I have been using the IP address http://188.8.131.52/ for a long time now, to check my internet connection speed. All this time I knew that it was an Airtel website, but I never knew the site's name!! As I switched from Airtel to BSNL, then from Internet Explorer to Firefox, then from Desktop PC to Laptop.... I kept migrating the bookmarks (this one in particular).
Today, I decided, "what the heck... I want the server'e name...". I had heard of a protocol called RARP, I thought it'd help. But it's define:RARP (on Google) returned 'Reverse Address Resolution Protocol is a method of mapping the physical Ethernet address to the IP address of the host'. So I stopped following that route immediately.
Then, I turned to Google again. I serached for 'IP address to site name', and the first two results turned out to be great utilities!!!
Find Ip Address - resolving IP addresses into DNS names
One of these can even give you the city the server is located in!!!
So, that IP turned out to be speed.touchtelindia.net, and it is situated in Chennai.
(update 11/Oct/2007: the server's name is now http://speed.airtelbroadband.in/ and the speed test is now java based; really nice, you should check it out. Oh, and my connection speed is still decently close to 256 that BSNL promises!)
PS: Did I mention that, except for a few exceptions, BSNL never gave a reading below 260 Kbps in these speed tests!!! (I have seen the results ranging from 300s to 400s and sometimes even in 700s!!! That's way beyond what I am paying for... 256 Kbps :) BSNL is just great...)