Re: IPv4 v IPv6
On Saturday 22 June 2019 15:34:52 Andy Smith wrote:
> On Fri, Jun 21, 2019 at 10:01:47PM -0500, David Wright wrote:
> > On Wed 19 Jun 2019 at 04:23:15 (+1200), Richard Hector wrote:
> > > On 19/06/19 4:12 AM, David Wright wrote:
> > > > On Mon 17 Jun 2019 at 10:38:27 (-0400), Gene Heskett wrote:
> > > >> But that opens yet another container of worms. If I arbitrarily
> > > >> assign ipv6 local addresses, and later, ipv6 shows up at my
> > > >> side of the router, what if I have an address clash with
> > > >> someone on a satellite circuit in Ulan Bator. How is that
> > > >> resolved, by unroutable address blocks such as 192.168.xx.xx is
> > > >> now?
> > > >
> > > > Seems a good reason not to bother setting up ipv6 local
> > > > addresses until we (you and I) understand it and ever see ipv6
> > > > on this side of the modem. I'm not holding my breath.
> > >
> > > If you never try setting it up, when do you expect to understand
> > > it? And I see IPv6 on my side of the modem; I suspect many others
> > > do too. I expect you'll get it sooner or later.
> >
> > What's more relevant to me is not when IPv6 is made availble to me,
> > but when IPv4 is withdrawn. Until then, I have IPv6 disabled in the
> > router.
>
> This is not quite the case. Here is why:
>
> IPv4 is almost entirely exhausted. In some regions it is already
> exhausted. New businesses entering the marketplace who want to
> advertise services on the Internet will need to either buy IPv4 on
> the auction market or else live behind something called "Carrier
> Grade NAT" (CGNAT).
>
> CGNAT can be in a couple of different configurations but the most
> common are as follows:
>
> - NAT444
>
> Three networks of IPv4:
>
> a) Customer's own private (RFC1918) IPv4 network.
>
> b) Provider's own public IPv4 network, but a much smaller number
> than the sum of customer networks.
>
> c) The public IPv4 Internet.
>
> - DS-Lite
>
> Two networks of IPv4 with an IPv6 core:
>
> a) Customer's own private (RFC1918) IPv4 network.
>
> b) Provider's IPv6 core.
>
> c) The public IPv4 Internet.
>
> Now probably if you aren't already behind a NAT444 you're not going
> to be put behind one, but it could happen to anyone at this point if
> they switch ISPs.
>
> So let's say you are an IPv4 hold-out who visits a small business's
> site who can't afford to buy highly valuable IPv4 addresses of their
> own¹. They are very possibly going to be behind a NAT444.
>
> If you also are behind a NAT444 then that's 6 layers of NAT that
> every packet traverses!
>
> CGNAT devices are really expensive and not a great solution. They
> have to hold a lot of state and any protocol that uses lots of ports
> can run them out of their per-IP state limits. As the end users
> either side don't have administrative control of the NAT in the
> middle, it is not possible without provider assistance to set up
> permanent mappings i.e. to set up servers that permanently hold an
> IP;port pair.
>
> NAT hampers the ability of end-to-end communication on the Internet.
>
> The good news is that there is a very easy fix. Just start using
> IPv6. There is no shortage of IPv6, so no reason why the newcomer
> sites can't serve on v6 immediately, and if you view on v6 then you
> side-step this entire CGNAT apparatus.
>
> Now, in the North American and European market, outside of cellular
> networks, it is still rare to end up behind a CGNAT. In the Asian
> markets a lot of people are behind CGNAT because they ran out of v4
> a long time ago. It's coming to us in Europe and North America too.
>
> That is why the stance that, "I have IPv4 so I don't need to do
> anything" is not completely correct: it's not urgent for much of the
> world at present, but we will get into a situation where either one
> or both sides of a given IP conversation are behind multiple layers
> of NAT that they don't control, and that's bad.
>
> It is essential though that ISPs turn on v6 and end users use it
> without even knowing. That's the only way this gets done.
>
> So I would say that most of the onus is on your ISP, but if they're
> doing their bit and providing IPv6 and your side isn't just working
> with it without you doing anything then that is a problem that
> should be looked into.
>
> If they aren't doing their bit and not providing v6 then I
> personally would be asking why and looking around for another
> provider, but it is the case that a lot of people are in a
> near-monopoly without real choice of ISP.
>
> Eventually the cost of CGNAT will force even those tardy ISPs to
> push out v6 to their subscribers, because there comes a point where
> that's cheaper than scaling the CGNAT.
>
> Cheers,
> Andy
>
This is likely true too. But as just a small town residential cable
customer, on a 10 Mb circuit, how can I apply pressure to my isp that
would speed up this deployment of ipv6? He no doubt has to buy the block
of ipv6 addresses before his dhcpd v6 can pass them out. Further proving
the TANSTAAFL principle. Lets say my local isp has 2k customers in this
town of about 7k. Whats a good guess at his cost on a per customer basis
to make it happen?
> ¹ To give you some idea of how valuable, I looked up what IPv4
> addresses are selling for today, and it's about $40k per /21. That
> means that my business's most valuable asset as of today is its
> IPv4 addresses. How will new businesses cope? I didn't have $40k
> when I started my business.
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>
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