Another measure of the size of the IPv6 address space... Back on World IPv6 Day in June 2011, Dartware had a barbecue. (Why? Because the burgers had 128 (bacon) bits and we served IP(A) to drink :-) You can see some photos at: http://www.networkworld.com/community/blog/scenes-ipv6-day-barbecue But we came up with another interesting measure for the vastness of the IPv6 address space: If an IPv4 hamburger patty has 2^32 (4.2 billion) unique addresses in its 1/4 inch thickness, how thick would an IPv6 hamburger be (with 2^128 unique addresses)? The answer is... 53 billion light-years. It's straightforward unit conversions. There are 2^96 IPv4 Hamburgers at a quarter-inch apiece. That's 2^96 inches/4 (2^94 inches). Switching to decimal units, 1.98x10^32 inches; 1.65x10^27 feet; 3.13x10^23 miles; and then continuing to convert to light-years. A good tool for this kind of wacky unit conversion is Frink (http://futureboy.us/fsp/frink.fsp?fromVal=2%5E94+inches&toVal=lightyears), which can do this in one shot. Simply enter: From: 2^94 inches To: lightyears and you'll see the answer! Rich Brown richard.e.brown@dartware.com Dartware, LLC http://www.intermapper.com 66-7 Benning Street Telephone: 603-643-9600 West Lebanon, NH 03784-3407 Fax: 603-643-2289