[tracker1]

I know that on my hosted server, I never bothered to set it up, because I didn't know how to properly configure or sub-net it. I know it's skill issue, but really feels significantly more complicated and even harder to understand than NAT even.

Not to mention, at home, most of the ads I do see (PiHole) are IPv6 addresses.

[unethical_ban]

No network is "smaller" than /64. All end-networks are /64.

Split subnets at four bit chunks.

Allocated networks, like to a home or small office, should be /56 or /60.

Then you have to think about link-local addresses and privacy addresses, and how to hand out IPv6 and configure DNS: SLAAC vs. DHCPv6 or some combination.

I have a rough draft of a beginner document but it's not ready. :)

[zrail]

(Pedantically) Maximum prefix length of /64 is only required if you want/need SLAAC. If you're assigning static addresses or using DHCPv6 for assignment you can go as small as you want. It's not weird to see /127 for tunnel subnets, for example.

[unethical_ban]

I didn't want to encourage non-standard behavior, but you are correct. Tunnels are a common use the same way /31s can be used in IPv4.

Going smaller than /64 is against best practice and unnecessary. People coming from IPv4 need to understand that trying to be careful with subnet sizing for purposes of preserving space is not a thing in IPv6 below /64. Maybe if a residential user has a /64 from their crappy ISP settings they'd need to do it, but not in a properly configured scenario and certainly not in enterprise.

[inigyou]

If you have a network full of static addressed servers, you can go as small as you want. For WiFi networks random devices may connect to, you should just let them pick their own address in a /64 with SLAAC. You may choose to also let servers use SLAAC if you want to, in addition to their static address.

[DrewADesign]

It seems to have absolutely terrible ergonomics as a technology, in nearly every conceivable way.

[inigyou]

It's literally impossible to avoid long addresses being long or short addresses running out. One of those is a worse problem.

[DrewADesign]

The length isn’t the only thing that makes the ergonomics suck. The lack of backwards compatibility sucks. The “you don’t have to use NAT anymore” is great theoretically, but it renders a lot of casual network maintainers mental model of network security obsolete without a clear and simple alternative. The shorthand is not intuitive (though it’s not CIDR-level counterintuitive). Really, there’s way too much about working in IPv6 that’s not intuitive with even very solid IPv4 network knowledge.

So yeah, having to relearn a bunch of basic network knowledge that worked just fine for decades is a PITA, and I’m 100% positive a design process that focused more on the people that need to configure networks could have yielded a much friendlier, and therefore a much easier to adopt standard.

[ndriscoll]

Instead of forwarding a port to a specific machine on the NAT page, you allow incoming traffic on that port to that machine on the firewall page. You'll want to add a stable IP to the host (in addition to the SLAAC rotating privacy IP if it already has one. One interface can have multiple addresses). That's pretty much it, except now you can allow the same port to multiple machines, where previously you could only forward to one (helpful for gaming, voip, etc. Wherever p2p works well). Firewall should already default deny incoming traffic just like ipv4.

[ssl-3]

That sounds easy, but I think you just inadvertently demonstrated the quagmire that many seem to perceive.

Suppose I've got a machine on the LAN and I want to open it up to the world on port 1025 with IPv6.

This can't happen with SLAAC? It has to be a new address? Does the ISP pick the prefix for that address? And one can't centrally-manage that address (because people keep saying that DHCPv6 isn't worth stuffing around with)? What happens when the router fails over to a backup ISP? How does dynamic DNS fit in with all of this?

Those questions don't really exist with IPv4, wherein: One can just set up a static DHCP assignment, forward port 1025, and [optionally] set up dynamic DNS -- and this all happens within the confines of a single home router.

[ndriscoll]

If it's MAC based SLAAC, it'll be stable, so you could use it. Otherwise you add a stable address. You could use DHCP if you want. If you're using a backup ISP with dynamic DNS, your failover should be the same as ipv4. You can already have ips from both prefixes on the interface. You're also way past clueless home user stage if you have that setup at all, so I can't imagine ipv6 is the stumbling block.

Things would be nicer if NAT66 were used by default for home users though so the question of prefixes would disappear, and it'd perhaps match the "more advanced" home user ipv4 mental model. You'd just use e.g. fd00::2 as your server address.

[redeeman]

you fling around words like "network maintainers" quite casually, dont you? :)

its really extremely simple, just dont NAT, is that really so hard? just because you dont NAT, doesnt mean you have to let the traffic pass through, that is also an extremely simple concept, no?

[DrewADesign]

Fling it around?

There are a shitload of people who maintain networks, like home or small business networks, that aren’t network administrators. Most of those people are not prepared to have their Chinese WiFi cameras, myriad smart appliances, and heck, even home computers easily individually accessible from the internet. It’s an extremely simple concept, no?

[inigyou]

Actually I think most people really do want that stuff accessible from the internet. Currently that requires a central server and a subscription, but imagine if it didn't. Imagine if you could log into your washing machine from anywhere instead of only when you're at home, and it would keep working even if LG went bankrupt.

[ssl-3]

Lack of NAT doesn't imply lack of firewall, though.

And home routers have firewalls that block inbound connections by default -- including with no-NAT IPv6.

[LocalH]

NAT is good. It's CGNAT that's bad, because that's NAT imposed on subscribers, and not NAT that they control.

[redeeman]

nobody suggests they should be, the ONLY difference is that the routers will block inbound connections by default, and you open your port in the firewall section instead of the shitty router instead of the nat/port forwarding