Sunday, 24 October 2010

Broken IPv6

OK, hotel wifi assigns an IPv6 address - woohoo!

Except it is:-

(a) a 2002:: address which is a tad silly
(b) not actually working


I seriously doubt the hotel will have any clue if I complain...

P.S. I've emailed guest relations. I wonder how daft their reply will be. I'll post a follow up.


  1. I'm guessing they don't actually know their router is dishing out IPv6 addresses, I'm also guessing the company who installed the WIFI doesn't know the router is dishing out IPv6 addresses!

  2. I am actually thinking it may be some other device on the WiFi doing RA based on its DHCP allocated address. Which would be why it cant route.

    That's an interesting problem. Not specially new to IPv6 as the same could be done by adding a DHCP server to the LAN. Only two DHCP servers would be more obvious.

  3. Hmm, are there any distros that will do IPv6 RA 'out the box' for some mad reason, as that could obviously cause chaos on a wider scale (imagine what would have happened if e.g. Windows XP ran a DHCP server by default). If not, then I wonder what on earth someone has set up and why - something attempting to do a 6-4 gateway perhaps?

  4. Yeh, I wonder. You would expect to see the filter broadcast user to user traffic or something.

    Of course they have not replied to either of my complaints!

  5. I never figured it out, but supposedly there is some weird combination of options under Windows Vista that will make it an rogue advertising zombie.

    I see that on other networks frequently and those hosts always seem to run Windows. For hints on how to deal with roue RAs: article by IPv6 Task Force Hawaii

  6. This is actually a bit nasty security-wise, isn't it? What is to stop someone advertising their own IPv6 gateway based on their DHCP-assigned address, and actually routing the traffic? Other users of the WLAN would get what appears to be an enhanced service ('it does IPv6 now') but their traffic would be getting read by a third party.

  7. No worse than any other public WiFi network - with ARP poisoning you can easily achieve an identical effect with IPv4, not to mention simply sniffing the traffic straight off the air in the case of wifi...

  8. Same issues as rouge DHCP servers and ARP spoofing.

  9. Did you know you can IPv6ify your blog?: