>
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<tr>
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<td width="40%" align="left" valign="top">
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<span class="application">dnstap-read</span> </td>
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<td width="20%" align="center"><a accesskey="h" href="Bv9ARM.html">Home</a></td>
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<td width="40%" align="right" valign="top"> host</td>
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</tr>
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</table>
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</div>
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<p xmlns:db="http://docbook.org/ns/docbook" style="text-align: center;">BIND 9.15.8 (Development Release)</p>
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</body>
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</html>
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