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      This module provides access control based on client hostname, IP address, or other characteristics of the client request.
Status: Base
     Source File: mod_access.c
     Module Identifier:
    access_module
The directives provided by mod_access are used in <Directory>, <Files>, and <Location> sections
    as well as .htaccess 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 environment variables. The
    Allow and Deny directives are used to
    specify which clients are or are not allowed access to the
    server, while the Order directive sets the default
    access state, and configures how the Allow and
    Deny directives interact with each other.
Both host-based access restrictions and password-based authentication may be implemented simultaneously. In that case, the Satisfy directive is used to determine how the two sets of restrictions interact.
In general, access restriction directives apply to all
    access methods (GET, PUT,
    POST, 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 <Limit> section.
     Syntax: Allow from
    all|host|env=env-variable
    [host|env=env-variable] ...
     Context: directory,
    .htaccess
     Override: Limit
     Status: Base
     Module: mod_access
The Allow 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.
The first argument to this directive is always
    from. The subsequent arguments can take three
    different forms. If Allow from all is specified,
    then all hosts are allowed access, subject to the configuration
    of the Deny and Order directives as
    discussed below. To allow only particular hosts or groups of
    hosts to access the server, the host can be specified
    in any of the following formats:
Allow from apache.orgfoo.apache.org but it will
      not match fooapache.org. This configuration will
      cause the server to perform a double reverse DNS lookup on the
      client IP address, regardless of the setting of the HostnameLookups
      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.Allow from 10.1.2.3Allow from 10.1Allow from
      10.1.0.0/255.255.0.0Allow from 10.1.0.0/16Note that the last three examples above match exactly the same set of hosts.
The third format of the arguments to the Allow
    directive allows access to the server to be controlled based on
    the existence of an environment
    variable. When Allow from
    env=env-variable is specified, then the request
    is allowed access if the environment variable
    env-variable 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 mod_setenvif.
    Therefore, this directive can be used to allow access based on
    such factors as the clients User-Agent (browser
    type), Referer, or other HTTP request header
    fields.
Example:
SetEnvIf User-Agent ^KnockKnock/2\.0 let_me_in
<Directory /docroot>
    Order Deny,Allow
    Deny from all
    Allow from env=let_me_in
</Directory>
    
    In this case, browsers with a user-agent string beginning with KnockKnock/2.0 will be allowed access, and all others will be denied.
See also Deny, Order and SetEnvIf.
     Syntax: Deny from
    all|host|env=env-variable
    [host|env=env-variable] ...
     Context: directory,
    .htaccess
     Override: Limit
     Status: Base
     Module: mod_access
This directive allows access to the server to be restricted
    based on hostname, IP address, or environment variables. The
    arguments for the Deny directive are identical to
    the arguments for the Allow directive.
See also Allow, Order and SetEnvIf.
     Syntax: Order
    ordering
     Default: Order
    Deny,Allow
     Context: directory,
    .htaccess
     Override: Limit
     Status: Base
     Module: mod_access
The Order directive controls the default access
    state and the order in which Allow and Deny directives are evaluated.
    Ordering is one of
Deny directives are evaluated before the
      Allow directives. Access is allowed by default.
      Any client which does not match a Deny directive
      or does match an Allow directive will be allowed
      access to the server.Allow directives are evaluated before
      the Deny directives. Access is denied by
      default. Any client which does not match an
      Allow directive or does match a
      Deny directive will be denied access to the
      server.Allow
      list and do not appear on the Deny list are
      granted access. This ordering has the same effect as
      Order Allow,Deny and is deprecated in favor of
      that configuration.Keywords may only be separated by a comma; no whitespace is
    allowed between them. Note that in all cases every
    Allow and Deny statement is
    evaluated.
In the following example, all hosts in the apache.org domain are allowed access; all other hosts are denied access.
      Order Deny,Allow
       Deny from all
       Allow from apache.org
      
    
    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.
      Order Allow,Deny
       Allow from apache.org
       Deny from foo.apache.org
      
    
    On the other hand, if the Order in the last
    example is changed to Deny,Allow, all hosts will
    be allowed access. This happens because, regardless of the
    actual ordering of the directives in the configuration file,
    the Allow from apache.org will be evaluated last
    and will override the Deny from foo.apache.org.
    All hosts not in the apache.org domain will also
    be allowed access because the default state will change to
    allow.
The presence of an Order directive can affect
    access to a part of the server even in the absence of
    accompanying Allow and Deny
    directives because of its effect on the default access state.
    For example,
      <Directory /www>
         Order Allow,Deny
       </Directory>
    
    will deny all access to the /www directory
    because the default access state will be set to
    deny.
The Order directive controls the order of
    access directive processing only within each phase of the
    server's configuration processing. This implies, for example,
    that an Allow or Deny directive
    occurring in a <Location> section will always be
    evaluated after an Allow or Deny
    directive occurring in a <Directory> section or
    .htaccess file, regardless of the setting of the
    Order directive. For details on the merging of
    configuration sections, see the documentation on How Directory, Location and Files
    sections work.
 
    