Eric Luce
f293a69bcd
files written out to something with more easily understood file names (Bv9ARM.ch##.html) and remove the old HTML files. We were not able to have XML just drop in replace them due to not being able to use an XML id tag that begins with a number. Hence "ch01" instead of "1."
227 lines
3.9 KiB
HTML
227 lines
3.9 KiB
HTML
<HTML
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><HEAD
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><TITLE
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>The BIND 9 Lightweight Resolver</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.54"><LINK
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REL="HOME"
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HREF="Bv9ARM.html"><LINK
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REL="PREVIOUS"
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TITLE="Advanced Concepts"
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HREF="Bv9ARM.ch04.html"><LINK
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REL="NEXT"
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TITLE="BIND 9 Configuration Reference"
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HREF="Bv9ARM.ch06.html"></HEAD
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><BODY
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CLASS="chapter"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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></TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="Bv9ARM.ch04.html"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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></TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="Bv9ARM.ch06.html"
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>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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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="chapter"
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><H1
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><A
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NAME="ch05"
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>Chapter 5. The <SPAN
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CLASS="acronym"
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>BIND</SPAN
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> 9 Lightweight Resolver</A
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></H1
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><DIV
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CLASS="TOC"
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><DL
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><DT
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><B
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>Table of Contents</B
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></DT
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><DT
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>5.1. <A
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HREF="Bv9ARM.ch05.html#AEN989"
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>The Lightweight Resolver Library</A
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></DT
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><DT
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>5.2. <A
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HREF="Bv9ARM.ch05.html#AEN995"
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>Running a Resolver Daemon</A
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></DT
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></DL
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></DIV
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><DIV
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CLASS="sect1"
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><H1
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CLASS="sect1"
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><A
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NAME="AEN989"
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>5.1. The Lightweight Resolver Library</A
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></H1
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><P
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>Traditionally applications have been linked with a stub resolver
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library that sends recursive DNS queries to a local caching name
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server.</P
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><P
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>IPv6 introduces new complexity into the resolution process,
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such as following A6 chains and DNAME records, and simultaneous
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lookup of IPv4 and IPv6 addresses. These are hard or impossible
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to implement in a traditional stub resolver.</P
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><P
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>Instead, <SPAN
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CLASS="acronym"
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>BIND</SPAN
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> 9 provides resolution services to local clients
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using a combination of a lightweight resolver library and a resolver
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daemon process running on the local host. These communicate using
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a simple UDP-based protocol, the "lightweight resolver protocol"
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that is distinct from and simpler than the full DNS protocol.</P
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></DIV
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><DIV
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CLASS="sect1"
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><H1
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CLASS="sect1"
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><A
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NAME="AEN995"
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>5.2. Running a Resolver Daemon</A
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></H1
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><P
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>To use the lightweight resolver interface, the system must
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run the resolver daemon <B
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CLASS="command"
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>lwresd</B
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>.</P
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><P
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>Applications using the lightweight resolver library will make
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UDP requests to the IPv4 loopback address (127.0.0.1) on port 921.
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The daemon will try to find the answer to the questions "what are the
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addresses for host <SPAN
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CLASS="systemitem"
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>foo.example.com</SPAN
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>?" and "what are
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the names for IPv4 address 204.152.184.79?"</P
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><P
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>The daemon currently only looks in the DNS, but in the future
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it may use other sources such as <TT
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CLASS="literal"
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>/etc/hosts</TT
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>,
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NIS, etc.</P
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><P
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>The <B
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CLASS="command"
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>lwresd</B
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> daemon is essentially a stripped-down,
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caching-only name server that answers requests using the lightweight
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resolver protocol rather than the DNS protocol. Because it needs
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to run on each host, it is designed to require no or minimal configuration.
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It uses the name servers listed on <B
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CLASS="command"
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>nameserver</B
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> lines
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in <TT
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CLASS="filename"
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>/etc/resolv.conf</TT
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> as forwarders, but is also
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capable of doing the resolution autonomously if none are specified.</P
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></DIV
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="Bv9ARM.ch04.html"
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>Prev</A
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></TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="Bv9ARM.html"
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>Home</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><A
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HREF="Bv9ARM.ch06.html"
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>Next</A
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></TD
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Advanced Concepts</TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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> </TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><SPAN
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CLASS="acronym"
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>BIND</SPAN
|
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> 9 Configuration Reference</TD
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></TR
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></TABLE
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></DIV
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></BODY
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></HTML
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> |