Apache HTTP Server Version 2.4
Apache Module mod_authz_host
|Description:||Group authorizations based on host (name or IP address)|
The authorization providers implemented by
registered using the
directive. The directive can be referenced within a
as well as
files to control access to particular parts of the server.
Access can be controlled based on the client hostname or IP address.
In general, access restriction directives apply to all
access methods (
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
directive is used during the authorization phase to ensure that a user is allowed or
denied access to a resource. mod_authz_host extends the
authorization types with
Other authorization types may also be
used but may require that additional authorization modules be loaded.
These authorization providers affect which hosts can access an area of the server. Access can be controlled by hostname, IP Address, or IP Address range.
Since v2.4.8, expressions are supported within the host require directives.
ip provider allows access to the server
to be controlled based on the IP address of the remote client.
Require ip ip-address is specified,
then the request is allowed access if the IP address matches.
A full IP address:
Require ip 10.1.2.3 Require ip 192.168.1.104 192.168.1.205
An IP address of a host allowed access
A partial IP address:
Require ip 10.1 Require ip 10 172.20 192.168.2
The first 1 to 3 bytes of an IP address, for subnet restriction.
A network/netmask pair:
Require ip 10.1.0.0/255.255.0.0
A network a.b.c.d, and a netmask w.x.y.z. For more fine-grained subnet restriction.
A network/nnn CIDR specification:
Require ip 10.1.0.0/16
Similar to the previous case, except the netmask consists of nnn high-order 1 bits.
Note that the last three examples above match exactly the same set of hosts.
IPv6 addresses and IPv6 subnets can be specified as shown below:
Require ip 2001:db8::a00:20ff:fea7:ccea Require ip 2001:db8:1:1::a Require ip 2001:db8:2:1::/64 Require ip 2001:db8:3::/48
Note: As the IP addresses are parsed on startup, expressions are not evaluated at request time.
host provider allows access to the server
to be controlled based on the host name of the remote client.
Require host host-name is specified,
then the request is allowed access if the host name matches.
A (partial) domain-name
Require host example.org Require host .net example.edu
Hosts whose names match, or end in, this string are allowed
access. Only complete components are matched, so the above
example will match
foo.example.org but it will not
fooexample.org. This configuration will cause
Apache 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.
forward-dns provider allows access to the server
to be controlled based on simple host names. When
Require forward-dns host-name is specified,
all IP addresses corresponding to
are allowed access.
In contrast to the
host provider, this provider does not
rely on reverse DNS lookups: it simply queries the DNS for the host name
and allows a client if its IP matches. As a consequence, it will only
work with host names, not domain names. However, as the reverse DNS is
not used, it will work with clients which use a dynamic DNS service.
Require forward-dns bla.example.org
A client the IP of which is resolved from the name
bla.example.org will be granted access.
forward-dns provider was added in 2.4.19.
local provider allows access to the server if any
of the following conditions is true:
- the client address matches 127.0.0.0/8
- the client address is ::1
- both the client and the server address of the connection are the same
This allows a convenient way to match connections that originate from the local host:
If you are proxying content to your server, you need to be aware
that the client address will be the address of your proxy server,
not the address of the client, and so using the
directive in this context may not do what you mean. See
mod_remoteip for one possible solution to this