Assigning IPv6 /48's to CPE's?

Rick Astley jnanog at
Mon Dec 31 08:25:01 UTC 2007

I see there is a long thread on IPv6 address assignment going, and I
apologize that I did not read all of it, but I still have some unanswered

I believe someone posted the ARIN recommendation that carriers assign out
/64's and /56's, and in a few limited cases, /48.

I can understand corporations getting more than a /64 for their needs, but
certainly this does not mean residential ISP subscribers, right?

I can understand the need for /64's because the next 64 bits are for the
client address, but there seems to be this idea that one and only one node
may use a whole /64. So in the case of Joe, the residential DSL subscriber
who has 50,000 PCs, TiVo's,  microwaves, and nanobots that all need unique
routable IP addresses, what is to stop him from assigning them unique client
ID's (last 64 bits) under the same /64? We can let Joe put in some switches,
and if that isn't enough he should consider upgrading from his $35/month DSL
or $10/month dial up anyway.

My next question is that there is this idea that there will be no NAT in the
IPv6 world. Some companies have old IPv4 only software, some companies have
branch offices using the same software on different networks, and some like
the added security NAT provides.

There are also serious privacy concerns with having a MAC address within an
IP address. Aside from opening the doors to websites to share information on
specific users, lack of NAT also means the information they have is more
detailed in households where separate residents use different computers. I
can become an IPv4 stranger to websites once a week by deleting cookies,
IPv6 means they can profile exactly what I do over periods of years from
work, home, starbucks, it doesn't matter. I don't see NAT going away any
time soon.
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