6to4 public anycast relay considered a bad think (was Re: 6to4 connectivity test)

[Alain Durand <alain_durand@cable.comcast.com>]

Open relays are usually a bad think. Public anycast open relays are just
worse. Even if you are not concerned about security issues, there are
problems: you never know where they are, if they will be there tomorrow, if
they are on the other side of the planet, if the bandwidth is reasonable,
etc..

Essentially, expecting to get a functioning 6to4 relay is expecting a free
lunch. Who is going to pay for it?

IMHO, the entire model is broken.

   - Alain.


On 2/1/08 2:37 PM, "james woodyatt" <jhw@apple.com> wrote:

> A standard method of discovering whether the 6to4 relay at the
> anycast address is functioning properly would be a fine idea.
> 
> At the moment, some very large ISP's are now hindering transition to
> IPv6 by forwarding 6to4 packets to relays that are black-holing them
> rather than forwarding them.  (This was not the case when AirPort
> Extreme shipped.)  These ISP's have no plans to deploy 6to4 relays in
> their own IPv6-capable networks, nor do they have any plan to forward
> 6to4 traffic to relays that will carry it for them.  This is making
> some large content providers *remove* their AAAA records when they
> discover that customers behind 6to4 routers, e.g. AirPort Extreme,
> are unable to receive service because their applications do not fall
> back to IPv4 when IPv6 connectivity is broken.
> 
> Search the Apple discussion boards for IPv6, and you will see that a
> lot of people are turning off IPv6 entirely on their computers to
> work around the connectivity issues involved here.
> 
> 
> --
> james woodyatt <jhw@apple.com>
> member of technical staff, communications engineering
> 
> 
>