[AusNOG] My Predictions for the ISP Industry

[Mattia Rossi]

>
>   >  This means that the
>   >  CPE is creating a 6to4 prefix out of it's public facing IPv4 address,
>   >  which is then used to distribute v6 addresses to all his IPv6 devices in
>   >  the house.
>
> More or less.  Or some other prefix.  But yes.
>

Some other prefix? E.g. fc00::/7 ?

>   >  So far so good... but my question is: how do machines inside the house
>   >  handle addresses of the 2002::/16 prefix?
>
> When they're chatting among themselves, in all likelihood they
> don't use 2002::/16 at all, and use link-local addresses instead.
>
> (you see this on your LAN at home if you have any iOS devices
> such as AppleTV's or WiFi associations with your iPhone:  Run
> "ndp -a" on a Unix box and you'll see the link local addresses
> for the iOS systems showing up as neighbors.  If your Unix box
> happens to be a Mac, you'll even see them with .local mDNS names)
>

So there's some form of NAT happening (1:1 NAT)? Link local in the LAN, 
and if the destination is outside the LAN, the CPE keeps the 64 bit host 
part of the source address intact, rewrites the 64 bit prefix part to 
the 6to4 prefix, and off they go? Interesting...

Btw. mDNS is a real lifesaver when it comes to IPv6 and you don't have 
an authoritative DNS server for your LAN and possibly a real (or fake) 
domainname to use within it.

>   >  I'm a bit surprised that this actually works...
>
> Aren't we all!
>

:-)