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 <H1 ALIGN="CENTER">Virtual Host examples for common setups</H1>


 <H2>Base configuration</H2>

 <UL>
 <LI><A HREF="#ip">IP-based vhosts only</A>
 <LI><A HREF="#name">Name-based vhosts only</A>
 <LI><A HREF="#mixed">Mixed name-/IP-based vhosts</A>
 <LI><A HREF="#port">Port-based vhosts</A>
 </UL>

 <H2>Additional features</H2>

 <UL>
 <LI><A HREF="#default">Using <CODE>_default_</CODE> vhosts</A>
 <LI><A HREF="#migrate">Migrating a named-based vhost to an IP-based vhost</A>
 <LI><A HREF="#serverpath">Using the <CODE>ServerPath</CODE> directive</A>
 </UL>

 <HR>

 <H3><A NAME="ip">IP-based vhosts only</A></H3>

 <UL>

 <LI><STRONG>Setup 1:</STRONG>
     The server machine has two IP addresses (<SAMP>111.22.33.44</SAMP>
     and <SAMP>111.22.33.55</SAMP>)
     which resolve to the names <SAMP>server.domain.tld</SAMP> and
     <SAMP>www.otherdomain.tld</SAMP> respectively.
     The hostname <SAMP>www.domain.tld</SAMP> is an alias (CNAME)
     for <SAMP>server.domain.tld</SAMP> and will represent the
     main server.
     <P>
     <STRONG>Server configuration:</STRONG>


     <BLOCKQUOTE><PRE>
     ...
     Port 80
     DocumentRoot /www/domain
     ServerName www.domain.tld

     &lt;VirtualHost 111.22.33.55&gt;
     DocumentRoot /www/otherdomain
     ServerName www.otherdomain.tld
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     <SAMP>www.otherdomain.tld</SAMP> can only be reached through the
     address <SAMP>111.22.33.55</SAMP>, while <SAMP>www.domain.tld</SAMP>
     can only be reached through <SAMP>111.22.33.44</SAMP>
     (which represents our main server).
     </BLOCKQUOTE>
     <P>

 <LI><STRONG>Setup 2:</STRONG>
     Same as setup 1, but we don't want to have a dedicated main server.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     Port 80
     ServerName server.domain.tld

     &lt;VirtualHost 111.22.33.44&gt;
     DocumentRoot /www/domain
     ServerName www.domain.tld
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.55&gt;
     DocumentRoot /www/otherdomain
     ServerName www.otherdomain.tld
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     The main server can never catch a request, because all IP addresses
     of our machine are in use for IP-based virtual hosts
     (only <SAMP>localhost</SAMP> requests can hit the main server).
     </BLOCKQUOTE>
     <P>

 <LI><STRONG>Setup 3:</STRONG>
     The server machine has two IP addresses (<SAMP>111.22.33.44</SAMP>
     and <SAMP>111.22.33.55</SAMP>)
     which resolve to the names <SAMP>server.domain.tld</SAMP> and
     <SAMP>www-cache.domain.tld</SAMP> respectively.
     The hostname <SAMP>www.domain.tld</SAMP> is an alias (CNAME)
     for <SAMP>server.domain.tld</SAMP> and will represent the
     main server.
     <SAMP>www-cache.domain.tld</SAMP> will become our proxy-cache
     listening on port 8080, while the web server itself uses the default
     port 80.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     Port 80
     Listen 111.22.33.44:80
     Listen 111.22.33.55:8080
     ServerName server.domain.tld

     &lt;VirtualHost 111.22.33.44:80&gt;
     DocumentRoot /www/domain
     ServerName www.domain.tld
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.55:8080&gt;
     ServerName www-cache.domain.tld
     ...
       &lt;Directory proxy:&gt;
       order deny,allow
       deny from all
       allow from 111.22.33
       &lt;/Directory&gt;
     &lt;/VirtualHost&gt;
     </PRE>
     The main server can never catch a request, because all IP addresses
     (apart from <SAMP>localhost</SAMP>) of our machine are in use for IP-based
     virtual hosts. The web server can only be reached on the first address
     through port 80 and the proxy only on the second address through port 8080.
     </BLOCKQUOTE>
 </UL>
 <HR>

 <H3><A NAME="name">Name-based vhosts only</A></H3>

 <UL>

 <LI><STRONG>Setup 1:</STRONG>
     The server machine has one IP address (<SAMP>111.22.33.44</SAMP>)
     which resolves to the name <SAMP>server.domain.tld</SAMP>.
     There are two aliases (CNAMEs) <SAMP>www.domain.tld</SAMP> and
     <SAMP>www.sub.domain.tld</SAMP> for the address <SAMP>111.22.33.44</SAMP>.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     Port 80
     ServerName server.domain.tld

     NameVirtualHost 111.22.33.44

     &lt;VirtualHost 111.22.33.44&gt;
     DocumentRoot /www/domain
     ServerName www.domain.tld
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.44&gt;
     DocumentRoot /www/subdomain
     ServerName www.sub.domain.tld
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     Apart from <SAMP>localhost</SAMP> there are no unspecified
     addresses/ports, therefore the main server only serves
     <SAMP>localhost</SAMP> requests. Due to the fact
     that <SAMP>www.domain.tld</SAMP> has the highest priority
     it can be seen as the <CITE>default</CITE> or
     <CITE>primary</CITE> server.
     </BLOCKQUOTE>
     <P>

 <LI><STRONG>Setup 2:</STRONG>
     The server machine has two IP addresses (<SAMP>111.22.33.44</SAMP>
     and <SAMP>111.22.33.55</SAMP>)
     which resolve to the names <SAMP>server1.domain.tld</SAMP> and
     <SAMP>server2.domain.tld</SAMP> respectively.
     The alias <SAMP>www.domain.tld</SAMP> should be used for the
     main server which should also catch any unspecified addresses.
     We want to use a virtual host for the alias
     <SAMP>www.otherdomain.tld</SAMP> and one virtual host should
     catch any request to hostnames of the form
     <SAMP>*.sub.domain.tld</SAMP> with <SAMP>www.sub.domain.tld</SAMP>
     as its server name. The address <SAMP>111.22.33.55</SAMP> should be
     used for the virtual hosts.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     Port 80
     ServerName www.domain.tld
     DocumentRoot /www/domain

     NameVirtualHost 111.22.33.55

     &lt;VirtualHost 111.22.33.55&gt;
     DocumentRoot /www/otherdomain
     ServerName www.otherdomain.tld
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.55&gt;
     DocumentRoot /www/subdomain
     ServerName www.sub.domain.tld
     ServerAlias *.sub.domain.tld
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     Any request to an address other than <SAMP>111.22.33.55</SAMP>
     will be served from the main server. A request to
     <SAMP>111.22.33.55</SAMP> with an unknown or no <CODE>Host:</CODE>
     header will be served from <SAMP>www.otherdomain.tld</SAMP>.
     </BLOCKQUOTE>
 </UL>

 <HR>

 <H3><A NAME="mixed">Mixed name-/IP-based vhosts</A></H3>

 <UL>

 <LI><STRONG>Setup:</STRONG>
     The server machine has three IP addresses (<SAMP>111.22.33.44</SAMP>,
     <SAMP>111.22.33.55</SAMP> and <SAMP>111.22.33.66</SAMP>)
     which resolve to the names <SAMP>server.domain.tld</SAMP>,
     <SAMP>www.otherdomain1.tld</SAMP> and <SAMP>www.otherdomain2.tld</SAMP>
     respectively.
     The address <SAMP>111.22.33.44</SAMP> should we used for a couple
     of name-based vhosts and the other addresses for IP-based vhosts.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     Port 80
     ServerName server.domain.tld

     NameVirtualHost 111.22.33.44

     &lt;VirtualHost 111.22.33.44&gt;
     DocumentRoot /www/domain
     ServerName www.domain.tld
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.44&gt;
     DocumentRoot /www/subdomain1
     ServerName www.sub1.domain.tld
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.44&gt;
     DocumentRoot /www/subdomain2
     ServerName www.sub2.domain.tld
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.55&gt;
     DocumentRoot /www/otherdomain1
     ServerName www.otherdomain1.tld
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.66&gt;
     DocumentRoot /www/otherdomain2
     ServerName www.otherdomain2.tld
     ...
     &lt;/VirtualHost&gt;
     </PRE></BLOCKQUOTE>

 </UL>

 <HR>

 <H3><A NAME="port">Port-based vhosts</A></H3>

 <UL>

 <LI><STRONG>Setup:</STRONG>
     The server machine has one IP address (<SAMP>111.22.33.44</SAMP>)
     which resolves to the name <SAMP>www.domain.tld</SAMP>.
     If we don't have the option to get another address or alias
     for our server we can use port-based vhosts if we need
     a virtual host with a different configuration.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     Listen 80
     Listen 8080
     ServerName www.domain.tld
     DocumentRoot /www/domain

     &lt;VirtualHost 111.22.33.44:8080&gt;
     DocumentRoot /www/domain2
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     A request to <SAMP>www.domain.tld</SAMP> on port 80 is served
     from the main server and a request to port 8080 is served from
     the virtual host.
     </BLOCKQUOTE>
 </UL>

 <HR>

 <H3><A NAME="default">Using <CODE>_default_</CODE> vhosts</A></H3>

 <UL>

 <LI><STRONG>Setup 1:</STRONG>
     Catching <EM>every</EM> request to any unspecified IP address and port,
     <EM>i.e.</EM>, an address/port combination that is not used for any other
     virtual host.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     &lt;VirtualHost _default_:*&gt;
     DocumentRoot /www/default
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     Using such a default vhost with a wildcard port effectively
     prevents any request going to the main server.<BR>
     A default vhost never serves a request that was sent to an
     address/port that is used for name-based vhosts. If the request
     contained an unknown or no <CODE>Host:</CODE> header it is
     always served from the primary name-based vhost (the
     vhost for that address/port appearing first in the configuration
     file).<BR>
     You can use
     <A HREF="../mod/mod_alias.html#aliasmatch"><CODE>AliasMatch</CODE></A>
     or
     <A HREF="../mod/mod_rewrite.html#RewriteRule"><CODE>RewriteRule</CODE></A>
     to rewrite any request to a single information page (or script).
     </BLOCKQUOTE>
     <P>

 <LI><STRONG>Setup 2:</STRONG>
     Same as setup 1, but the server listens on several ports and
     we want to use a second <CODE>_default_</CODE> vhost for port 80.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     &lt;VirtualHost _default_:80&gt;
     DocumentRoot /www/default80
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost _default_:*&gt;
     DocumentRoot /www/default
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     The default vhost for port 80 (which <EM>must</EM> appear before
     any default vhost with a wildcard port) catches all requests that
     were sent to an unspecified IP address. The main server is
     never used to serve a request.
     </BLOCKQUOTE>
     <P>

 <LI><STRONG>Setup 3:</STRONG>
     We want to have a default vhost for port 80, but no other default vhosts.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     &lt;VirtualHost _default_:80&gt;
     DocumentRoot /www/default
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     A request to an unspecified address on port 80 is served from the
     default vhost any other request to an unspecified address and port
     is served from the main server.
     </BLOCKQUOTE>

 </UL>

 <HR>

 <H3><A NAME="migrate">Migrating a name-based vhost to an IP-based vhost</A></H3>

 <UL>

 <LI><STRONG>Setup:</STRONG>
     The name-based vhost with the hostname
     <SAMP>www.otherdomain.tld</SAMP> (from our <A HREF="#name">name-based</A>
     example, setup 2) should get its own IP address.
     To avoid problems with name servers or proxies who cached the old
     IP address for the name-based vhost we want to provide both variants
     during a migration phase.<BR>
     The solution is easy, because we can simply add the new IP address
     (<SAMP>111.22.33.66</SAMP>) to the <CODE>VirtualHost</CODE> directive.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     Port 80
     ServerName www.domain.tld
     DocumentRoot /www/domain

     NameVirtualHost 111.22.33.55

     &lt;VirtualHost 111.22.33.55 111.22.33.66&gt;
     DocumentRoot /www/otherdomain
     ServerName www.otherdomain.tld
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.55&gt;
     DocumentRoot /www/subdomain
     ServerName www.sub.domain.tld
     ServerAlias *.sub.domain.tld
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     The vhost can now be accessed through the new address (as an IP-based
     vhost) and through the old address (as a name-based vhost).
     </BLOCKQUOTE>

 </UL>

 <HR>

 <H3><A NAME="serverpath">Using the <CODE>ServerPath</CODE> directive</A></H3>

 <UL>

 <LI><STRONG>Setup:</STRONG>
     We have a server with two name-based vhosts. In order to match the correct
     virtual host a client must send the correct <CODE>Host:</CODE> header.
     Old HTTP/1.0 clients do not send such a header and Apache has no clue
     what vhost the client tried to reach (and serves the request from
     the primary vhost). To provide as much backward compatibility
     as possible we create a primary vhost which returns a single page
     containing links with an URL prefix to the name-based virtual hosts.
     <P>
     <STRONG>Server configuration:</STRONG>

     <BLOCKQUOTE><PRE>
     ...
     NameVirtualHost 111.22.33.44

     &lt;VirtualHost 111.22.33.44&gt;
     # primary vhost
     DocumentRoot /www/subdomain
     RewriteEngine On
     RewriteRule ^/.* /www/subdomain/index.html
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.44&gt;
     DocumentRoot /www/subdomain/sub1
     ServerName www.sub1.domain.tld
     ServerPath /sub1/
     RewriteEngine On
     RewriteRule ^(/sub1/.*) /www/subdomain$1
     ...
     &lt;/VirtualHost&gt;

     &lt;VirtualHost 111.22.33.44&gt;
     DocumentRoot /www/subdomain/sub2
     ServerName www.sub2.domain.tld
     ServerPath /sub2/
     RewriteEngine On
     RewriteRule ^(/sub2/.*) /www/subdomain$1
     ...
     &lt;/VirtualHost&gt;
     </PRE>
     Due to the <A HREF="../mod/core.html#serverpath"><CODE>ServerPath</CODE></A>
     directive a request to the
     URL <SAMP>http://www.sub1.domain.tld/sub1/</SAMP> is <EM>always</EM>
     served from the sub1-vhost. <BR>
     A request to the URL <SAMP>http://www.sub1.domain.tld/</SAMP>
     is only served from the sub1-vhost if the client sent a correct
     <CODE>Host:</CODE> header.
     If no <CODE>Host:</CODE> header is sent the client gets the
     information page from the primary host.<BR>
     Please note that there is one oddity: A request to
     <SAMP>http://www.sub2.domain.tld/sub1/</SAMP> is also served from
     the sub1-vhost if the client sent no <CODE>Host:</CODE> header. <BR>
     The <CODE>RewriteRule</CODE> directives are used to make sure that
     a client which sent a correct <CODE>Host:</CODE> header can use
     both URL variants, <EM>i.e.</EM>, with or without URL prefix.
     </BLOCKQUOTE>

 </UL>

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 </HTML>
	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
	<HTML><HEAD>
	<TITLE>VirtualHost Examples</TITLE>
	</HEAD>

	<!-- Background white, links blue (unvisited), navy (visited), red (active) -->
	<BODY
	BGCOLOR="#FFFFFF"
	TEXT="#000000"
	LINK="#0000FF"
	VLINK="#000080"
	ALINK="#FF0000"
	>
	<!--#include virtual="header.html" -->
	<H1 ALIGN="CENTER">Virtual Host examples for common setups</H1>


	<H2>Base configuration</H2>

	<UL>
	<LI><A HREF="#ip">IP-based vhosts only</A>
	<LI><A HREF="#name">Name-based vhosts only</A>
	<LI><A HREF="#mixed">Mixed name-/IP-based vhosts</A>
	<LI><A HREF="#port">Port-based vhosts</A>
	</UL>

	<H2>Additional features</H2>

	<UL>
	<LI><A HREF="#default">Using <CODE>_default_</CODE> vhosts</A>
	<LI><A HREF="#migrate">Migrating a named-based vhost to an IP-based vhost</A>
	<LI><A HREF="#serverpath">Using the <CODE>ServerPath</CODE> directive</A>
	</UL>

	<HR>

	<H3><A NAME="ip">IP-based vhosts only</A></H3>

	<UL>

	<LI><STRONG>Setup 1:</STRONG>
	The server machine has two IP addresses (<SAMP>111.22.33.44</SAMP>
	and <SAMP>111.22.33.55</SAMP>)
	which resolve to the names <SAMP>server.domain.tld</SAMP> and
	<SAMP>www.otherdomain.tld</SAMP> respectively.
	The hostname <SAMP>www.domain.tld</SAMP> is an alias (CNAME)
	for <SAMP>server.domain.tld</SAMP> and will represent the
	main server.
	<P>
	<STRONG>Server configuration:</STRONG>


	<BLOCKQUOTE><PRE>
	...
	Port 80
	DocumentRoot /www/domain
	ServerName www.domain.tld

	<VirtualHost 111.22.33.55>
	DocumentRoot /www/otherdomain
	ServerName www.otherdomain.tld
	...
	</VirtualHost>
	</PRE>
	<SAMP>www.otherdomain.tld</SAMP> can only be reached through the
	address <SAMP>111.22.33.55</SAMP>, while <SAMP>www.domain.tld</SAMP>
	can only be reached through <SAMP>111.22.33.44</SAMP>
	(which represents our main server).
	</BLOCKQUOTE>
	<P>

	<LI><STRONG>Setup 2:</STRONG>
	Same as setup 1, but we don't want to have a dedicated main server.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	Port 80
	ServerName server.domain.tld

	<VirtualHost 111.22.33.44>
	DocumentRoot /www/domain
	ServerName www.domain.tld
	...
	</VirtualHost>

	<VirtualHost 111.22.33.55>
	DocumentRoot /www/otherdomain
	ServerName www.otherdomain.tld
	...
	</VirtualHost>
	</PRE>
	The main server can never catch a request, because all IP addresses
	of our machine are in use for IP-based virtual hosts
	(only <SAMP>localhost</SAMP> requests can hit the main server).
	</BLOCKQUOTE>
	<P>

	<LI><STRONG>Setup 3:</STRONG>
	The server machine has two IP addresses (<SAMP>111.22.33.44</SAMP>
	and <SAMP>111.22.33.55</SAMP>)
	which resolve to the names <SAMP>server.domain.tld</SAMP> and
	<SAMP>www-cache.domain.tld</SAMP> respectively.
	The hostname <SAMP>www.domain.tld</SAMP> is an alias (CNAME)
	for <SAMP>server.domain.tld</SAMP> and will represent the
	main server.
	<SAMP>www-cache.domain.tld</SAMP> will become our proxy-cache
	listening on port 8080, while the web server itself uses the default
	port 80.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	Port 80
	Listen 111.22.33.44:80
	Listen 111.22.33.55:8080
	ServerName server.domain.tld

	<VirtualHost 111.22.33.44:80>
	DocumentRoot /www/domain
	ServerName www.domain.tld
	...
	</VirtualHost>

	<VirtualHost 111.22.33.55:8080>
	ServerName www-cache.domain.tld
	...
	<Directory proxy:>
	order deny,allow
	deny from all
	allow from 111.22.33
	</Directory>
	</VirtualHost>
	</PRE>
	The main server can never catch a request, because all IP addresses
	(apart from <SAMP>localhost</SAMP>) of our machine are in use for IP-based
	virtual hosts. The web server can only be reached on the first address
	through port 80 and the proxy only on the second address through port 8080.
	</BLOCKQUOTE>
	</UL>
	<HR>

	<H3><A NAME="name">Name-based vhosts only</A></H3>

	<UL>

	<LI><STRONG>Setup 1:</STRONG>
	The server machine has one IP address (<SAMP>111.22.33.44</SAMP>)
	which resolves to the name <SAMP>server.domain.tld</SAMP>.
	There are two aliases (CNAMEs) <SAMP>www.domain.tld</SAMP> and
	<SAMP>www.sub.domain.tld</SAMP> for the address <SAMP>111.22.33.44</SAMP>.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	Port 80
	ServerName server.domain.tld

	NameVirtualHost 111.22.33.44

	<VirtualHost 111.22.33.44>
	DocumentRoot /www/domain
	ServerName www.domain.tld
	...
	</VirtualHost>

	<VirtualHost 111.22.33.44>
	DocumentRoot /www/subdomain
	ServerName www.sub.domain.tld
	...
	</VirtualHost>
	</PRE>
	Apart from <SAMP>localhost</SAMP> there are no unspecified
	addresses/ports, therefore the main server only serves
	<SAMP>localhost</SAMP> requests. Due to the fact
	that <SAMP>www.domain.tld</SAMP> has the highest priority
	it can be seen as the <CITE>default</CITE> or
	<CITE>primary</CITE> server.
	</BLOCKQUOTE>
	<P>

	<LI><STRONG>Setup 2:</STRONG>
	The server machine has two IP addresses (<SAMP>111.22.33.44</SAMP>
	and <SAMP>111.22.33.55</SAMP>)
	which resolve to the names <SAMP>server1.domain.tld</SAMP> and
	<SAMP>server2.domain.tld</SAMP> respectively.
	The alias <SAMP>www.domain.tld</SAMP> should be used for the
	main server which should also catch any unspecified addresses.
	We want to use a virtual host for the alias
	<SAMP>www.otherdomain.tld</SAMP> and one virtual host should
	catch any request to hostnames of the form
	<SAMP>*.sub.domain.tld</SAMP> with <SAMP>www.sub.domain.tld</SAMP>
	as its server name. The address <SAMP>111.22.33.55</SAMP> should be
	used for the virtual hosts.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	Port 80
	ServerName www.domain.tld
	DocumentRoot /www/domain

	NameVirtualHost 111.22.33.55

	<VirtualHost 111.22.33.55>
	DocumentRoot /www/otherdomain
	ServerName www.otherdomain.tld
	...
	</VirtualHost>

	<VirtualHost 111.22.33.55>
	DocumentRoot /www/subdomain
	ServerName www.sub.domain.tld
	ServerAlias *.sub.domain.tld
	...
	</VirtualHost>
	</PRE>
	Any request to an address other than <SAMP>111.22.33.55</SAMP>
	will be served from the main server. A request to
	<SAMP>111.22.33.55</SAMP> with an unknown or no <CODE>Host:</CODE>
	header will be served from <SAMP>www.otherdomain.tld</SAMP>.
	</BLOCKQUOTE>
	</UL>

	<HR>

	<H3><A NAME="mixed">Mixed name-/IP-based vhosts</A></H3>

	<UL>

	<LI><STRONG>Setup:</STRONG>
	The server machine has three IP addresses (<SAMP>111.22.33.44</SAMP>,
	<SAMP>111.22.33.55</SAMP> and <SAMP>111.22.33.66</SAMP>)
	which resolve to the names <SAMP>server.domain.tld</SAMP>,
	<SAMP>www.otherdomain1.tld</SAMP> and <SAMP>www.otherdomain2.tld</SAMP>
	respectively.
	The address <SAMP>111.22.33.44</SAMP> should we used for a couple
	of name-based vhosts and the other addresses for IP-based vhosts.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	Port 80
	ServerName server.domain.tld

	NameVirtualHost 111.22.33.44

	<VirtualHost 111.22.33.44>
	DocumentRoot /www/domain
	ServerName www.domain.tld
	...
	</VirtualHost>

	<VirtualHost 111.22.33.44>
	DocumentRoot /www/subdomain1
	ServerName www.sub1.domain.tld
	...
	</VirtualHost>

	<VirtualHost 111.22.33.44>
	DocumentRoot /www/subdomain2
	ServerName www.sub2.domain.tld
	...
	</VirtualHost>

	<VirtualHost 111.22.33.55>
	DocumentRoot /www/otherdomain1
	ServerName www.otherdomain1.tld
	...
	</VirtualHost>

	<VirtualHost 111.22.33.66>
	DocumentRoot /www/otherdomain2
	ServerName www.otherdomain2.tld
	...
	</VirtualHost>
	</PRE></BLOCKQUOTE>

	</UL>

	<HR>

	<H3><A NAME="port">Port-based vhosts</A></H3>

	<UL>

	<LI><STRONG>Setup:</STRONG>
	The server machine has one IP address (<SAMP>111.22.33.44</SAMP>)
	which resolves to the name <SAMP>www.domain.tld</SAMP>.
	If we don't have the option to get another address or alias
	for our server we can use port-based vhosts if we need
	a virtual host with a different configuration.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	Listen 80
	Listen 8080
	ServerName www.domain.tld
	DocumentRoot /www/domain

	<VirtualHost 111.22.33.44:8080>
	DocumentRoot /www/domain2
	...
	</VirtualHost>
	</PRE>
	A request to <SAMP>www.domain.tld</SAMP> on port 80 is served
	from the main server and a request to port 8080 is served from
	the virtual host.
	</BLOCKQUOTE>
	</UL>

	<HR>

	<H3><A NAME="default">Using <CODE>_default_</CODE> vhosts</A></H3>

	<UL>

	<LI><STRONG>Setup 1:</STRONG>
	Catching <EM>every</EM> request to any unspecified IP address and port,
	<EM>i.e.</EM>, an address/port combination that is not used for any other
	virtual host.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	<VirtualHost _default_:*>
	DocumentRoot /www/default
	...
	</VirtualHost>
	</PRE>
	Using such a default vhost with a wildcard port effectively
	prevents any request going to the main server.<BR>
	A default vhost never serves a request that was sent to an
	address/port that is used for name-based vhosts. If the request
	contained an unknown or no <CODE>Host:</CODE> header it is
	always served from the primary name-based vhost (the
	vhost for that address/port appearing first in the configuration
	file).<BR>
	You can use
	<A HREF="../mod/mod_alias.html#aliasmatch"><CODE>AliasMatch</CODE></A>
	or
	<A HREF="../mod/mod_rewrite.html#RewriteRule"><CODE>RewriteRule</CODE></A>
	to rewrite any request to a single information page (or script).
	</BLOCKQUOTE>
	<P>

	<LI><STRONG>Setup 2:</STRONG>
	Same as setup 1, but the server listens on several ports and
	we want to use a second <CODE>_default_</CODE> vhost for port 80.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	<VirtualHost _default_:80>
	DocumentRoot /www/default80
	...
	</VirtualHost>

	<VirtualHost _default_:*>
	DocumentRoot /www/default
	...
	</VirtualHost>
	</PRE>
	The default vhost for port 80 (which <EM>must</EM> appear before
	any default vhost with a wildcard port) catches all requests that
	were sent to an unspecified IP address. The main server is
	never used to serve a request.
	</BLOCKQUOTE>
	<P>

	<LI><STRONG>Setup 3:</STRONG>
	We want to have a default vhost for port 80, but no other default vhosts.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	<VirtualHost _default_:80>
	DocumentRoot /www/default
	...
	</VirtualHost>
	</PRE>
	A request to an unspecified address on port 80 is served from the
	default vhost any other request to an unspecified address and port
	is served from the main server.
	</BLOCKQUOTE>

	</UL>

	<HR>

	<H3><A NAME="migrate">Migrating a name-based vhost to an IP-based vhost</A></H3>

	<UL>

	<LI><STRONG>Setup:</STRONG>
	The name-based vhost with the hostname
	<SAMP>www.otherdomain.tld</SAMP> (from our <A HREF="#name">name-based</A>
	example, setup 2) should get its own IP address.
	To avoid problems with name servers or proxies who cached the old
	IP address for the name-based vhost we want to provide both variants
	during a migration phase.<BR>
	The solution is easy, because we can simply add the new IP address
	(<SAMP>111.22.33.66</SAMP>) to the <CODE>VirtualHost</CODE> directive.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	Port 80
	ServerName www.domain.tld
	DocumentRoot /www/domain

	NameVirtualHost 111.22.33.55

	<VirtualHost 111.22.33.55 111.22.33.66>
	DocumentRoot /www/otherdomain
	ServerName www.otherdomain.tld
	...
	</VirtualHost>

	<VirtualHost 111.22.33.55>
	DocumentRoot /www/subdomain
	ServerName www.sub.domain.tld
	ServerAlias *.sub.domain.tld
	...
	</VirtualHost>
	</PRE>
	The vhost can now be accessed through the new address (as an IP-based
	vhost) and through the old address (as a name-based vhost).
	</BLOCKQUOTE>

	</UL>

	<HR>

	<H3><A NAME="serverpath">Using the <CODE>ServerPath</CODE> directive</A></H3>

	<UL>

	<LI><STRONG>Setup:</STRONG>
	We have a server with two name-based vhosts. In order to match the correct
	virtual host a client must send the correct <CODE>Host:</CODE> header.
	Old HTTP/1.0 clients do not send such a header and Apache has no clue
	what vhost the client tried to reach (and serves the request from
	the primary vhost). To provide as much backward compatibility
	as possible we create a primary vhost which returns a single page
	containing links with an URL prefix to the name-based virtual hosts.
	<P>
	<STRONG>Server configuration:</STRONG>

	<BLOCKQUOTE><PRE>
	...
	NameVirtualHost 111.22.33.44

	<VirtualHost 111.22.33.44>
	# primary vhost
	DocumentRoot /www/subdomain
	RewriteEngine On
	RewriteRule ^/.* /www/subdomain/index.html
	...
	</VirtualHost>

	<VirtualHost 111.22.33.44>
	DocumentRoot /www/subdomain/sub1
	ServerName www.sub1.domain.tld
	ServerPath /sub1/
	RewriteEngine On
	RewriteRule ^(/sub1/.*) /www/subdomain$1
	...
	</VirtualHost>

	<VirtualHost 111.22.33.44>
	DocumentRoot /www/subdomain/sub2
	ServerName www.sub2.domain.tld
	ServerPath /sub2/
	RewriteEngine On
	RewriteRule ^(/sub2/.*) /www/subdomain$1
	...
	</VirtualHost>
	</PRE>
	Due to the <A HREF="../mod/core.html#serverpath"><CODE>ServerPath</CODE></A>
	directive a request to the
	URL <SAMP>http://www.sub1.domain.tld/sub1/</SAMP> is <EM>always</EM>
	served from the sub1-vhost. <BR>
	A request to the URL <SAMP>http://www.sub1.domain.tld/</SAMP>
	is only served from the sub1-vhost if the client sent a correct
	<CODE>Host:</CODE> header.
	If no <CODE>Host:</CODE> header is sent the client gets the
	information page from the primary host.<BR>
	Please note that there is one oddity: A request to
	<SAMP>http://www.sub2.domain.tld/sub1/</SAMP> is also served from
	the sub1-vhost if the client sent no <CODE>Host:</CODE> header. <BR>
	The <CODE>RewriteRule</CODE> directives are used to make sure that
	a client which sent a correct <CODE>Host:</CODE> header can use
	both URL variants, <EM>i.e.</EM>, with or without URL prefix.
	</BLOCKQUOTE>

	</UL>

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