
Comcast Activates First Users With IPv6 Native Dual Stack Over DOCSIS - there
http://blog.comcast.com/2011/01/comcast-activates-first-users-with-ipv6-native-dual-stack-over-docsis.html
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allenbrunson
Okay, if we're really starting to do this, then I guess I have to figure out
how to upgrade all my code to deal with IPV6. I use the BSD sockets interface
for most things.

I assume we'll be living in a mixed IPV4/IPV6 world for awhile. Who's got a
tutorial for making a connection to a host using IPV6 if available, but
falling back to IPV4 if it isn't?

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dfox
See getaddrinfo(3) man page, that should be almost all you want. Making code
mixed v4/v6 that way actually seems easier than v4-only solution with
gethostbyname(3) and building struct sockaddr manually.

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zitterbewegung
This is great :-) I hope more Internet Service Providers follow suit! I'm
actually glad for once that I have comcast.

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ballen
Odd I've had IPv6 on Comcast in the Northern NM area for at least the last
three months.

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Splines
You were probably on the 6RD IPv6 trials: <http://www.comcast6.net/faq.php>

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hcurtiss
18 quintillion . . . why?

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shkb
Well we ran out of 4 billion, and much of the world isn't really online yet.
Then factor in having a laptop, a smartphone, gaming console, HPTC, etc.
There's more servers and infrastructure too. It's not that much overkill
either, only 4x more bits.

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jmillikin
The article states that 18 quintillion is being allocated to _each customer_ ,
which does seem a bit excessive.

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bodyfour
(recycling an post I just made on the same topic on /.)

In short:

1\. an ISP would be allocated a /32. This sure sounds like a lot (2^96
addresses!) but it only is the same burden as a _single address_ in IPv4! Even
if there were millions of ISPs, this would be no burden on the address space
at all. We'd lose the ability to route before we'd exhaust the addresses.

2\. Then an ISP can assign a /64 to customers. Again, this sounds like a bit
much, but its a tiny fraction of their space. Even if the ISP had a billion
customers like this they would be completely fine.

3\. This leaves a huge amount of space available for the customer to segment
however they please.

4\. In the simplest case you'd use a single network with 48-bits taken up by
the ethernet MAC address (removing the need to do any address assignment!)
Alternatively you could segment the space a bit more and run a transnational
corporation's network inside the /64. Up to you!

2^128 is a really REALLY big number. No reason not to spread out a little bit.

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swolchok
Yeah, and 2^32 computers should be enough for anybody. ;)

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pyre
I know you're joking, but I think the point is that the numbers are so large
that we really don't have the tech right now to exhaust the space. I remember
hearing in the past that 2^128 is close to or more than the number of
molecules (or was it atoms?) in the known universe. We're not at the point
where we can assign an address to every atom and make use of it... yet at
least.

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jtchang
Is anyone else surprised that Comcast has actually gotten off their ass and
decided to start going ahead with this? I guess my expectation was that
Verizon would be headlining IPv6 and not Comcast.

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ronnier
Comcast also caps usage to 250GB per month.

[http://customer.comcast.com/Pages/FAQViewer.aspx?Guid=3ca542...](http://customer.comcast.com/Pages/FAQViewer.aspx?Guid=3ca5420c-75b0-439c-b8bd-16d89157c333&fss=250)

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gergles
FWIW, it's a softcap. I have several friends who have gone well over (we're
talking 1TB+) and haven't received the dreaded phone call.

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pquerna
FWIW, we hit 256gb, and we got a call, threatening if we passed it again in 6
months we would be banned from Comcast for 12 months. (Someone in the house
accidentally left a torrent sending for 3 weeks)

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travisp
Perhaps whether they call you after the limit depends on _why_ you went over
the limit. It should be easy to determine if the reason you went over is a
torrent (even if they can't figure out what torrent), video streaming, or
something else.

