My ISP to this day still doesn't have dual-stack. It makes a 6rd tunnel available to their users as a "beta" (for years). I find it mystifying to be honest. I know for a fact they have a nice modern facility and an expert head sysadmin. They even have a local fiber optic network. It makes no sense to me that they're clinging so tightly to IPv4.

What is the benefit to the ISP in supporting IPv6 to justify the extra cost of the support?

Some devices coming out now from Google, etc. are IPv6-only and do not support 6rd tunnels at all.

Possible further benefit, reaching India and China who certainly aren't issuing IPv4.

Hopefully the day comes when people can get static IPv6 addresses instead of a dynamic one behind an ISP NAT.

> Possible further benefit, reaching India and China who certainly aren't issuing IPv4.

This is important for servers, but not so much for consumers, IMHO. Sites in India and China are highly likely to be dual stacked, so v4 only users aren't likely to be missing any content at least currently. Although certainly missing access to v6 preferred peers. There's very few really v6only use cases out there yet, almost every consumer access network has some way to get to v4, there's too much v4 only content not to; even if the v4 access is much worse than v6, as it sometimes is.

> get static IPv6 addresses instead of a dynamic one behind an ISP NAT.

Some UK ISPs give out /48s (cough Sky) but with dynamic allocation. So you reboot your router and every single IPv6 device on your network needs to re-address. Makes routing/port forwarding a PITA and nearly impossible using IPv6.

Even if it was static changing the ISP will result in a new public range, meaning an internal re number, unless you use NAT, in which case you may as well use ipv4 and nat.

If you have two ISPs (say a backup 5G) then you have to renumber every time the main goes down. If you want to load balance you’re screwed, unless of course you use nat.

Residential ISPs won’t allow you to bgp peer your own /48

> Even if it was static changing the ISP will result in a new public range, meaning an internal re number, unless you use NAT, in which case you may as well use ipv4 and nat.

Kind of: if you use IPv6's ULA (fc00/7 [1]), then you can have a NAT-like translation layer using NPTv6 [2]. The advantage of NTPv6 over NAT44 is that you get an entire prefix to play with instead of a single IP on your router's WAN interface.

If you wish to have multiple services (web, SSH, Minecraft), then with IPv4 hole punching you can only have one server on the default port and the second system with the same service needs to be on a different port. With IPv6/NPTv6 you can have each service on a different IPv6 address and live on its default port.

You also have the flexibility of either only allowing one particular port in for that service/IPv6 address, or just allowing all traffic in without any firewalling/filtering.

So NPTv6 is no worse than NAT44 in the simple cases, but also has extra functionality over it.

[1] https://en.wikipedia.org/wiki/Unique_local_address

[2] https://en.wikipedia.org/wiki/IPv6-to-IPv6_Network_Prefix_Tr...

> Even if it was static changing the ISP will result in a new public range

I bet most people change ISPs with a frequency that's a fraction of the frequency they reboot their routers.

In any case, only a few devices in most households require static public IPs (only the ones you connect to from the outside directly). If you put those in DNS, all you need to do is change their AAAA records.

For internal comms, IPv6s in the link- or site-local ranges are better anyway.

I guess that's a good point, even if my ISP did have IP V6, I'd need to get a static from that too. Bet they'd want me to pay extra for that one on top of the V4 cost.

Huh? I'm only able to get a single /64 with Sky. If I enable PD then I get nothing. Perhaps this is the fault of the Unifi Dream Machine's poor IPv6 support... maybe I should take another look?

I thought the same with my ISP, but it turned out it was pfSense who didn't do the right thing or something. Switched to OpenWRT and I got a /56 right away.

>Some devices coming out now from Google, etc. are IPv6-only and do not support 6rd tunnels at all.

I find this very, very hard to believe. I haven't found anything online. Can you give me some pointers?

>Possible further benefit, reaching India and China who certainly aren't issuing IPv4.

All Indian and Chinese websites have ipv4 addresses in case I wanted to reach them.

I think people should come to terms to the fact that everybody is moving to cgnat and the world is not falling apart as they said it would.

Most mesh devices (not wifi), i.e. thread/openthread devices that use 6LowPAN are IPv6 only. They're often based on microcontrollers with limited resources, so dont even support TCP, only UDP. Many smart meters also use this same set of technologies (IPv6/6LowPAN/UDP/CoAP/etc) which is my own area of expertise, but the Google (and Amazon) devices also use these.

> people should come to terms to the fact that everybody is moving to cgnat and the world is not falling apart as they said it would.

As someone who's behind CG-NAT, I agree that the world is not falling apart. It is, however, very inconvenient.

The IPv4 Internet has more fluctuation in latency - I imagine it gets worse in periods when many more connections are having to go through the ISP's CG-NAT router, and/or when a lot more volume of data is going through that same bottleneck. It's not the end of the world, but it's not ideal.

On top of that, my IPv4 traffic is bundled together with a cohort of cusotmers whose Internet behaviours I know nothing and have no control about. This affects my reputation on things like CAPTCHAs and other forms of access control. It's not the end of the world, but it's not ideal.

I can't get into my own network from an IPv4-only external network without resorting to routing contortionism. It's not the end of the world, but it's not ideal.

CG-NAT requires expensive and power-hungry equipment, which in turn means more maintenance, more complex infrastructures, more equipment failure and replacement and increased energy usage.

It's not the end of the world.

But it may well be contributing to it.

> >Some devices coming out now from Google, etc. are IPv6-only and do not support 6rd tunnels at all.

> I find this very, very hard to believe. I haven't found anything online. Can you give me some pointers?

Google Wifi, Mercku M2, etc. have been reported as not having support for 6rd or 6to4.

It will take something absurdly massive like the iPhone to drop IPv4 to turn the tide. Look at how Apple's aggressive use of the iPhone has changed things. Right now it's their push for eSIM.

You don't need NAT, especially CGNAT.

They don't need to buy as expensive cgnat hardware if a greater proportion of traffic is ipv6. That's the rationale given by an up-and-coming ISP in Australia.

Still need CGNAT for Dual Stack - Lite. Or, a NAT for 464Xlat.

Video is by far the largest bandwidth hog that most people use, and both Google/Youtube and Netflix support IPv6 for streaming last time I checked. The more traffic that supports IPv6, both from the client- and server-end of things, the less horsepower that the CG-NAT boxes need for network processing (and for things like logging of connection mappings for mandated law enforcement purposes).

There is certainly an upfront cost of getting IPv6 going for a 'legacy' ISP, but once the infrastructure is there it can reduce the ongoing costs of CG-NAT (because IPv6 will just be part of the fixed costs that you need to be an ISP).

Which ISP? (am curious as an Australian)

Aussie Broadband

It just works and IPv6 solves no problems while bringing many more. If address space was a problem, we d have switched when mobile phone started doubling the number of devices: but they can all have the same IP per tower and use NAT ...

Mobile providers are among the largest users of IPv6 for exactly that reason. You might even already use IPv6 on mobile without realizing it..

I too am waiting for Sonic Fiber to finally get native IPv6. Luckily, they finally started rolling it out in some cities.

> Why does Tesla announce 6x /48s instead of having a /32 of their own and handling their routing internally?

Probably the same reason they annouce /24s and not aggregated prefixes on v4 when they're contiguous. We can't tell from the he bgp tools, and I'm not going to look at other tools, but I'm guessing those /48s are distinct sites and are advertised differently (or maybe one is used as anycast, the others being distinct sites). Theoretically disconnected sites could each have their own AS, but it's very common for an organization to use a single AS globally, and only advertise locally served addresses at each site/BGP session.

> Home networks are doomed to by v4 forever

Why? I've had dual-stack at home for many years, and I can hit sites via IPv6-only: way back when I blocked Facebook connectivity for privacy reasons, but at some point I noticed I started getting those little FB icons again that came directly from their servers. Turns out that I was hitting them via IPv6 and had to update my (DNS filtering) rules to block AAAA records as well.

Even my not-very-new Brother HL-L2360 supports IPv6, and has both a fe80 link-local address, and a 'proper' address that it got via a prefix advertisement from my Asus router.

Most IoT devices run Linux under the hood and get IPv6 support 'for free'.

Happily running dual stack, with a routed /48 (further subdivided between work, IoT, management and trusted VLAN's). It's crazy though that the 2nd biggest ISP in the country, Virgin (DOCSIS cable) STILL haven't rolled out IPv6; say what you will about BT/OpenReach, but they got IPv6 to market in the UK pretty damn fast.

> ping from Earth to Mercury is 230,000ms at best.

Not really your point I know, but I was curious about this so I looked it up. The closest Earth and Mercury get is 77.3 million km[1], which is 515.7 seconds round-trip (ping) at the speed of light.

[1] https://nssdc.gsfc.nasa.gov/planetary/factsheet/mercuryfact....