Given that it's a .jp subdomain, it's likely geared towards Japanese. Denisu is a valid shortening of DNS - the characters to spell it in katakana would be デニス, and potentially easier to remember for Japanese than "whatismyip," a fully qualified english query. Unless someone out there who knows more about Japanese than I do (admittedly, very little) can confirm that デニス or でにす is an actual word (google translate detected でにす as a phrase, giving me "su to the," which makes sense grammatically..)

Funny enough, it's also the romanjification of "dennis" (one of the first hits on google for it is dennis rodman's japanese wikipedia article).

Usually those services tell you your public IP.

This service says my IP is 10.1.3.46, and while technically correct, useless.

How can it give you your private IP address? I'm curious...

Is there a javascript call to list the IP addresses of any machine? That feels very insecure to me.

EDIT: Sorry I forgot to turn on my joke detector.

It probably gets it from the X-Forwarded-For HTTP reader inserted by his intranet proxy.

http://en.wikipedia.org/wiki/X-Forwarded-For

Uh, no? Knowing your public IP is valuable information sometimes and you need an external source to tell you that. Knowing your machine's IP is not something you should go to a website to look up, just check your local config.

Thanks for the feedback, it should now display the correct HTTP_X_FORWARDED_FOR-header if available.

Pics or it didn't happen.