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 - Copyright (C) 2015-2017  Internet Systems Consortium, Inc. ("ISC")
 -
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<!-- Converted by db4-upgrade version 1.0 -->
<informaltable xmlns:db="http://docbook.org/ns/docbook" version="5.0" colsep="0" rowsep="0">
  <tgroup cols="2" colsep="0" rowsep="0" tgroupstyle="4Level-table">
    <colspec colname="1" colnum="1" colsep="0" colwidth="1.150in"/>
    <colspec colname="2" colnum="2" colsep="0" colwidth="3.350in"/>
    <tbody>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>client</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Processing of client requests.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>cname</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Logs nameservers that are skipped due to them being
	    a CNAME rather than A / AAAA records.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>config</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Configuration file parsing and processing.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>database</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Messages relating to the databases used
	    internally by the name server to store zone and cache
	    data.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>default</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    The default category defines the logging
	    options for those categories where no specific
	    configuration has been
	    defined.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>delegation-only</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Delegation only.  Logs queries that have been
	    forced to NXDOMAIN as the result of a
	    delegation-only zone or a
	    <command>delegation-only</command> in a
	    forward, hint or stub zone declaration.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>dispatch</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Dispatching of incoming packets to the
	    server modules where they are to be processed.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>dnssec</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    DNSSEC and TSIG protocol processing.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>dnstap</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    The "dnstap" DNS traffic capture system.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>edns-disabled</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Log queries that have been forced to use plain
	    DNS due to timeouts.  This is often due to
	    the remote servers not being RFC 1034 compliant
	    (not always returning FORMERR or similar to
	    EDNS queries and other extensions to the DNS
	    when they are not understood).  In other words, this is
	    targeted at servers that fail to respond to
	    DNS queries that they don't understand.
	  </para>
	  <para>
	    Note: the log message can also be due to
	    packet loss.  Before reporting servers for
	    non-RFC 1034 compliance they should be re-tested
	    to determine the nature of the non-compliance.
	    This testing should prevent or reduce the
	    number of false-positive reports.
	  </para>
	  <para>
	    Note: eventually <command>named</command> will have to stop
	    treating such timeouts as due to RFC 1034 non
	    compliance and start treating it as plain
	    packet loss.  Falsely classifying packet
	    loss as due to RFC 1034 non compliance impacts
	    on DNSSEC validation which requires EDNS for
	    the DNSSEC records to be returned.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>general</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    The catch-all. Many things still aren't
	    classified into categories, and they all end up here.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>lame-servers</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Lame servers.  These are misconfigurations
	    in remote servers, discovered by BIND 9 when trying to
	    query those servers during resolution.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>network</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Network operations.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>notify</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    The NOTIFY protocol.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>queries</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Specify where queries should be logged to.
	  </para>
	  <para>
	    At startup, specifying the category <command>queries</command> will also
	    enable query logging unless <command>querylog</command> option has been
	    specified.
	  </para>

	  <para>
	    The query log entry first reports a client object
	    identifier in @0x&lt;hexadecimal-number&gt;
	    format. Next, it reports the client's IP
	    address and port number, and the query name,
	    class and type.  Next, it reports whether the
	    Recursion Desired flag was set (+ if set, -
	    if not set), whether the query was signed (S),
	    whether EDNS was in use along with the EDNS version
	    number (E(#)), whether TCP was used (T), whether
	    DO (DNSSEC Ok) was set (D), whether CD (Checking
	    Disabled) was set (C), whether a valid DNS Server
	    COOKIE was received (V), and whether a DNS
	    COOKIE option without a valid Server COOKIE was
	    present (K).  After this the destination
	    address the query was sent to is reported.
	    Finally, if any CLIENT-SUBNET option
	    was present in the client query, it is
	    included in square brackets in the format
	    [ECS <replaceable>address/source/scope</replaceable>].
	  </para>

	  <para>
	    <computeroutput>client 127.0.0.1#62536 (www.example.com): query: www.example.com IN AAAA +SE</computeroutput>
	  </para>
	  <para>
	    <computeroutput>client ::1#62537 (www.example.net): query: www.example.net IN AAAA -SE</computeroutput>
	  </para>
	  <para>
	    (The first part of this log message, showing the
	    client address/port number and query name, is
	    repeated in all subsequent log messages related
	    to the same query.)
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>query-errors</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Information about queries that resulted in some
	    failure.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>rate-limit</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    The start, periodic, and final notices of the
	    rate limiting of a stream of responses are logged at
	    <command>info</command> severity in this category.
	    These messages include a hash value of the domain name
	    of the response and the name itself,
	    except when there is insufficient memory to record
	    the name for the final notice
	    The final notice is normally delayed until about one
	    minute after rate limit stops.
	    A lack of memory can hurry the final notice,
	    in which case it starts with an asterisk (*).
	    Various internal events are logged at debug 1 level
	    and higher.
	  </para>
	  <para>
	    Rate limiting of individual requests
	    is logged in the <command>query-errors</command> category.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>resolver</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    DNS resolution, such as the recursive
	    lookups performed on behalf of clients by a caching name
	    server.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>rpz</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Information about errors in response policy zone files,
	    rewritten responses, and at the highest
	    <command>debug</command> levels, mere rewriting
	    attempts.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>security</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Approval and denial of requests.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>spill</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Logs queries that have been terminated, either by dropping
	    or responding with SERVFAIL, as a result of a fetchlimit
	    quota being exceeded.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>trust-anchor-telemetry</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Logs trust-anchor-telemetry requests received by named.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>unmatched</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Messages that <command>named</command> was unable to determine the
	    class of or for which there was no matching <command>view</command>.
	    A one line summary is also logged to the <command>client</command> category.
	    This category is best sent to a file or stderr, by
	    default it is sent to
	    the <command>null</command> channel.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>update</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Dynamic updates.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>update-security</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Approval and denial of update requests.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>xfer-in</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Zone transfers the server is receiving.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>xfer-out</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Zone transfers the server is sending.
	  </para>
	</entry>
      </row>
      <row rowsep="0">
	<entry colname="1">
	  <para><command>zoneload</command></para>
	</entry>
	<entry colname="2">
	  <para>
	    Loading of zones and creation of automatic empty zones.
	  </para>
	</entry>
      </row>
    </tbody>
  </tgroup>
</informaltable>
