Apache HTTP Server Version 2.3
Apache HTTP Server Version 2.3
| Description: | Replaces the apparent client remote IP address and hostname for the request with the IP address list presented by a proxies or a load balancer via the request headers. |
|---|---|
| Status: | Base |
| Module Identifier: | remoteip_module |
| Source File: | mod_remoteip.c |
This module is used to treat the remote host which initiated the request as the originating remote host as identified by httpd for the purposes of authorization and logging, even where that remote host is behind a load balancer, front end server, or proxy server.
The module replaces the apparent remote (client) IP/hostname for
the request with the IP address reported in the request header
configured with the RemoteIPHeader directive.
Once replaced as instructed, this apparent IP address is then used
for mod_authz_host features
<Require host>
and <Require ip>,
is reported by mod_status, and is recorded by
mod_log_config %a and %h
directives. It also determines the machine probed for an inetd
identity by mod_ident based on the
IdentityCheck configuration.
RemoteIPHeader RemoteIPInternalProxy RemoteIPInternalProxyList RemoteIPProxiesHeader RemoteIPTrustedProxy RemoteIPTrustedProxyList
Apache identifies the client with the connection's remote_ip value, and the connection remote_host and remote_logname are derived from this value. These fields play a role in authentication, authorization and logging and other purposes by other loadable modules.
mod_remoteip replaces the true remote_ip with the advertised remote_ip as provided by a proxy, for every evaluation of the client that occurs in the server, and resets the remote_host and remote_logname values to trigger a fresh dns or ident query of the remote IP address.
When multiple, comma delimited remote IP addresses are listed in the header value, they are processed in Right-to-Left order. Processing halts when a given remote IP address is not trusted to present the preceeding IP address. The header field is updated to this remaining list of unconfirmed IP addresses, or if all IP addresses were trusted, this header is removed from the request altogether.
In replacing the remote_ip, the module stores the list of intermediate
hosts in a remoteip-proxy-ip-list note, which mod_log_config
can record using the %{remoteip-proxy-ip-list}n format token.
If the administrator needs to store this as an additional header, this
same value can also be recording as a header using the directive
RemoteIPProxiesHeader.
RemoteIPInternalProxy
internal (intranet) proxies are registered.| Description: | Declare the header field which should be parsed for client IP addresses |
|---|---|
| Syntax: | RemoteIPHeader header-field |
| Context: | server config, virtual host |
| Status: | Base |
| Module: | mod_remoteip |
The RemoteIPHeader directive triggers
mod_remoteip to treat the value of the specified
header-field header as the client IP address, or list
of intermediate client IP addresses, subject to further configuration
of the RemoteIPInternalProxy and
RemoteIPTrustedProxy directives. Unless these
other directives are used, mod_remoteip will trust all
hosts presenting a RemoteIPHeader IP value.
RemoteIPHeader X-Client-IP
RemoteIPHeader X-Forwarded-For
| Description: | Declare client intranet IP addresses trusted to present the RemoteIPHeader value |
|---|---|
| Syntax: | RemoteIPInternalProxy proxy-ip|proxy-ip/subnet|hostname ... |
| Context: | server config, virtual host |
| Status: | Base |
| Module: | mod_remoteip |
The RemoteIPInternalProxy directive adds one
or more addresses (or address blocks) to trust as presenting a valid
RemoteIPHeader value of the client IP. Unlike the
RemoteIPTrustedProxy directive, any IP address
presented in this header, including private intranet addresses, are
trusted when passed from these proxies.
RemoteIPHeader X-Client-IP
RemoteIPTrustedProxy 10.0.2.0/24
RemoteIPTrustedProxy gateway.localdomain
| Description: | Declare client intranet IP addresses trusted to present the RemoteIPHeader value |
|---|---|
| Syntax: | RemoteIPInternalProxyList filename |
| Context: | server config, virtual host |
| Status: | Base |
| Module: | mod_remoteip |
The RemoteIPInternalProxyList directive specifies
a file parsed at startup, and builds a list of addresses (or address blocks)
to trust as presenting a valid RemoteIPHeader value of the client IP.
The '#' hash character designates a comment line, otherwise
each whitespace or newline separated entry is processed identically to
the RemoteIPInternalProxy directive.
RemoteIPHeader X-Client-IP
RemoteIPTrustedProxyList conf/trusted-proxies.lst
# Our internally trusted proxies;
10.0.2.0/24 #Everyone in the testing group
gateway.localdomain #The front end balancer
| Description: | Declare the header field which will record all intermediate IP addresses |
|---|---|
| Syntax: | RemoteIPProxiesHeader HeaderFieldName |
| Context: | server config, virtual host |
| Status: | Base |
| Module: | mod_remoteip |
The RemoteIPProxiesHeader directive specifies
a header into which mod_remoteip will collect a list of
all of the intermediate client IP addresses trusted to resolve the actual
remote IP. Note that intermediate RemoteIPTrustedProxy
addresses are recorded in this header, while any intermediate
RemoteIPInternalProxy addresses are discarded.
RemoteIPHeader X-Forwarded-For
RemoteIPProxiesHeader X-Forwarded-By
| Description: | Declare client intranet IP addresses trusted to present the RemoteIPHeader value |
|---|---|
| Syntax: | RemoteIPTrustedProxy proxy-ip|proxy-ip/subnet|hostname ... |
| Context: | server config, virtual host |
| Status: | Base |
| Module: | mod_remoteip |
The RemoteIPTrustedProxy directive adds one
or more addresses (or address blocks) to trust as presenting a valid
RemoteIPHeader value of the client IP. Unlike the
RemoteIPInternalProxy directive, any intranet
or private IP address reported by such proxies, including the 10/8, 172.16/12,
192.168/16, 169.254/16 and 127/8 blocks (or outside of the IPv6 public
2000::/3 block) are not trusted as the remote IP, and are left in the
RemoteIPHeader header's value.
RemoteIPHeader X-Forwarded-For
RemoteIPTrustedProxy 10.0.2.16/28
RemoteIPTrustedProxy proxy.example.com
| Description: | Declare client intranet IP addresses trusted to present the RemoteIPHeader value |
|---|---|
| Syntax: | RemoteIPTrustedProxyList filename |
| Context: | server config, virtual host |
| Status: | Base |
| Module: | mod_remoteip |
The RemoteIPTrustedProxyList directive specifies
a file parsed at startup, and builds a list of addresses (or address blocks)
to trust as presenting a valid RemoteIPHeader value of the client IP.
The '#' hash character designates a comment line, otherwise
each whitespace or newline seperated entry is processed identically to
the RemoteIPTrustedProxy directive.
RemoteIPHeader X-Forwarded-For
RemoteIPTrustedProxyList conf/trusted-proxies.lst
# Identified external proxies;
192.0.2.16/28 #wap phone group of proxies
proxy.isp.example.com #some well known ISP