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Tell HN: IPv6-only still pretty much unusable

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Re: Tell HN: IPv6-only still pretty much unusable

#441

Post by error503 »

cj wrote: post #178
yesco wrote: post #122

Earlier quoted context omitted.

A confusing aspect of IPv6 is that it's actually a much simpler protocol than IPv4, you often end up assuming you need to configure a bunch of stuff that you really don't have to. The most common example would be NAT, despite the complexity it adds to IPv4, people often get comfortable with idea of setting up complex subnet hierarchies and feel lost when that all just disappears with IPv6. The key things to remember…

I have the technical ability to set up a well structured VPC in AWS with private/public subnets, but I wouldn't know where to start if asked to set up an ipv6-only network. Is the general model of public/private subnet still valid? Or are you saying in a ipv6-only world, there's no need for separate subnets? There's something about a server not being assigned an IP address at all that makes me sleep easy at night (in…

> Is the general model of public/private subnet still valid? Or are you saying in a ipv6-only world, there's no need for separate subnets?

This is one thing that's actually been vastly improved in IPv6 (IMO), though I guess it is somewhat more complicated, it is standardized.

In the IPv4 model, your hosts get 'internal' addresses and some gateway device translates these addresses to/from the associated 'public' addresses as necessary. Behaviour when multiple addresses are assigned is undefined, and there are plenty of weird corner cases with internal hosts trying to hit the public addresses of forwarded services and such.

In the typical IPv6 model, your hosts (if they need to talk to the Internet) get a (or several) Globally Unique Address (GUA), which is routeable on the Internet. Optionally, hosts can also have a Unique Local Address (ULA) which is analogous to an RFC1918 address in IPv4. Because it's codified in the standard, hosts will choose the correct source address depending on the destination they want to talk to; a ULA address if the server is also ULA, and a GUA source will be chosen for talking to GUA addresses.

In a typical corporate network, you'd give hosts both classes of address, and your internal services run on ULA addressing. But in most residential or hosting environments, you'd just use GUA as there is no benefit to segregating things this way.

Re: Tell HN: IPv6-only still pretty much unusable

#442

Post by superluserdo »

uuddlrlrbaba wrote: post #322
kd913 wrote: post #265

Earlier quoted context omitted.

>It’s impossible to finish a transition when the old version has no end of life in sight. The end of life is gonna happen when ipv4 addresses end up being cost prohibitive. They are already some $50 an ip address. That is gonna be cost prohibitive in developing Countries, who already are making a transition to ipv6.

Increased demand will drive the price up, but that's not end of life. Developed countries will pay obscene amounts for ipv4 space. Just as they do for shorthand .com domains.

Short .com domains actually have an intrinsic value to their prospective owners though, since the domain is the human-readable address, and a shorter address is more memorable to customers. The version of the underlying network protocol is just an implementation detail that the vast majority of companies (basically everyone besides possibly 1.1.1.1 and 8.8.8.8) would happily drop if it became totally unnecessary.

Re: Tell HN: IPv6-only still pretty much unusable

#444

Post by Dagger2 »

__d wrote: post #399
Dagger2 wrote: post #355

Earlier quoted context omitted.

Just like IPX. It's still necessary and in use for some things -- so it hasn't reached its end of life -- but when was the last time you ever thought about it? By this metric, we still haven't finished migrating to v4.

I'm curious: what still uses IPX in 2022?

Red Alert 2! They never added IP-based LAN play to it.

Re: Tell HN: IPv6-only still pretty much unusable

#445

Post by p_l »

wbl wrote: post #419
theamk wrote: post #345

Earlier quoted context omitted.

Or you extend on network level, and even kernel level, but keep programming API compatible. I don't think people like IPv4 packets that much, it is all the APIs which are giving problem. I bet if we kept everything about IPv6 the same, but (1) made IPV6_V6ONLY mandatory and default to zero (2) did not use colon in IP address representation (3) recommended firewalls use same config rules for IPv4/IPv6 address.. then I…

That mistake was already baked in to the sockaddr_t ABI.

BSD Sockets were one giant mistake of not enough abstraction and leaky implementation internals like that.

Re: Tell HN: IPv6-only still pretty much unusable

#446

Post by p_l »

Dagger2 wrote: post #413
anyfoo wrote: post #379

Earlier quoted context omitted.

Yeah, but I have to say, even as someone who wants IPv6 to succeed and supersede IPv4, from the perspective of building that network infrastructure software, I think this "IPv4+" would have been massively simpler to add, extremely so, and that may have aided adoption a lot. It's really hard to overstate how much simpler tacking on 128bit IP addresses to an otherwise unmodified protocol would have been in the software…

The majority of the problems seem to come from the fact that v6 addresses are longer than v4 ones. That's why we need socket(AF_INET6)s and AAAA records and a DNS API that supports multiple address families and dual stack and new firewalling and updates to all protocols that embed v4 addresses. You're going to have the exact same problems with any protocol that has addresses longer than v4's.

BSD Sockets ensured that we have problems using anything other than what the software was originally written for, unless it's a program recent enough to use the one bit of API that got back ported from OSI-oriented Ed networks, the getaddressinfo() call.

Otherwise there's a ton of low level IPv4 details leaking all around the basic idea of connecting from one service to another.

Re: Tell HN: IPv6-only still pretty much unusable

#447

Post by icedchai »

SoftTalker wrote: post #361
293984j29384 wrote: post #295

Earlier quoted context omitted.

While I don't have any factual proof to refute your statements, in my personal experience almost every organization uses NAT & RFC1918 address space. The only client I can think of in my 20 years of experience that used a public IPv4 per VM/machine was the DoD, specifically, the U.S. Army. From your very last statement, I think you've confused self hosting (like buying a VPS from Digital Ocean and hosting your own bl…

Big universities (at least in my experience in the USA) are the other ones that would have a public IP address for every device, at least until rather recently. They were online very early and got allocated huge blocks of addresses, before anyone really imagined future scarcity.

In the mid-90's, every system at my university had a public IP address, including those on the campus residential networks. There were no firewalls. It was also a flat address space (/16, 255.255.0.0) for the whole campus! The 90's were certainly a different time.

Re: Tell HN: IPv6-only still pretty much unusable

#448

Post by _8j50 »

Dagger2 wrote: post #364
_8j50 wrote: post #141

My take is that they should have used alphanumeric addressing. You could have addresses like company:office:laptop and it shouldn't have reinvented arp and dhcp or added more complex routing like anycast or link local. It tried to solve too many problems at once.

You're thinking of DNS, which... we already have. v6 actually changed very little from v4. It more or less works in exactly the same way v4 does.

No, ipv6. Could have eliminated the need for DNS in a LAN. There is no reason to use hex other than maybe it would be easier for control planes to translate config to bytes/asic? But that's only when a config changes. Routing and forwarding uses bits and bytes, the hex is just one of many ways they could have chosen to represent the bytes. Defining prefixes in alphanumeric and how that translates to bytes could have been worked out. It could be something like 2601:hchsh:eevbo::home/64 for example

Re: Tell HN: IPv6-only still pretty much unusable

#449

Post by jandrese »

EvanAnderson wrote: post #349
redox99 wrote: post #32

IPv6 has been one of the biggest failures in the last couple of decades. And I don't mean adoption, I mean the standard itself. If IPv6 were IPv4 with more octets, then we would all have been using it for like a decade. Yes, I understand it would still require some breaking changes, but it would have been a million times easier to upgrade, as it would be a kind of superset of IPv4 (1.2.3.4 can be referred as 0.0.0.0.…

There was an idea floated in the early 2010s to do an overlay network over IPv4 that did this just: https://seam.cs.umd.edu/EnhancedIP/index.html It "died" as an Internet-Draft: https://datatracker.ietf.org/doc/html/draft-chimiak-enhanced...

I don't see how this has any advantage over just deploying more NAT like people are already doing. Plus it adds IP options which routers hate.

They claim "EnIP supports end-to-end connectivity, a shortcoming of NAT, making it easier to implement mobile networks." but I don't see where mobile network operators would care about end-to-end connectivity?

Re: Tell HN: IPv6-only still pretty much unusable

#450

Post by icedchai »

codegeek wrote: post #282
redox99 wrote: post #32

IPv6 has been one of the biggest failures in the last couple of decades. And I don't mean adoption, I mean the standard itself. If IPv6 were IPv4 with more octets, then we would all have been using it for like a decade. Yes, I understand it would still require some breaking changes, but it would have been a million times easier to upgrade, as it would be a kind of superset of IPv4 (1.2.3.4 can be referred as 0.0.0.0.…

I always joke with "We figured out how to move from Python 2 to 3 but we still cannot figure out how to do IPv6" :). What a catastrophic failure it has been. Should we just stop using it altogether and retire or are there people still advocating ?

You'd be surprised. A former employer is still writing new Python 2 code.
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