Reworded sections of "Reasons to run a name server" and changed
definition of "Origin" in DNS section. Reviewed by: murray
This commit is contained in:
Chern Lee
parent
65edfaeafc
commit
8821260cc9
Notes:
svn2git
2020-12-08 03:00:23 +00:00
svn path=/head/; revision=10213
1 changed files with 49 additions and 64 deletions
|
|
@ -1,7 +1,7 @@
|
||||||
<!--
|
<!--
|
||||||
The FreeBSD Documentation Project
|
The FreeBSD Documentation Project
|
||||||
|
|
||||||
$FreeBSD: doc/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.sgml,v 1.68 2001/08/06 20:25:01 chern Exp $
|
$FreeBSD: doc/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.sgml,v 1.69 2001/08/06 21:25:27 chern Exp $
|
||||||
-->
|
-->
|
||||||
|
|
||||||
<chapter id="advanced-networking">
|
<chapter id="advanced-networking">
|
||||||
|
|
@ -3023,7 +3023,8 @@ dhcp_flags=""</programlisting>
|
||||||
|
|
||||||
<row>
|
<row>
|
||||||
<entry>origin</entry>
|
<entry>origin</entry>
|
||||||
<entry>refers to the point of start for the particular zone</entry>
|
<entry>refers to the domain covered for the particular zone
|
||||||
|
file</entry>
|
||||||
</row>
|
</row>
|
||||||
|
|
||||||
<row>
|
<row>
|
||||||
|
|
@ -3106,69 +3107,53 @@ dhcp_flags=""</programlisting>
|
||||||
|
|
||||||
<sect2>
|
<sect2>
|
||||||
<title>Reasons to run a name server</title>
|
<title>Reasons to run a name server</title>
|
||||||
|
|
||||||
|
<para>Name servers usually come in two forms: an authoritative
|
||||||
|
name server, and a caching nameserver.</para>
|
||||||
|
|
||||||
|
<para>An authoritative name server is needed when:</para>
|
||||||
|
|
||||||
<itemizedlist>
|
<itemizedlist>
|
||||||
<listitem>
|
<listitem>
|
||||||
<para>
|
<para>one wants to serve DNS information to the
|
||||||
A machine is needed to host DNS information to the world
|
world, replying authoritatively to queries.</para>
|
||||||
</para>
|
|
||||||
<itemizedlist>
|
|
||||||
<listitem>
|
|
||||||
<para>An authoritative nameserver replies exclusively
|
|
||||||
to requests.
|
|
||||||
</para>
|
|
||||||
</listitem>
|
</listitem>
|
||||||
<listitem>
|
<listitem>
|
||||||
<para>For example, <hostid>foobardomain.org</hostid> is
|
<para>a domain, such as <hostid>foobardomain.org</hostid>, is
|
||||||
registered and IP addresses need to be assigned to hostnames
|
registered and IP addresses need to be assigned to hostnames
|
||||||
under this domain.
|
under it.</para>
|
||||||
</para>
|
|
||||||
</listitem>
|
</listitem>
|
||||||
<listitem>
|
<listitem>
|
||||||
<para>A slave nameserver, which replies to queries for a
|
<para>an IP address block requires reverse DNS entries (IP to
|
||||||
domain when the primary is down or inaccessible.
|
hostname).</para>
|
||||||
</para>
|
|
||||||
</listitem>
|
</listitem>
|
||||||
<listitem>
|
<listitem>
|
||||||
<para>The above two can also be done with reverse DNS (IP
|
<para>a backup name server, called a slave, must reply to queries
|
||||||
to hostname entries)
|
when the primary is down or inaccessible.</para>
|
||||||
</para>
|
|
||||||
</listitem>
|
</listitem>
|
||||||
</itemizedlist>
|
</itemizedlist>
|
||||||
</listitem>
|
|
||||||
<listitem>
|
<para>A caching name server is needed when:</para>
|
||||||
<para>
|
|
||||||
A machine is needed to act as a local cache of DNS information
|
|
||||||
</para>
|
|
||||||
<itemizedlist>
|
<itemizedlist>
|
||||||
<listitem>
|
<listitem>
|
||||||
<para>DNS traffic has been measured to be about 5% or more
|
<para>a local DNS server may cache and respond more quickly
|
||||||
of the total Internet traffic.
|
then querying an outside name server.</para>
|
||||||
</para>
|
|
||||||
</listitem>
|
</listitem>
|
||||||
<listitem>
|
<listitem>
|
||||||
<para>A local DNS server may have some added benefit by
|
<para>a reduction in overall network traffic is desired. (DNS
|
||||||
providing a local cache of DNS information.
|
traffic has been measured to account for 5% or more of total
|
||||||
</para>
|
Internet traffic)</para>
|
||||||
</listitem>
|
|
||||||
<listitem>
|
|
||||||
<para>
|
|
||||||
For example, when one queries for
|
|
||||||
<hostid>www.freebsd.org</hostid>,
|
|
||||||
the resolver usually queries the uplink ISP's name
|
|
||||||
server, and retrieves the query.
|
|
||||||
</para>
|
|
||||||
</listitem>
|
|
||||||
<listitem>
|
|
||||||
<para>
|
|
||||||
With a local, caching DNS server, the query only has to
|
|
||||||
be made once to the outside world. Every additional
|
|
||||||
query will not have to look to the outside of the local
|
|
||||||
network, since the information is cached.
|
|
||||||
</para>
|
|
||||||
</listitem>
|
|
||||||
</itemizedlist>
|
|
||||||
</listitem>
|
</listitem>
|
||||||
</itemizedlist>
|
</itemizedlist>
|
||||||
|
|
||||||
|
<para>When one queries for <hostid>www.freebsd.org</hostid>, the
|
||||||
|
resolver usually queries the uplink ISP's name server, and retrieves
|
||||||
|
the reply. With a local, caching DNS server, the query only has to
|
||||||
|
be made once to the outside world by the caching DNS server. Every
|
||||||
|
additional query will not have to look to the outside of the local
|
||||||
|
network, since the information is cached locally.</para>
|
||||||
|
|
||||||
</sect2>
|
</sect2>
|
||||||
|
|
||||||
<sect2>
|
<sect2>
|
||||||
|
|
|
||||||
Loading…
Reference in a new issue