[jdw64]

I made my homepage (www.makonea.com) support IPv6 too, but the number of people actually using it is much smaller than I expected. Is IPv6 really that widely used? I'm supporting both because I heard it's good to support both, but I'm not sure what the actual benefit is. Sometimes, when behind Cloudflare, I think even if someone connects via IPv6, it ends up coming through as IPv4

[BadBadJellyBean]

It's good to support it to resolve the chicken egg problem. If no service supports it, there is no sense in deploying it to the customers and the other way around.

Also you made the life better of people who have DS lite. They only get a public IPv6 and all their IPv4 traffic goes through a CGNAT.

[reddalo]

For people like me: DS Lite stands for "IPv6 dual-stack lite". My mind went directly to Nintendo and I was confused.

[ash]

Unfortunately, individual actions would never be enough to solve the IPv6 chicken and egg problem. See djb's "IPv6 mess" article:

https://cr.yp.to/djbdns/ipv6mess.html

Yes, it is old, many examples are outdated, but the main points still hold. Decades later his suggestions for making IPv6 succeed are still not implemented.

[tormeh]

This stuff is obvious now, but I think back then this was probably quite clever.

[BadBadJellyBean]

It's not a lot but it's better to be part of the solution than the problem even if it is an insignificant contribution.

[commandersaki]

Which is which?

[fc417fc802]

For client server web browsing what's the downside of CGNAT? I'd understand if we were talking about self hosting a service from home but for typical consumer usage?

[gucci-on-fleek]

1. Peer-to-peer networking won't usually work correctly. And quite a bit of software uses P2P networking these days---BitTorrent, Zoom/Teams (via WebRTC), Tailscale, PlayStation/Xbox multiplayer, etc. Most of these services have automatic fallbacks when P2P networking doesn't work, but these fallbacks are usually slower and less reliable.

2. Most websites assume that 1 IPv4 address==1 household, so you'll often run into rate limits. Or even worse, you might be blocked entirely if your CGNAT neighbours are spammers or otherwise breaking website rules.

[fc417fc802]

While true, neither of those are relevant in context (and I even explicitly acknowledged your first bullet in my comment above). It was suggested that a website operator deploying IPv6 would somehow improve the end user experience by virtue of avoiding CGNAT and I was questioning that. I do of course appreciate that going via CGNAT to a clueless operator that eagerly adds IPv4 bans can be problematic but that's more a question of why you as a consumer might want IPv6 connectivity not why a service provider would want to deploy it.

[gucci-on-fleek]

> While true, neither of those are relevant in context (and I even explicitly acknowledged your first bullet in my comment above).

Yeah, I just mentioned that because P2P networking is used a lot more than most people think these days, since even things like Zoom that look like typical client–server web browsing actually use P2P networking internally.

> It was suggested that a website operator deploying IPv6 would somehow improve the end user experience by virtue of avoiding CGNAT and I was questioning that.

Reliability and latency will be marginally better with IPv6 than with CGNAT, but this is so minor that I doubt that most people will notice this. And many CGNATs will RST connections that last too long, but most protocols have some sort of automatic retry/reconnect built in, so this shouldn't cause issues very often either.

IPv6 addresses are quite a bit cheaper than IPv4 addresses in most clouds, but since most servers still need to support IPv4, this doesn't help you directly. Supporting IPv6 means that others using the cheaper IPv6-only cloud services will be able to connect to your server, but this doesn't matter for consumer-only services.

So yeah, you're probably right that enabling IPv6 server-side won't have (m)any benefits.

> I do of course appreciate that going via CGNAT to a clueless operator that eagerly adds IPv4 bans can be problematic but that's more a question of why you as a consumer might want IPv6 connectivity not why a service provider would want to deploy it.

Being able to ban IP addresses without worrying about collateral damage is a pretty big benefit to the service provider though, for certain applications at least.

[inigyou]

If you're using a cloud you'll probably find it useful to have ipv6 on every server and ipv4 only on the front end gateway

[throw0101a]

> It was suggested that a website operator deploying IPv6 would somehow improve the end user experience by virtue of avoiding CGNAT and I was questioning that.

Non-legacy, newly formed ISPs have to spend a lot of money on either buying or leasing IPv4 address space, and even then if they grow they probably won't be able to keep up, and so have to deploy 100.64.0.0/10 to the WAN interface of CPEs and then buy a bunch of CG-NAT hardware.

The problems are on not entirely visible at the end-user side of things because of the Herculean efforts by ISPs.

IPv4-only services are thus externalizing the costs of connectivity to ISPs (especially newly formed ones).

[fc417fc802]

> externalizing the costs of connectivity to ISPs

Isn't that literally their raison d'être? Point taken that in aggregate it increases the costs of network operators but still that's got nothing to do with an individual instance of an individual user visiting an individual website.

[hdgvhicv]

1) my stateful firewall is going to break most of that anyway

2) if cg nat is as popular as people claim then they won’t be doing that as it’s not an edge case

[inigyou]

P2P protocols don't have much problem opening up a stateful firewall connection as you just have to send one packet out to open a known address and port.

I prefer to run scrapers behind CGNAT because websites can't ban it without causing collateral damage, which matters more to some than to others. The website probably has to put up a captcha. Which hurts its human traffic. Think about how much more traffic you could have if you didn't show everyone a captcha, and you might see that you should also be in favour of IPv6.

[throw0101a]

> 1) my stateful firewall is going to break most of that anyway

Your CPE is probably running UPnP IGD and/or PCP for hole punching of P2P services, and IGD/PCP can hole punch just as easily for IPv6.

> 2) if cg nat is as popular as people claim then they won’t be doing that as it’s not an edge case

It's not whether CG-NAT is an edge case or not, it's whether there are things that are completely impossible with it or not. Want to play with your friends on your Xbox/PS? Too bad, CG-NAT makes it completely impossible.

Why should we be happy with a technology that makes certain use cases impossible? On what planet is that a good thing?

[gucci-on-fleek]

> 1) my stateful firewall is going to break most of that anyway

Stateful firewalls and even regular NAT aren't much of an issue for P2P, but CGNAT is much more problematic [0].

> 2) if cg nat is as popular as people claim then they won’t be doing that as it’s not an edge case

You'd hope, but people tend to be pretty slow to update their networking assumptions, so this is still pretty common. And it doesn't help that most CGNAT users tend to be either from poorer, since poorer countries and mobile data providers are far more likely to use CGNAT than legacy North American ISPs.

[0]: https://tailscale.com/blog/how-nat-traversal-works

[rescbr]

> people tend to be pretty slow to update their networking assumptions, so this is still pretty common.

My ISP doesn't do CGNAT in FTTH deployments, but I'm paying extra for a static IPv4 allocation anyway since I was increasingly getting hit with captchas every time my IPv4 rotated to flagged IPs that were trashed by my fellow subscribers with poor infosec practices - i.e. 99.9% of residential subscribers.

Once I got a static allocation, captchas are getting easy to pass.

[Hendrikto]

> Is IPv6 really that widely used?

Mobile carriers use it almost exclusively, which is already a huge chunk of the internet, and newer ISPs are switching to it too.

> I'm supporting both because I heard it's good to support both, but I'm not sure what the actual benefit is.

The benefit is that you allow IPv4-only and IPv6-only clients to connect.

[tormeh]

I accidentally became the user of an IPv6-only device a while back for some obscure reason I never could figure out. Let me tell you: There are no IPv6-only users. Absolutely nothing except Google, Facebook, and YouTube works. Any website not in the top 20 are IPv4-only. It was so bad I briefly thought I didn't have an internet connection at all. Anyone stuck on an IPv6-only connection would immediately cancel their contract on the grounds that they don't have de-facto internet access.

[inigyou]

So, like, the three most popular things still worked. I wonder if working more is related to their popularity.

[tormeh]

I think it's more that Google and Meta have the surplus engineering resources to implement IPv6 for what is essentially no reason.

[inigyou]

Probably for lower latency and higher reliability on mobile networks.

[hdgvhicv]

You can do IPv6 only if you have a 64 nat on your edge and use dns64 and just use a limited set of applications and devices.

Some applications will still fail to work though unless you also have 46 nat on your device which still doesn’t work transparently on majority of types of device.

You also need all devices on your lan to support v6 natively, and v6 only. From your printer to your speaker.

You might be able to do something with mdns and nat64 to get them working on an IPv4 only subnet. But you’re talking layers and layers of complexity for things which just have to work.

I’m posting this from my phone on my IPv6 only subnet, not sure if it’s using a 64 gateway or 6 native to HN, but it’s possible.

[Hendrikto]

All the more reason to support it. There are lots of ISPs that only assign you an IPv6, and do hacky trickery to make IPv4 work over that. We wouldn’t need all of this.

[jon-wood]

When hosting a server IPv6 doesn't make a huge difference beyond your logs will probably be a bit more accurate, people behind CGNAT where an ISP has multiple customers sharing a block of IPv4 will show up with their actual IPv6 address. They'll maybe also find it slightly quicker because they're not being funnelled through NAT gateways but realistically not enough to notice.

From the user side IPv6 is great for me. My ISP is using CGNAT and would bill me ten pounds a month for a static IPv4 address but I automatically get a vast block of IPv6. I'm using that block to allow me to VPN back home when out and about, and if I wanted to I could also host services from devices on my home network without needing any NAT nonsense, I can just open access to the relevant device on the router. (Because this is a world where not everywhere supports IPv6 yet if I'm on an IPv4 only network the VPN endpoint is a dedicated server I rent which forwards the relevant port back to my home router over IPv6)

[hdgvhicv]

So your isp is rinsing you for the cost of a an IPv4 address. £10 a month will pay for a whole /24 in 3 years.

Chances are they also skimping on other areas including over subscription. Choose a better isp if you want a better service.

Your “just open traffic to internal host 1 on your firewall is the same no matter if it has nat or not, unless you are using a non stateful firewall? Or perhaps your configuration layer splits the two for reasons.

[jdw64]

Thank you for the advice. By any chance, have you worked with Ruby before? I remember seeing your username back when Ruby was popular and I first started learning it in university

[nottorp]

I recently enabled ipv6 on an unadvertised server i use just with people i know... it's on my home connection actually.

The great news is those vulnerability scans from random IPs are coming just on ipv4, there hasn't been any yet on ipv6 :)

[inigyou]

A lot of internet spambots and vulnerability scanners are v4 only. I discovered this when I found an open mail relay on v6, contacted the owner and he said it's been like that for ages due to a config mistake and he'd never heard a complaint. It wasn't an open relay on v4.

[newsoftheday]

My selfhosted email has been dual stack for close to a year and my eyeball estimate of the logs is around 10% of the traffic is IPv6.