On Oct 5, 2009, at 11:34 AM, Wayne E. Bouchard wrote:
On Mon, Oct 05, 2009 at 08:18:23PM +0200, Jens Link wrote:
"Brian Johnson" <bjohnson@drtel.com> writes:
So a customer with a single PC hooked up to their broad-band connection would be given 2^64 addresses?
I realize that this is future proofing, but OMG! That?s the IPv4 Internet^2 for a single device!
Most people will have more than one device. And there is no NAT as you know it from IPv4 (and hopefully there never will be. I had to troubleshoot a NAT related problem today and it wasn't fun.[1])
And I want more than one network I want to have a firewall between my fridge and my file server.
Am I still seeing/reading/understanding this correctly?
RFC 3177 suggest a /48.
Forget about IPv4 when assigning IPv6 Networks to customers. Think big an take a one size fits all(most) customers approach. Assign a /48 or / 56 to your customers and they will never ask you about additional IPs again. This make Documentation relay easy. ;-)
cheers
Jens
Am I the only one that finds this problematic? I mean, the whole point of moving to a 128 bit address was to ensure that we would never again have a problem of address depletion. Now I'm not saying that this puts us anywhere in that boat (yet) but isn't saying "oh, lets just put a /64 on every interface" pretty well ignoring the lessons of the last 20 years? Surely a /96 or even a /112 would have been just as good.
Nope.... It really isn't. If we wanted to do that, then, IPv6 would probably have 64-bit addressing, instead of 128-bit, and, you'd have 32 bits of carrier, 16 bits of end- site, 8 bits of subnet and 8 bits of host (or something approximating that). Part of the reason that 128 bits was chosen (64 bits is FAR more than enough) was that it allowed for 64 bits of stateless auto-configuration (IEEE was already pushing EUI-64) within each network and still provided more than enough network numbers.
Lets think longer term... IPv4 is several decades old now and still in use. If IPv6 lasts another 50 years before someone decides that it needs a redo, with current practices, what will things look like?
OK.
Consider the population at that point and consider the number of interfaces as more and more devices become IP enabled. "wireless" devices have their own issues to content with (spectrum being perhaps the biggest limiter) so wired devices will always be around. That
The planet's sustainable population is not likely to exceed 10 billion. (However, current growth is approximately 80 million per year, so, our current 6 billion + 80 million * 50 = 4 billion still puts us at around 10 billion, so, it should be a safe number even if we throw sustainability out the window). IPv6 offers us 32 bits of provider units == 4 billion providers. Each provider can serve 65,536 customer units which gives us the ability to support 281,474,976,710,656, or, about 281 trillion customers. Each customer unit gets 65,536 subnets to do with as they like and they still have 64 bits on each subnet.
means physical interfaces and probably multiple LANs in each residence. I can see where each device may want its own LAN and will talk to components of itself using IP internally, perhaps even having a valid reason for having these individual components publically addressable.
It's OK. We can do it. We will still have addresses to spare even in 50 years, even with that.
Like I said, I'm not necessarily saying we're going to find ourselves in that boat again but it does seem as though more thought is required. (And yes, I fully realize the magnitude of 2^64. I also fully realize how quickly inexhaustable resources become rationable.)
Well... There is a safety valve. We are only issuing from 1/8th of the current address space at this time. If we run that out before we expect to and it becomes clear that there is a need to allocate differently, we can begin doing that from the next 1/8th without any real changes to the protocol or router software. Really, it's OK. Owen