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      <h3>Apache HTTP Server Version 1.3</h3>
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    <h1 align="CENTER">Module mod_access</h1>

    <p>This module provides access control based on client
    hostname, IP address, or other characteristics of the client
    request.</p>

    <p><a href="module-dict.html#Status"
    rel="Help"><strong>Status:</strong></a> Base<br />
     <a href="module-dict.html#SourceFile"
    rel="Help"><strong>Source File:</strong></a> mod_access.c<br />
     <a href="module-dict.html#ModuleIdentifier"
    rel="Help"><strong>Module Identifier:</strong></a>
    access_module</p>

    <h2>Summary</h2>

    <p>The directives provided by mod_access are used in <code><a
    href="core.html#directory">&lt;Directory&gt;</a>, <a
    href="core.html#files">&lt;Files&gt;</a>,</code> and <code><a
    href="core.html#location">&lt;Location&gt;</a></code> sections
    as well as <code><a
    href="core.html#accessfilename">.htaccess</a></code> files to
    control access to particular parts of the server. Access can be
    controlled based on the client hostname, IP address, or other
    characteristics of the client request, as captured in <a
    href="../env.html">environment variables</a>. The
    <code>Allow</code> and <code>Deny</code> directives are used to
    specify which clients are or are not allowed access to the
    server, while the <code>Order</code> directive sets the default
    access state, and configures how the <code>Allow</code> and
    <code>Deny</code> directives interact with each other.</p>

    <p>Both host-based access restrictions and password-based
    authentication may be implemented simultaneously. In that case,
    the <a href="core.html#satisfy">Satisfy</a> directive is used
    to determine how the two sets of restrictions interact.</p>

    <p>In general, access restriction directives apply to all
    access methods (<code>GET</code>, <code>PUT</code>,
    <code>POST</code>, etc). This is the desired behavior in most
    cases. However, it is possible to restrict some methods, while
    leaving other methods unrestricted, by enclosing the directives
    in a <a href="core.html#limit">&lt;Limit&gt;</a> section.</p>

    <h2>Directives</h2>

    <ul>
      <li><a href="#allow">Allow</a></li>

      <li><a href="#deny">Deny</a></li>

      <li><a href="#order">Order</a></li>
    </ul>

    <p>See also <a href="core.html#satisfy">Satisfy</a> and <a
    href="core.html#require">Require</a>.</p>
    <hr />

    <h2><a id="allow" name="allow">Allow</a> <a id="allowfromenv"
    name="allowfromenv">directive</a></h2>

    <p>
     <a href="directive-dict.html#Syntax"
    rel="Help"><strong>Syntax:</strong></a> Allow from
    all|<em>host</em>|env=<em>env-variable</em>
    [<em>host</em>|env=<em>env-variable</em>] ...<br />
     <a href="directive-dict.html#Context"
    rel="Help"><strong>Context:</strong></a> directory,
    .htaccess<br />
     <a href="directive-dict.html#Override"
    rel="Help"><strong>Override:</strong></a> Limit<br />
     <a href="directive-dict.html#Status"
    rel="Help"><strong>Status:</strong></a> Base<br />
     <a href="directive-dict.html#Module"
    rel="Help"><strong>Module:</strong></a> mod_access</p>

    <p>The <code>Allow</code> directive affects which hosts can
    access an area of the server. Access can be controlled by
    hostname, IP Address, IP Address range, or by other
    characteristics of the client request captured in environment
    variables.</p>

    <p>The first argument to this directive is always
    <code>from</code>. The subsequent arguments can take three
    different forms. If <code>Allow from all</code> is specified,
    then all hosts are allowed access, subject to the configuration
    of the <code>Deny</code> and <code>Order</code> directives as
    discussed below. To allow only particular hosts or groups of
    hosts to access the server, the <em>host</em> can be specified
    in any of the following formats:</p>

    <dl>
      <dt>A (partial) domain-name</dt>

      <dd>Example: <code>Allow from apache.org</code><br />
       Hosts whose names match, or end in, this string are allowed
      access. Only complete components are matched, so the above
      example will match <code>foo.apache.org</code> but it will
      not match <code>fooapache.org</code>. This configuration will
      cause the server to perform a double reverse DNS lookup on the
      client IP address, regardless of the setting of the <a
      href="core.html#hostnamelookups">HostnameLookups</a>
      directive.  It will do a reverse DNS lookup on the IP address to
      find the associated hostname, and then do a forward lookup on
      the hostname to assure that it matches the original IP address.
      Only if the forward and reverse DNS are consistent and the
      hostname matches will access be allowed.</dd>

      <dt>A full IP address</dt>

      <dd>Example: <code>Allow from 10.1.2.3</code><br />
       An IP address of a host allowed access</dd>

      <dt>A partial IP address</dt>

      <dd>Example: <code>Allow from 10.1</code><br />
       The first 1 to 3 bytes of an IP address, for subnet
      restriction.</dd>

      <dt>A network/netmask pair</dt>

      <dd>Example: <code>Allow from
      10.1.0.0/255.255.0.0</code><br />
       A network a.b.c.d, and a netmask w.x.y.z. For more
      fine-grained subnet restriction. (Apache 1.3 and later)</dd>

      <dt>A network/nnn CIDR specification</dt>

      <dd>Example: <code>Allow from 10.1.0.0/16</code><br />
       Similar to the previous case, except the netmask consists of
      nnn high-order 1 bits. (Apache 1.3 and later)</dd>
    </dl>

    <p>Note that the last three examples above match exactly the
    same set of hosts.</p>

    <p>The third format of the arguments to the <code>Allow</code>
    directive allows access to the server to be controlled based on
    the existence of an <a href="../env.html">environment
    variable</a>. When <code>Allow from
    env=</code><em>env-variable</em> is specified, then the request
    is allowed access if the environment variable
    <em>env-variable</em> exists. The server provides the ability
    to set environment variables in a flexible way based on
    characteristics of the client request using the directives
    provided by <a href="mod_setenvif.html">mod_setenvif</a>.
    Therefore, this directive can be used to allow access based on
    such factors as the clients <code>User-Agent</code> (browser
    type), <code>Referer</code>, or other HTTP request header
    fields.</p>

    <p>Example:</p>

    <blockquote>
<pre>
SetEnvIf User-Agent ^KnockKnock/2\.0 let_me_in
&lt;Directory /docroot&gt;
    Order Deny,Allow
    Deny from all
    Allow from env=let_me_in
&lt;/Directory&gt;
</pre>
    </blockquote>

    <p>In this case, browsers with a user-agent string beginning
    with <tt>KnockKnock/2.0</tt> will be allowed access, and all
    others will be denied.</p>

    <p>See also <a href="#deny">Deny</a>, <a
    href="#order">Order</a> and <a
    href="mod_setenvif.html#setenvif">SetEnvIf</a>.</p>
    <hr />

    <h2><a id="deny" name="deny">Deny</a> <a id="denyfromenv"
    name="denyfromenv">directive</a></h2>

    <p>
     <a href="directive-dict.html#Syntax"
    rel="Help"><strong>Syntax:</strong></a> Deny from
    all|<em>host</em>|env=<em>env-variable</em>
    [<em>host</em>|env=<em>env-variable</em>] ...<br />
     <a href="directive-dict.html#Context"
    rel="Help"><strong>Context:</strong></a> directory,
    .htaccess<br />
     <a href="directive-dict.html#Override"
    rel="Help"><strong>Override:</strong></a> Limit<br />
     <a href="directive-dict.html#Status"
    rel="Help"><strong>Status:</strong></a> Base<br />
     <a href="directive-dict.html#Module"
    rel="Help"><strong>Module:</strong></a> mod_access</p>

    <p>This directive allows access to the server to be restricted
    based on hostname, IP address, or environment variables. The
    arguments for the <code>Deny</code> directive are identical to
    the arguments for the <a href="#allow">Allow</a> directive.</p>

    <p>See also <a href="#allow">Allow</a>, <a
    href="#order">Order</a> and <a
    href="mod_setenvif.html#setenvif">SetEnvIf</a>.</p>
    <hr />

    <h2><a id="order" name="order">Order directive</a></h2>

    <p>
     <a href="directive-dict.html#Syntax"
    rel="Help"><strong>Syntax:</strong></a> Order
    <em>ordering</em><br />
     <a href="directive-dict.html#Default"
    rel="Help"><strong>Default:</strong></a> <code>Order
    Deny,Allow</code><br />
     <a href="directive-dict.html#Context"
    rel="Help"><strong>Context:</strong></a> directory,
    .htaccess<br />
     <a href="directive-dict.html#Override"
    rel="Help"><strong>Override:</strong></a> Limit<br />
     <a href="directive-dict.html#Status"
    rel="Help"><strong>Status:</strong></a> Base<br />
     <a href="directive-dict.html#Module"
    rel="Help"><strong>Module:</strong></a> mod_access</p>

    <p>The <code>Order</code> directive controls the default access
    state and the order in which <a href="#allow">Allow</a> and <a
    href="#deny">Deny</a> directives are evaluated.
    <em>Ordering</em> is one of</p>

    <dl>
      <dt>Deny,Allow</dt>

      <dd>The <code>Deny</code> directives are evaluated before the
      <code>Allow</code> directives. Access is allowed by default.
      Any client which does not match a <code>Deny</code> directive
      or does match an <code>Allow</code> directive will be allowed
      access to the server.</dd>

      <dt>Allow,Deny</dt>

      <dd>The <code>Allow</code> directives are evaluated before
      the <code>Deny</code> directives. Access is denied by
      default. Any client which does not match an
      <code>Allow</code> directive or does match a
      <code>Deny</code> directive will be denied access to the
      server.</dd>

      <dt>Mutual-failure</dt>

      <dd>Only those hosts which appear on the <code>Allow</code>
      list and do not appear on the <code>Deny</code> list are
      granted access. This ordering has the same effect as
      <code>Order Allow,Deny</code> and is deprecated in favor of
      that configuration.</dd>
    </dl>

    <p>Keywords may only be separated by a comma; no whitespace is
    allowed between them. Note that in all cases every
    <code>Allow</code> and <code>Deny</code> statement is
    evaluated.</p>

    <p>In the following example, all hosts in the apache.org domain
    are allowed access; all other hosts are denied access.</p>

    <blockquote>
      <code>Order Deny,Allow<br />
       Deny from all<br />
       Allow from apache.org<br />
      </code>
    </blockquote>

    <p>In the next example, all hosts in the apache.org domain are
    allowed access, except for the hosts which are in the
    foo.apache.org subdomain, who are denied access. All hosts not
    in the apache.org domain are denied access because the default
    state is to deny access to the server.</p>

    <blockquote>
      <code>Order Allow,Deny<br />
       Allow from apache.org<br />
       Deny from foo.apache.org<br />
      </code>
    </blockquote>

    <p>On the other hand, if the <code>Order</code> in the last
    example is changed to <code>Deny,Allow</code>, all hosts will
    be allowed access. This happens because, regardless of the
    actual ordering of the directives in the configuration file,
    the <code>Allow from apache.org</code> will be evaluated last
    and will override the <code>Deny from foo.apache.org</code>.
    All hosts not in the <code>apache.org</code> domain will also
    be allowed access because the default state will change to
    <em>allow</em>.</p>

    <p>The presence of an <code>Order</code> directive can affect
    access to a part of the server even in the absence of
    accompanying <code>Allow</code> and <code>Deny</code>
    directives because of its effect on the default access state.
    For example,</p>

    <blockquote>
      <code>&lt;Directory /www&gt;<br />
       &nbsp;&nbsp;Order Allow,Deny<br />
       &lt;/Directory&gt;</code>
    </blockquote>

    <p>will deny all access to the <code>/www</code> directory
    because the default access state will be set to
    <em>deny</em>.</p>

    <p>The <code>Order</code> directive controls the order of
    access directive processing only within each phase of the
    server's configuration processing. This implies, for example,
    that an <code>Allow</code> or <code>Deny</code> directive
    occurring in a &lt;Location&gt; section will always be
    evaluated after an <code>Allow</code> or <code>Deny</code>
    directive occurring in a &lt;Directory&gt; section or
    <code>.htaccess</code> file, regardless of the setting of the
    <code>Order</code> directive. For details on the merging of
    configuration sections, see the documentation on <a
    href="../sections.html">How Directory, Location and Files
    sections work</a>.</p>

    <p>See also: <a href="#deny">Deny</a> and <a
    href="#allow">Allow</a>.     <hr />

    <h3 align="CENTER">Apache HTTP Server Version 1.3</h3>
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