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If you know anything about IPv6, you know that it expands the number of possible IP addresses to an unimaginably large scale. This relieves the pressing shortage of IP addresses being faced today in IPv4, so that there will be addresses available for all the new web sites, printers, cars and light bulbs that will need them.

IPv6 does this trick by using nice, big 128 bit addresses which are noted in hexadecimal.  And the hexadecimal is where some fun comes in.

I’m not kidding: Fun!  The fun is that hexadecimal addresses include, as you know, A,B,C,D,E, and F in addition to numerics. So, now those with a technical bent can actually start to spell some things even in the numeric addresses. It was inevitable that some clever people would combine the hex notation of IPv6 with the Internet tradition of “leetspeak.” (Leets are a kind of cute code, as you probably know, where you can replace letters with numbers that look similar. O becomes zero, L or T become 7, S becomes 5, G becomes 6, etc. Hence the name L33T (or more correctly 1337). Well, with ABCDEF in addition to the numbers, there are some fun possibilities for IP addresses.  Letters? Leets? Imagine the possibilities for clever numeric addresses!)

We've already seen a couple in the wild:

Facebook’s IPv6 address:

face:b00c (“facebooc”)

Full address:  2620:0:1cfe:face:b00c::3

A Cisco IPv6 test address:

c:15c0:d06:f00d (“cisco dogfood” as in “test your own dogfood”)

Full address:  2001:420:80:1:c:15c0:d06:f00d

Of course, the only people who will ever see these addresses are people who speak in hextets, which makes them all the more fun. (Most people will never see these addresses, because IPv6 is nicely invisible to users and you'll still type facebook.com to get the Facebook, for example).

We haven't seen any others yet, but Cisco's Phil Remaker suggests that perhaps Starbucks.com could use CAFE or the National Cattlemen’s Association would use BEEF or that the LA County Coroner’s Office (and its gift shop) could use DEAD (if My Chemical Romance or the Grateful Dead's dead.net don't grab it first).

Underneath this humor is a serious fact: The world is running out of IPv4 addresses, and the world’s technology companies and organizations are working together on the upcoming World IPv6 day on June 8th to test IPv6 end to end in action.  You’ll be reading quite a lot more about the benefits and lore of IPv6 in coming days and weeks.

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1 Comments.


  1. Phillip Remaker
    Phillip Remaker

    There is a thread at http://news.ycombinator.com/item?id=2631608 which observes some interesting IPv6 addresses in the wild.

    Some of my favorites:
    BBC: 2001:4b10:bbc::2
    Sprint.net: 2600:: (Yes, all zeroes is a valid host address)

    I think that icanhazcheezburger.com should use 101:ca75, but they remain steadfastly IPv4. I can has IPv6?

       1 like

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