Re: v6 subnet size for DSL & leased line customers
--- nanog@85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org wrote: From: Mark Smith <nanog@85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org> I'd also be interested to know what you'd *want* if you were asked how you'd like to structure IPv6 addressing, if you didn't have any history of having to be conservative with IPv4 addressing. IOW, imagine IPv4 didn't exist, and therefore your thinking about IPv6 isn't influenced by your history with IPv4. -------------------------------------------------------------------------- If I wasn't worried about routing table size (you said "if you didn't have any history...imagine IPv4 didn't exist") I wouldn't give household and SOHO networks billions of addresses. scott
On Fri, 21 Dec 2007, Scott Weeks wrote:
If I wasn't worried about routing table size (you said "if you didn't have any history...imagine IPv4 didn't exist") I wouldn't give household and SOHO networks billions of addresses.
Well since it looks like it takes about 20-30 years to get a new version of the IP protocol deployed we have to look way ahead. Now I think there is a chance that full nanotech could deploy in the next 20 years so the protocol should probably be designed with that possibility in mind. Now according to an article on Utility Fog [1] one idea is that most of the household objects around us could be replaced with small nanotech robot. Each might weigh 20 micrograms which means 50,000 per gram or 50 million per kilogram. Non moving CPUs would probably be smaller. So my house may have a couple of tonnes of them scattered around in thousands of objects (chairs, screens, door handles, fly screens, sensors) with between a few hundred to a few billion bots in each. Yeah sure it's science fiction now but it's fairly possible that it could be the situation in say 2030 and IPv6 is probably good enough to handle it. If we'd let you design a protocol that didn't support billions of SOHO addresses then around 2020 we'd be madly deploying IPv7. However in the shorter term nobody has billions of IPs and most people don't have thousands of networks. My understanding is that the main idea with the /48 is that everybody smaller than a provider, government or a Fortune 500 company will just get one and no further paperwork will be required. Dropping it to a /56 means that a certain percentage of your customers are going to have to negotiate, fill out paperwork and pay extra for their /48 which is going to add costs all around. [1] http://www.kurzweilai.net/meme/frame.html?main=/articles/art0220.html -- Simon J. Lyall | Very Busy | Web: http://www.darkmere.gen.nz/ "To stay awake all night adds a day to your life" - Stilgar | eMT.
On Sat, 22 Dec 2007, Randy Bush wrote:
logic chains which begin with
Now I think there is a chance that
may not be the best way to do engineering. there is a 'chance that' just about anything.
Sure, the Sun could explode tomorrow and all these IPv6 people will have wasted their lives. However the scenario is a common one and the timetable is well within the time period when IPv6 will be the main network technology (say 2015 - 2035+) so it should have been taken into account and judging on the fact that IPv6 *does* support billions of nodes and thousands of networks to every end site I guess it probably was. Making engineering decisions on the basis of "there is no chance" that is risky too, especially looking 40+ years into the future. -- Simon J. Lyall | Very Busy | Web: http://www.darkmere.gen.nz/ "To stay awake all night adds a day to your life" - Stilgar | eMT.
simon, there are a million chances. and we are notoriously bad at predicting any of them more than a year or so out. randy
In a message written on Sat, Dec 22, 2007 at 12:29:54PM +0900, Randy Bush wrote:
simon, there are a million chances. and we are notoriously bad at predicting any of them more than a year or so out.
Perhaps the take-away is that we shouldn't try to design protocols that last for 30-100 years, but rather design frameworks that make deploying updates easier? Naw. -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/ Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org
On Sat, 22 Dec 2007 12:29:54 +0900 Randy Bush <randy@psg.com> wrote:
simon, there are a million chances. and we are notoriously bad at predicting any of them more than a year or so out.
In general, you're right. But we have ~60 years of experience teaching us that *every* successful computer architecture runs out of address space. I see no reason to think that today's models for home address space will be the exception (unless, of course, IPv6 is unsuccessful, but in that case it doesn't matter much what we do for allocation policy unless our actions are sufficiently stupid to cause the failure). --Steve Bellovin, http://www.cs.columbia.edu/~smb
participants (5)
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Leo Bicknell -
Randy Bush -
Scott Weeks -
Simon Lyall -
Steven M. Bellovin