back to article Facebook casts a hex with self-referential IPv6

IPv6 addresses aren't really supposed to spell out domain names, but Facebook has adopted an IPv6 addy that includes the characters "faceb00c." A quick DNS lookup of confirms this: the domain resolves to 2a03:2880:2130:cf05:face:b00c::1. Faceb00c. Get it? At The Reg's London office, we can’t agree on what we …

  1. Len


    We should probably consider ourselves lucky that the options are limited. Apart from things like :dead:, :beef:, :babe: and :taco: of course.

    1. Baggypants

      Re: Lucky

      you forgot :fa:cade

    2. Deltics

      Re: Lucky

      :taco: ? ... I don't think so

      1. Anonymous Coward
        Anonymous Coward

        Re: Lucky

        Maybe he thought it was hexatriacontadecimal (base 36)

  2. John Sager

    Well, they own the use of the addresses

    I noticed this a while back when trying to analyse some traffic anomalies on my home network. If they want to use some of the host part of their v6 addresses in that way then why not? Nice of them to label their addresses like that so we don't need to do reverse lookups. Of course, bad boys could emulate to mislead, but only geeks & network engineers look at v6 addresses anyway.

  3. Henry Wertz 1 Gold badge

    I'd like some dead beef

    I'd put some dead beef in my address, personally. Or c0ffee.

    1. Anonymous Coward
      Anonymous Coward

      Re: I'd like some dead beef

      On one of my OpenVPN connections years ago, I recall using a hardcoded MAC address of c0:ff:ee:ad:d1:c7 to ensure a consistent IP address.

  4. Anonymous Coward
    Anonymous Coward

    The face:b00c subnet…

    … is not new, it was mentioned in RFC5514.

  5. ZeroSum

    Why isn't theregister available over IPv6?

    You use a CDN (CloudFlare) that supports IPv6.

    1. Anonymous Coward

      Re: Why isn't theregister available over IPv6?

      You can't spell "The Register" or "El Reg" in hexadecimal in a way that's easy for people to recognise.

      I mean, who wants to try and work out 2001:0db8:5468:6520:5265:6769:7374:6572 or 2001:0db8::456c:2052:6567?

    2. Kevin McMurtrie Silver badge

      Re: Why isn't theregister available over IPv6?

      CloudFlare is self-proclaimed bulletproof service provider. That really puts a dent in connectivity and reliability rankings.

  6. Anonymous Coward
    Anonymous Coward

    I think I'll use a55 in my future IPv6 addresses.

    1. David 132 Silver badge

      I think I'll use a55 in my future IPv6 addresses.

      Oh dear, are we unleashing our inner 8-year-olds via the medium of IPv6 addresses? Back in my day it was 7-segment Casio calculator displays.

      Bagsie I get 5537:8008, 'cos it looks rude upside down as any fule kno. Also, teacher smells. Nerr.

      1. Norm DePlume
        Paris Hilton

        Sounds like a challenge

        Admittedly a bit difficult to cram into IPv6 addresses:-

        bedded 10c0 c1ass1e55 d011faced babe

        0ff10aded 5eed f100d

    2. Andy Miller

      A55 ?

      Are you in north Wales?

  7. Daniel B.

    Old news

    I had already noticed this on Sunday. I found out that was resolving to:


    IPv6 "vanity IPs" are fun. I've seen at least :b00b:babe:cafe, the ever present :dead:beef, :b00b:cafe among other funny spellings.

    I'm probably going to set up :b00b:135 in the near future...

  8. Mike 125


    I voted Sad, but was secretly thinking Cool.

    1. VinceH

      Re: Voting

      That's why there was a 'both' option!

      (Which was my vote)

  9. kpanchev

    I think it's the same reason people use custom car registration numbers - to compensate for other shortcomings...

  10. gnarlymarley

    Where is the news here? Facebook did this back in 2011 when they were based out of the US, before they moved to Ireland. pointed to 2620:0:1c18:0:face:b00c::, pointed to 2620:0:1c18:0:face:b00c:0:3, and pointed to 2620:0:1c18:0:face:b00c:0:1. Facebook also has been using the Ireland IPv6 range since around 2012 (2a03:2880:10:cf01:face:b00c:0:4, 2a03:2880:10:1f02:face:b00c:0:27, 2a03:2880:10:6f01:face:b00c:0:2, and such).

  11. WatfordJC

    It's not much different to me using ::80:0 through ::80:FFFF (currently up to ::80:c) for my Web sites, with ::8080:x, ::443:x, ::4443:x, ::8081:x, and ::8008:x reserved for future use.

    If you're not using SLAAC, and are running services on different IPv6 IPs, you may need to store IPv6 addresses in your short term memory. If the first 64 bits are in your long-term memory, and the last 64 bits aren't completely random, they are easier to remember.

    I have a ULA ::/48 (including four ::/64s) and three public ::/64s in my long-term memory.

    I could use ::c00c:1e:: if I wanted, just like The Register could use ::e1:12e9::, but what is the point if it just means having to remember even more in your long-term memory (going from 64 bits to 96 bits). Unless you're working on the servers, IP addresses (whether IPv4 or IPv6) are mostly hidden thanks to DNS.

    Something perhaps more newsworthy IPv6-related is that has enabled IPv6 support in the last month or so, so those of us with IPv6 can no longer rely on it to find out what our IPv4 IP address is.

    1. Daniel B.

      SLAAC and fixed IP

      Solaris 10 allows you to add a "token" to your IPv6 config, which will be used during SLAAC. So you set up:

      ifconfig e1000p0 inet6 token ::b00b:babe:cafe/64

      and you'll get that addy even if you are using SLAAC. :)

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