208651a016b098f4fa1f6279559f104d70f1632dtakashi<?xml version='1.0' encoding='UTF-8' ?>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<!DOCTYPE manualpage SYSTEM "/style/manualpage.dtd">

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<?xml-stylesheet type="text/xsl" href="/style/manual.en.xsl"?>

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d5d794fc2f4cc9ca6d6da17cfa2cdcd8d244bacdnd

7db9f691a00ead175b03335457ca296a33ddf31bnd<manualpage metafile="name-based.xml.meta">

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<parentdocument href="./">Virtual Hosts</parentdocument>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<title>Name-based Virtual Host Support</title>

208651a016b098f4fa1f6279559f104d70f1632dtakashi

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<summary>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <p>This document describes when and how to use name-based virtual hosts.</p>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki</summary>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<seealso><a href="ip-based.html">IP-based Virtual Host Support</a></seealso>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<seealso><a href="details.html">An In-Depth Discussion of Virtual Host Matching</a></seealso>

208651a016b098f4fa1f6279559f104d70f1632dtakashi<seealso><a href="mass.html">Dynamically configured mass virtual hosting</a></seealso>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<seealso><a href="examples.html">Virtual Host examples for common setups</a></seealso>

208651a016b098f4fa1f6279559f104d70f1632dtakashi

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<section id="namevip"><title>Name-based vs. IP-based Virtual Hosts</title>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

208651a016b098f4fa1f6279559f104d70f1632dtakashi <p><a href="ip-based.html">IP-based virtual hosts</a> use the IP address of the connection to

208651a016b098f4fa1f6279559f104d70f1632dtakashi determine the correct virtual host to serve. Therefore you need to

51518469f1207f11cd9a00d303838b86fe27b55cyoshiki have a separate IP address for each host.</p>

208651a016b098f4fa1f6279559f104d70f1632dtakashi

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <p>With name-based virtual hosting, the server relies on the client to

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki report the hostname as part of the HTTP headers. Using this technique,

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki many different hosts can share the same IP address.</p>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

208651a016b098f4fa1f6279559f104d70f1632dtakashi <p>Name-based virtual hosting is usually simpler, since you need

c68796f705286dc3fd9c0d23a57fe459b04de864takashi only configure your DNS server to map each hostname to the correct

f099908f1df377e6f6ee90c5732fcd30f253012eyoshiki IP address and then configure the Apache HTTP Server to recognize

f099908f1df377e6f6ee90c5732fcd30f253012eyoshiki the different hostnames. Name-based virtual hosting also eases

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki the demand for scarce IP addresses. Therefore you should use

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki name-based virtual hosting unless you are using equipment

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki that explicitly demands IP-based hosting. Historical reasons for

208651a016b098f4fa1f6279559f104d70f1632dtakashi IP-based virtual hosting based on client support are no longer

208651a016b098f4fa1f6279559f104d70f1632dtakashi applicable to a general-purpose web server.</p>

208651a016b098f4fa1f6279559f104d70f1632dtakashi

208651a016b098f4fa1f6279559f104d70f1632dtakashi <p> Name-based virtual hosting builds off of the IP-based virtual host

208651a016b098f4fa1f6279559f104d70f1632dtakashi selection algorithm, meaning that searches for the proper server name

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki occur only between virtual hosts that have the best IP-based address.</p>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

208651a016b098f4fa1f6279559f104d70f1632dtakashi</section>

208651a016b098f4fa1f6279559f104d70f1632dtakashi

208651a016b098f4fa1f6279559f104d70f1632dtakashi<section id="alg"><title>How the server selects the proper name-based virtual host</title>

208651a016b098f4fa1f6279559f104d70f1632dtakashi

208651a016b098f4fa1f6279559f104d70f1632dtakashi <p>It is important to recognize that the first step in name-based virtual

208651a016b098f4fa1f6279559f104d70f1632dtakashi host resolution is IP-based resolution. Name-based virtual host

208651a016b098f4fa1f6279559f104d70f1632dtakashi resolution only chooses the most appropriate name-based virtual host

208651a016b098f4fa1f6279559f104d70f1632dtakashi after narrowing down the candidates to the best IP-based match. Using a wildcard (*)

208651a016b098f4fa1f6279559f104d70f1632dtakashi for the IP address in all of the VirtualHost directives makes this

208651a016b098f4fa1f6279559f104d70f1632dtakashi IP-based mapping irrelevant.</p>

208651a016b098f4fa1f6279559f104d70f1632dtakashi

208651a016b098f4fa1f6279559f104d70f1632dtakashi <p>When a request arrives, the server will find the best (most specific) matching

208651a016b098f4fa1f6279559f104d70f1632dtakashi <directive type="section" module="core">VirtualHost</directive> argument based on

0e1bb310657b9d1540737c542e337abe37c8453bkawai the IP address and port used by the request. If there is more than one virtual host

10506784730138cf41a16c81c0b3d78224c2a2dekawai containing this best-match address and port combination, Apache will further

208651a016b098f4fa1f6279559f104d70f1632dtakashi compare the <directive module="core" >ServerName</directive> and <directive

208651a016b098f4fa1f6279559f104d70f1632dtakashi module="core">ServerAlias</directive> directives to the server name

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki present in the request.</p>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <p>If you omit the <directive module="core">ServerName</directive>

208651a016b098f4fa1f6279559f104d70f1632dtakashi directive from any name-based virtual host, the server will default

208651a016b098f4fa1f6279559f104d70f1632dtakashi to a fully qualified domain name (FQDN) derived from the system hostname.

208651a016b098f4fa1f6279559f104d70f1632dtakashi This implicitly set server name can lead to counter-intuitive virtual host

208651a016b098f4fa1f6279559f104d70f1632dtakashi matching and is discouraged.</p>

c68796f705286dc3fd9c0d23a57fe459b04de864takashi

208651a016b098f4fa1f6279559f104d70f1632dtakashi <section id="defaultvhost"><title>The default name-based vhost for an IP and port combination </title>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <p> If no matching ServerName or ServerAlias is found in the set of

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki virtual hosts containing the most specific matching IP address and port

208651a016b098f4fa1f6279559f104d70f1632dtakashi combination, then <strong>the first listed virtual host</strong> that

208651a016b098f4fa1f6279559f104d70f1632dtakashi matches that will be used.</p></section>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki</section>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<section id="using"><title>Using Name-based Virtual Hosts</title>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki<related>

208651a016b098f4fa1f6279559f104d70f1632dtakashi <modulelist>

208651a016b098f4fa1f6279559f104d70f1632dtakashi <module>core</module>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki </modulelist>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

208651a016b098f4fa1f6279559f104d70f1632dtakashi <directivelist>

208651a016b098f4fa1f6279559f104d70f1632dtakashi <directive module="core">DocumentRoot</directive>

c68796f705286dc3fd9c0d23a57fe459b04de864takashi <directive module="core">ServerAlias</directive>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <directive module="core">ServerName</directive>

c68796f705286dc3fd9c0d23a57fe459b04de864takashi <directive module="core" type="section">VirtualHost</directive>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki </directivelist>

c68796f705286dc3fd9c0d23a57fe459b04de864takashi</related>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <p>The first step is to create a <directive type="section"

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki module="core">VirtualHost</directive> block for

208651a016b098f4fa1f6279559f104d70f1632dtakashi each different host that you would like to serve. Inside each <directive type="section"

208651a016b098f4fa1f6279559f104d70f1632dtakashi module="core">VirtualHost</directive> block, you will need at minimum a

208651a016b098f4fa1f6279559f104d70f1632dtakashi <directive module="core">ServerName</directive> directive to designate

208651a016b098f4fa1f6279559f104d70f1632dtakashi which host is served and a <directive module="core">DocumentRoot</directive>

208651a016b098f4fa1f6279559f104d70f1632dtakashi directive to show where in the filesystem the content for that host

208651a016b098f4fa1f6279559f104d70f1632dtakashi lives.</p>

208651a016b098f4fa1f6279559f104d70f1632dtakashi

208651a016b098f4fa1f6279559f104d70f1632dtakashi <note><title>Main host goes away</title>

208651a016b098f4fa1f6279559f104d70f1632dtakashi <p> Any request that doesn't match an existing <directive type="section"

208651a016b098f4fa1f6279559f104d70f1632dtakashi module="core">VirtualHost</directive> is handled by the global

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki server configuration, regardless of the hostname or ServerName.</p>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

208651a016b098f4fa1f6279559f104d70f1632dtakashi <p> When you add a name-based virtual host to an existing server, and

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki the virtual host arguments match preexisting IP and port combinations,

208651a016b098f4fa1f6279559f104d70f1632dtakashi requests will now be handled by an explicit virtual host. In this case,

208651a016b098f4fa1f6279559f104d70f1632dtakashi it's usually wise to create a <a href="#defaultvhost">default virtual host</a>

208651a016b098f4fa1f6279559f104d70f1632dtakashi with a <directive module="core">ServerName</directive> matching that of

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki the base server. New domains on the same interface and port, but

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki requiring separate configurations, can then be added as subsequent (non-default)

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki virtual hosts.</p>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki </note>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <note><title>ServerName inheritance</title>

208651a016b098f4fa1f6279559f104d70f1632dtakashi <p> It is best to always explicitly list a <directive module="core"

208651a016b098f4fa1f6279559f104d70f1632dtakashi >ServerName</directive> in every name-based virtual host.</p>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <p>If a <directive module="core">VirtualHost</directive> doesn't specify

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki a <directive module="core">ServerName</directive>, a server name will be

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki inherited from the base server configuration. If no server name was

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki specified globally, one is detected at startup through reverse DNS resolution

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki of the first listening address. In either case, this inherited server name

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki will influence name-based virtual host resolution, so it is best to always

208651a016b098f4fa1f6279559f104d70f1632dtakashi explicitly list a <directive module="core">ServerName</directive> in every

208651a016b098f4fa1f6279559f104d70f1632dtakashi name-based virtual host.</p>

f099908f1df377e6f6ee90c5732fcd30f253012eyoshiki </note>

f099908f1df377e6f6ee90c5732fcd30f253012eyoshiki

c68796f705286dc3fd9c0d23a57fe459b04de864takashi <p>For example, suppose that you are serving the domain

f099908f1df377e6f6ee90c5732fcd30f253012eyoshiki <code>www.example.com</code> and you wish to add the virtual host

f099908f1df377e6f6ee90c5732fcd30f253012eyoshiki <code>other.example.com</code>, which points at the same IP address.

c68796f705286dc3fd9c0d23a57fe459b04de864takashi Then you simply add the following to <code>httpd.conf</code>:</p>

208651a016b098f4fa1f6279559f104d70f1632dtakashi

c68796f705286dc3fd9c0d23a57fe459b04de864takashi <highlight language="config">

208651a016b098f4fa1f6279559f104d70f1632dtakashi&lt;VirtualHost *:80&gt;

f099908f1df377e6f6ee90c5732fcd30f253012eyoshiki # This first-listed virtual host is also the default for *:80

208651a016b098f4fa1f6279559f104d70f1632dtakashi ServerName www.example.com

208651a016b098f4fa1f6279559f104d70f1632dtakashi ServerAlias example.com

208651a016b098f4fa1f6279559f104d70f1632dtakashi DocumentRoot "/www/domain"

208651a016b098f4fa1f6279559f104d70f1632dtakashi&lt;/VirtualHost&gt;

f099908f1df377e6f6ee90c5732fcd30f253012eyoshiki

208651a016b098f4fa1f6279559f104d70f1632dtakashi&lt;VirtualHost *:80&gt;

208651a016b098f4fa1f6279559f104d70f1632dtakashi ServerName other.example.com

208651a016b098f4fa1f6279559f104d70f1632dtakashi DocumentRoot "/www/otherdomain"

208651a016b098f4fa1f6279559f104d70f1632dtakashi&lt;/VirtualHost&gt;

5f3c6037eb417c884d8e6b1de96d88d2b156d749kawai </highlight>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <p>You can alternatively specify an explicit IP address in place of the

51518469f1207f11cd9a00d303838b86fe27b55cyoshiki <code>*</code> in <directive type="section" module="core"

208651a016b098f4fa1f6279559f104d70f1632dtakashi >VirtualHost</directive> directives. For example, you might want to do this

51518469f1207f11cd9a00d303838b86fe27b55cyoshiki in order to run some name-based virtual hosts on one IP address, and either

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki IP-based, or another set of name-based virtual hosts on another address.</p>

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki <p>Many servers want to be accessible by more than one name. This is

43b8f5cebbf28df342fcdda8fa1992c28eaa6309yoshiki possible with the <directive module="core">ServerAlias</directive>

directive, placed inside the <directive type="section" module="core"

>VirtualHost</directive> section. For example in the first <directive

type="section" module="core">VirtualHost</directive> block above, the

<directive module="core">ServerAlias</directive> directive indicates that

the listed names are other names which people can use to see that same

web site:</p>

<highlight language="config">

ServerAlias example.com *.example.com

</highlight>

<p>then requests for all hosts in the <code>example.com</code> domain will

be served by the <code>www.example.com</code> virtual host. The wildcard

characters <code>*</code> and <code>?</code> can be used to match names.

Of course, you can't just make up names and place them in <directive

module="core">ServerName</directive> or <code>ServerAlias</code>. You must

first have your DNS server properly configured to map those names to an IP

address associated with your server.</p>

<p>Name-based virtual hosts for the best-matching set of <directive

type="section" module="core">virtualhost</directive>s are processed

in the order they appear in the configuration. The first matching <directive

module="core">ServerName</directive> or <directive module="core"

>ServerAlias</directive> is used, with no different precedence for wildcards

(nor for ServerName vs. ServerAlias). </p>

<p>The complete list of names in the <directive module="core"

>VirtualHost</directive>

directive are treated just like a (non wildcard)

<directive module="core">ServerAlias</directive>.</p>

<p>Finally, you can fine-tune the configuration of the virtual hosts

by placing other directives inside the <directive type="section"

module="core">VirtualHost</directive> containers. Most directives can be

placed in these containers and will then change the configuration only of

the relevant virtual host. To find out if a particular directive is allowed,

check the <a href="/mod/directive-dict.html#Context">Context</a> of the

directive. Configuration directives set in the <em>main server context</em>

(outside any <directive type="section" module="core">VirtualHost</directive>

container) will be used only if they are not overridden by the virtual host

settings.</p>

</section>

</manualpage>