[AusNOG] My Predictions for the ISP Industry

[Mark Newton]

On Fri, Mar 16, 2012 at 03:32:14PM +1100, Mattia Rossi wrote:

 > Here I have a question:
 > To me it seems that Paul is using 6to4 on the CPE.

Yes.  Trap for young players:  A lot of the CPE that has historically
been on the market and sold in boxes with "IPv6 Ready" stamped on 
the side doesn't do native IPv6 on the WAN side.

It does SLAAC on the LAN side, and slurps up any IPv6 packets it
sees and 6to4's them.

 > 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.

 > 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)

 > I'm a bit surprised that this actually works...

Aren't we all!

  - mark