IP Returner

A simple PHP script to tell a visitor's IP address and more information. This file is supposed to be on a webserver and can be configured by renaming config.php.sample to config.php.

Plain return

When the script is properly installed, one can visit/curl/wget the website to just receive one's public IP address. This is very useful in combination with other scripts (check out my snap-dyndns packages for example).

max@laptop ~> wget -qO - ip.nandus.net
91.62.68.1

Detailed return

Given the location of the script is ip.example.com, you can also receive more information about the HTTP headers or the IP's reverse lookup:

REMOTE_ADDR: 91.62.68.1
HTTP_X_FORWARDED_FOR: 91.62.68.1
HTTP_USER_AGENT: Mozilla/5.0 (X11; Linux x86_64; rv:48.0) Gecko/20100101 Firefox/50.0
HTTP_CLIENT_IP:
HTTP_X_FORWARDED:
HTTP_FORWARDED_FOR:
HTTP_FORWARDED:
HTTP_HOST: ip4.nandus.net
HTTP_URI:

HOSTNAME: p5B3E4401.dip0.t-ipconnect.de
IPv4 REVERSE LOOKUP: 91.62.68.1

Ideal domain setup

In order to use IPv4- and IPv6-only domains, you'll have to have control over the DNS nameserver records of your own domain.

Set ip.example.com to be IPv4 (A Record) and IPv6 (AAAA Record) of your webserver
Set ip4.example.com to only be the IPv4 address
Set ip6.example.com to only be the IPv6 address

Make sure that the script is available through all those domains. Now your browser will use the default route for the ip subdomain, and the v4 or v6 route for the respective subdomains ip4 and ip6.