What is returned in the header if there is no client address in the GeoIP databases?

Question

Nginx

The nginx docs describe the answer options:

$geoip_country_code - two-letter country code, for example, "RU", "US".
$geoip_country_code3 - three-letter country code, for example, "RUS", "USA".
$geoip_country_name - the (verbose) name of the country, for example, "Russian Federation", "United States", &c.

And what will be contained in the response when the server does not find the correspondence of the IP address to the country / city in its databases?

Answer 1

Nothing will be included in the response. Because $geoip_country_code will return false, then nginx simply won't pass a header that doesn't have a value.
Here a person almost broke his head because of this: serverfault.com/questions/463971/httpgeoipmodule-geoip-country-code-is-blank :)

Answer 2

I dare to suggest that
1. Unknown
2. 0
3. Undef

Answer 3

And what's stopping you from going to which thread 192.168 and see what it returns?