geo

Describes the dependency of values of the specified variable on the client IP address. By default, the address is taken from the $remote_addr variable, but it can also be taken from another variable, for example:

geo $arg_remote_addr $geo {
    ...;
}

Since variables are evaluated only when used, the mere existence of even a large number of declared “geo” variables does not cause any extra costs for connection processing.

If the value of a variable does not represent a valid IP address then the “255.255.255.255” address is used.

Addresses are specified either as prefixes in CIDR notation (including individual addresses) or as ranges.

The following special parameters are also supported:

delete

deletes the specified network.

default

a value set to the variable if the client address does not match any of the specified addresses. When addresses are specified in CIDR notation, “0.0.0.0/0” and “::/0” can be used instead of default. When default is not specified, the default value will be an empty string.

include

includes a file with addresses and values. There can be several inclusions.

ranges

indicates that addresses are specified as ranges. This parameter should be the first. To speed up loading of a geo base, addresses should be put in ascending order.

Example:

geo $country {
    default        ZZ;
    include        conf/geo.conf;
    delete         127.0.0.0/16;

    127.0.0.0/24   US;
    127.0.0.1/32   RU;
    10.1.0.0/16    RU;
    192.168.1.0/24 UK;
}

The conf/geo.conf file could contain the following lines:

10.2.0.0/16    RU;
192.168.2.0/24 RU;

A value of the most specific match is used. For example, for the 127.0.0.1 address the value “RU” will be chosen, not “US”.

Example with ranges:

geo $country {
    ranges;
    default                   ZZ;
    127.0.0.0-127.0.0.0       US;
    127.0.0.1-127.0.0.1       RU;
    127.0.0.1-127.0.0.255     US;
    10.1.0.0-10.1.255.255     RU;
    192.168.1.0-192.168.1.255 UK;
}