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<manualpage metafile="examples.xml.meta">
<parentdocument href="./">Virtual Hosts</parentdocument>
    <title>VirtualHost Examples</title>

<summary>

    <p>This document attempts to answer the commonly-asked questions about
    setting up <a href="index.html">virtual hosts</a>. These scenarios are those involving multiple
    web sites running on a single server, via <a
    href="name-based.html">name-based</a> or <a
    href="ip-based.html">IP-based</a> virtual hosts.
    </p>

</summary>

  <section id="purename"><title>Running several name-based web
    sites on a single IP address.</title>

    <p>Your server has a single IP address, and multiple aliases (CNAMES)
    point to this machine in DNS. You want to run a web server for
    <code>www.example.com</code> and <code>www.example.org</code> on this
    machine.</p>

    <note><title>Note</title><p>Creating virtual
          host configurations on your Apache server does not magically
          cause DNS entries to be created for those host names. You
          <em>must</em> have the names in DNS, resolving to your IP
          address, or nobody else will be able to see your web site. You
          can put entries in your <code>hosts</code> file for local
          testing, but that will work only from the machine with those
          <code>hosts</code> entries.</p>
    </note>

    <highlight language="config">
# Ensure that Apache listens on port 80
Listen 80
&lt;VirtualHost *:80&gt;
    DocumentRoot /www/example1
    ServerName www.example.com
  
    # Other directives here
&lt;/VirtualHost&gt;

&lt;VirtualHost *:80&gt;
    DocumentRoot /www/example2
    ServerName www.example.org

    # Other directives here
&lt;/VirtualHost&gt;
    </highlight>

    <p>The asterisks match all addresses, so the main server serves no
    requests. Due to the fact that the virtual host with
    <code>ServerName www.example.com</code> is first
    in the configuration file, it has the highest priority and can be seen
    as the <cite>default</cite> or <cite>primary</cite> server. That means
    that if a request is received that does not match one of the specified
    <code>ServerName</code> directives, it will be served by this first
    <code>VirtualHost</code>.</p>

    <note>
            <title>Note</title>

           <p>You can, if you wish, replace <code>*</code> with the actual
           IP address of the system, when you don't care to discriminate based
           on the IP address or port.</p>

           <p>However, it is additionally useful to use <code>*</code>
           on systems where the IP address is not predictable - for
           example if you have a dynamic IP address with your ISP, and
           you are using some variety of dynamic DNS solution. Since
           <code>*</code> matches any IP address, this configuration
           would work without changes whenever your IP address
           changes.</p>
    </note>

    <p>The above configuration is what you will want to use in almost
    all name-based virtual hosting situations. The only thing that this
    configuration will not work for, in fact, is when you are serving
    different content based on differing IP addresses or ports.</p>

  </section>

  <section id="twoips"><title>Name-based hosts on more than one
    IP address.</title>

    <note>
      <title>Note</title>
      <p>Any of the techniques discussed here can be extended to any
      number of IP addresses.</p>
    </note>

    <p>The server has two IP addresses. On one (<code>172.20.30.40</code>), we
    will serve the "main" server, <code>server.example.com</code> and on the
    other (<code>172.20.30.50</code>), we will serve two or more virtual hosts.</p>

    <highlight language="config">
Listen 80

# This is the "main" server running on 172.20.30.40
ServerName server.example.com
DocumentRoot /www/mainserver

&lt;VirtualHost 172.20.30.50&gt;
    DocumentRoot /www/example1
    ServerName www.example.com
    
    # Other directives here ...
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.50&gt;
    DocumentRoot /www/example2
    ServerName www.example.org
    
    # Other directives here ...
&lt;/VirtualHost&gt;
    </highlight>

    <p>Any request to an address other than <code>172.20.30.50</code> will be
    served from the main server. A request to <code>172.20.30.50</code> with an
    unknown hostname, or no <code>Host:</code> header, will be served from
    <code>www.example.com</code>.</p>

  </section>

  <section id="intraextra"><title>Serving the same content on
    different IP addresses (such as an internal and external
    address).</title>

    <p>The server machine has two IP addresses (<code>192.168.1.1</code>
    and <code>172.20.30.40</code>). The machine is sitting between an
    internal (intranet) network and an external (internet) network. Outside
    of the network, the name <code>server.example.com</code> resolves to
    the external address (<code>172.20.30.40</code>), but inside the
    network, that same name resolves to the internal address
    (<code>192.168.1.1</code>).</p>

    <p>The server can be made to respond to internal and external requests
    with the same content, with just one <code>VirtualHost</code>
    section.</p>

    <highlight language="config">
&lt;VirtualHost 192.168.1.1 172.20.30.40&gt;
    DocumentRoot /www/server1
    ServerName server.example.com
    ServerAlias server
&lt;/VirtualHost&gt;
    </highlight>

    <p>Now requests from both networks will be served from the same
    <code>VirtualHost</code>.</p>

    <note>
          <title>Note:</title><p>On the internal
          network, one can just use the name <code>server</code> rather
          than the fully qualified host name
          <code>server.example.com</code>.</p>

          <p>Note also that, in the above example, you can replace the list
          of IP addresses with <code>*</code>, which will cause the server to
          respond the same on all addresses.</p>
    </note>

  </section>

  <section id="port"><title>Running different sites on different
    ports.</title>

    <p>You have multiple domains going to the same IP and also want to
    serve multiple ports.  The example below illustrates that the name-matching
    takes place after the best matching IP address and port combination
    is determined.</p>

    <highlight language="config">
Listen 80
Listen 8080

&lt;VirtualHost 172.20.30.40:80&gt;
    ServerName www.example.com
    DocumentRoot /www/domain-80
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.40:8080&gt;
    ServerName www.example.com
    DocumentRoot /www/domain-8080
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.40:80&gt;
    ServerName www.example.org
    DocumentRoot /www/otherdomain-80
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.40:8080&gt;
    ServerName www.example.org
    DocumentRoot /www/otherdomain-8080
&lt;/VirtualHost&gt;
    </highlight>

  </section>

  <section id="ip"><title>IP-based virtual hosting</title>

    <p>The server has two IP addresses (<code>172.20.30.40</code> and
    <code>172.20.30.50</code>) which resolve to the names
    <code>www.example.com</code> and <code>www.example.org</code>
    respectively.</p>

    <highlight language="config">
Listen 80

&lt;VirtualHost 172.20.30.40&gt;
    DocumentRoot /www/example1
    ServerName www.example.com
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.50&gt;
    DocumentRoot /www/example2
    ServerName www.example.org
&lt;/VirtualHost&gt;
    </highlight>

    <p>Requests for any address not specified in one of the
    <code>&lt;VirtualHost&gt;</code> directives (such as
    <code>localhost</code>, for example) will go to the main server, if
    there is one.</p>

  </section>

  <section id="ipport"><title>Mixed port-based and ip-based virtual
  hosts</title>

    <p>The server machine has two IP addresses (<code>172.20.30.40</code> and
    <code>172.20.30.50</code>) which resolve to the names
    <code>www.example.com</code> and <code>www.example.org</code>
    respectively. In each case, we want to run hosts on ports 80 and
    8080.</p>

    <highlight language="config">
Listen 172.20.30.40:80
Listen 172.20.30.40:8080
Listen 172.20.30.50:80
Listen 172.20.30.50:8080

&lt;VirtualHost 172.20.30.40:80&gt;
    DocumentRoot /www/example1-80
    ServerName www.example.com
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.40:8080&gt;
    DocumentRoot /www/example1-8080
    ServerName www.example.com
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.50:80&gt;
    DocumentRoot /www/example2-80
    ServerName www.example.org
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.50:8080&gt;
    DocumentRoot /www/example2-8080
    ServerName www.example.org
&lt;/VirtualHost&gt;
    </highlight>

  </section>

  <section id="mixed"><title>Mixed name-based and IP-based
    vhosts</title>

    <p>Any address mentioned in the argument to a virtualhost that never
    appears in another virtual host is a strictly IP-based virtual host.</p>

    <highlight language="config">
Listen 80
&lt;VirtualHost 172.20.30.40&gt;
    DocumentRoot /www/example1
    ServerName www.example.com
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.40&gt;
    DocumentRoot /www/example2
    ServerName www.example.org
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.40&gt;
    DocumentRoot /www/example3
    ServerName www.example.net
&lt;/VirtualHost&gt;

# IP-based
&lt;VirtualHost 172.20.30.50&gt;
    DocumentRoot /www/example4
    ServerName www.example.edu
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.60&gt;
    DocumentRoot /www/example5
    ServerName www.example.gov
&lt;/VirtualHost&gt;
    </highlight>

  </section>

    <section id="proxy"><title>Using <code>Virtual_host</code> and
    mod_proxy together</title>

    <p>The following example allows a front-end machine to proxy a
    virtual host through to a server running on another machine. In the
    example, a virtual host of the same name is configured on a machine
    at <code>192.168.111.2</code>. The <directive
    module="mod_proxy">ProxyPreserveHost On</directive> directive is
    used so that the desired hostname is passed through, in case we are
    proxying multiple hostnames to a single machine.</p>

    <highlight language="config">
&lt;VirtualHost *:*&gt;
    ProxyPreserveHost On
    ProxyPass / http://192.168.111.2/
    ProxyPassReverse / http://192.168.111.2/
    ServerName hostname.example.com
&lt;/VirtualHost&gt;
    </highlight>

    </section>

  <section id="default"><title>Using <code>_default_</code>
    vhosts</title>

    <section id="defaultallports"><title><code>_default_</code> vhosts
    for all ports</title>

    <p>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>

    <highlight language="config">
&lt;VirtualHost _default_:*&gt;
    DocumentRoot /www/default
&lt;/VirtualHost&gt;
    </highlight>

    <p>Using such a default vhost with a wildcard port effectively prevents
    any request going to the main server.</p>

    <p>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).</p>

    <p>You can use <directive module="mod_alias">AliasMatch</directive> or
    <directive module="mod_rewrite">RewriteRule</directive> to rewrite any
    request to a single information page (or script).</p>
    </section>

    <section id="defaultdifferentports"><title><code>_default_</code> vhosts
    for different ports</title>

    <p>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>

    <highlight language="config">
&lt;VirtualHost _default_:80&gt;
    DocumentRoot /www/default80
    # ...
&lt;/VirtualHost&gt;

&lt;VirtualHost _default_:*&gt;
    DocumentRoot /www/default
    # ...
&lt;/VirtualHost&gt;
    </highlight>

    <p>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.</p>
    </section>

    <section id="defaultoneport"><title><code>_default_</code> vhosts
    for one port</title>

    <p>We want to have a default vhost for port 80, but no other default
    vhosts.</p>

    <highlight language="config">
&lt;VirtualHost _default_:80&gt;
DocumentRoot /www/default
...
&lt;/VirtualHost&gt;
    </highlight>

    <p>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.</p>

    <p>Any use of <code>*</code> in a virtual host declaration will have
    higher precedence than <code>_default_</code>.</p>

    </section>

  </section>

  <section id="migrate"><title>Migrating a name-based vhost to an
    IP-based vhost</title>

    <p>The name-based vhost with the hostname
    <code>www.example.org</code> (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.</p>

    <p>
     The solution is easy, because we can simply add the new IP address
    (<code>172.20.30.50</code>) to the <code>VirtualHost</code>
    directive.</p>

    <highlight language="config">
Listen 80
ServerName www.example.com
DocumentRoot /www/example1

&lt;VirtualHost 172.20.30.40 172.20.30.50&gt;
    DocumentRoot /www/example2
    ServerName www.example.org
    # ...
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.40&gt;
    DocumentRoot /www/example3
    ServerName www.example.net
    ServerAlias *.example.net
    # ...
&lt;/VirtualHost&gt;
    </highlight>

    <p>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).</p>

  </section>

  <section id="serverpath"><title>Using the <code>ServerPath</code>
  directive</title>

    <p>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>

    <highlight language="config">
&lt;VirtualHost 172.20.30.40&gt;
    # primary vhost
    DocumentRoot /www/subdomain
    RewriteEngine On
    RewriteRule . /www/subdomain/index.html
    # ...
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.40&gt;
DocumentRoot /www/subdomain/sub1
    ServerName www.sub1.domain.tld
    ServerPath /sub1/
    RewriteEngine On
    RewriteRule ^(/sub1/.*) /www/subdomain$1
    # ...
&lt;/VirtualHost&gt;

&lt;VirtualHost 172.20.30.40&gt;
    DocumentRoot /www/subdomain/sub2
    ServerName www.sub2.domain.tld
    ServerPath /sub2/
    RewriteEngine On
    RewriteRule ^(/sub2/.*) /www/subdomain$1
    # ...
&lt;/VirtualHost&gt;
    </highlight>

    <p>Due to the <directive module="core">ServerPath</directive>
    directive a request to the URL
    <code>http://www.sub1.domain.tld/sub1/</code> is <em>always</em> served
    from the sub1-vhost.<br /> A request to the URL
    <code>http://www.sub1.domain.tld/</code> 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.</p>

    <p>Please note that there is one oddity: A request to
    <code>http://www.sub2.domain.tld/sub1/</code> is also served from the
    sub1-vhost if the client sent no <code>Host:</code> header.</p>

    <p>The <directive module="mod_rewrite">RewriteRule</directive> 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.</p>

  </section>

</manualpage>
