[AusNOG] My Predictions for the ISP Industry

[Mark Newton]

On Fri, Mar 16, 2012 at 04:01:21PM +1100, Mattia Rossi wrote:

 > 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...

No;  just multiple addresses on each interface.

Every interface comes up with a link local address "for free."  
And SLAAC is used to set up one or more unicast global addresses.
DNS responses and host specific policies which decide which ones
get used.

 > 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.

You probably have an authoritative DNS server inside your CPE,
which is handed out in DHCP responses.

A smart CPE vendor would sniff the traffic running through the
CPE's built-in switch for local DNS, WINS, mDNS, etc and use 
the data contained therein to construct DNS zone data for the
house's internal network dynamically, so that the end user
can do a DNS lookup on "mypc" or "TIVO" or "Dishlex-M238D" and
expect it to work, and have reverse mappings set up too.

Not sure if any CPE actually does that, but it seems to me that
it's the right answer.  In a suitably authenticated world,
an ISP could even delegate customer-specific zones to the 
DNS server in the CPE...

That's kinda the only way I can see IPv6 reverse mappings ever
working properly in a dynamic SLAAC-configured world, in any
case.


  - mark