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The world in which IPv6 was a good design (2017)

apenwarr.ca

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Re: The world in which IPv6 was a good design (2017)

#311
post #169

Earlier quoted context omitted.

> The "mobile IP" problem isn't IP's job and should not be. IP should be as stateless as possible because this makes it cheap and easy to add capacity and redundancy to a network. But, to be clear, many implementations of IP (both IPv4 and IPv6) do already have "mobile IPs." There's nothing stopping you from having "mobile IPs." They're just complex, and only work when everywhere the IP can move between all exists wi…

> You can move between multiple wireless APs in a conference hall, and have a layer-3 address that follows you as you switch network segments and thus acquire new layer-2 addresses (which means that the packets destined to that address are being dynamically re-routed at some upstream switch, as the address assignment changes.) Is it possible to implement this at home, without paying a lot of money? I've tried it with…

For a house, you probably just want wireless range repeaters/extenders, or mesh APs like these (https://www.wired.com/story/best-mesh-wifi-routers/). Their key advantage being that the backhaul is wireless — you don't have to wire them back to the switch.

If you really want to do an "enterprise" wireless setup, and you want it to be cheap, well... you can buy the relevant equipment (802.11 enterprise wireless APs) used, often in bulk. Sometimes computer recyclers even have them!

Make sure you buy the stuff intended for office buildings, though, not the conference-hall open-plenum equipment. The conference-hall stuff is like studio lighting: powerful at a distance (five-storey hall ceiling down to you on the floor) at the expense of guzzling power and dumping tons of heat.

Also, obviously, unlike the home stuff, with the enterprise hardware, you do need to be able to run an Ethernet backhaul back to a switch somewhere, to join all these APs' L1 collision-domains into a common link-layer network segment. And that switch has to understand what it's doing, so you'd probably need something enterprise-y there, too, unless the state of open-source consumer router firmware has really caught up with enterprise.

Re: The world in which IPv6 was a good design (2017)

#312

Earlier quoted context omitted.

Yeah, that's smart. There's no need for everything to be uniquely identified on the internet anyway, right? Why would someone halfway around the world need to be able to ping my smart fridge after all? Even for tech support purposes, people shouldn't have the ability to directly test my appliances firewall capabilities. Actually, now that I've done the math, why not just extend IPv4 into hexadecimal? Once again, none…

> what's not to love about it hexadecimal, unironically. the url of http://[2002:914b1:::1] is one of my major sticking points for IPv6. i'd rather just have it be 16 octets or even 8 decimal quartets where each thing is required. http://0.0.0.0.0.0.0.0.0.0.0.0.192.168.1.1:14246 would've at least looked a bit better than it is. would've been super easy too. imagine the convo: "what's google's DNS IP in IPvX?" "oh it'…

Decimal addresses are an artifact from the time before CIDR, when subnets were always /8, /16, or /24. IPv4 subnet math now requires obscure binary/decimal conversion. Hexadecimal fixes that problem.

Re: The world in which IPv6 was a good design (2017)

#313

Earlier quoted context omitted.

Based on "speak seamlessly to IPV4 and IPV6", I don't think I did. At the very least it would need to speak seamlessly to v4, which as you say is obviously not possible for any address length bigger than 32 bits. > The real, the big question here is: was there some single obvious thing that IPv6 failed to do or failed to include that has made its uptake so slow? It's taken some 30 years to reach approximately half th…

Hmmmm. I am not a network engineer (any more, thank the hypothetical deities) so I have no skin in this game. But in the 1990s, I moved networks from IPX/SPX, or NetBEUI, or AppleTalk, or DECnet, and almost any combinations thereof, to IP. I added IP on top of existing networks. I migrated systems from 10base-2 to 10base-T to 100base-T. I stitched together WANs. Then I moved IP networks from static to DHCP, from no n…

I don't think the original rollout of the v4 internet really counts as a migration project, because there was no "NetBEUI internet" or "AppleTalk internet" to migrate from in the first place. IPX/SPX/NetBEUI/AppleTalk/DECnet all either run on only a single L2 network, or were only used in small, local groups of networks. Nothing existed that linked every network on the planet together in a single shared address space. You can't migrate a global network from one protocol to another when the global network you're migrating from doesn't exist yet; that's a new deployment, not a migration.

As a result, network effects [in the economic sense of the term] worked in favor of deploying v4, but they work against deploying any replacement to v4.

You could argue that it required migrating local networks, and it did, but migrating from IPX/etc to IP is fundamentally simpler than migrating v4 to v6, because you only need to worry about your local network -- which you have full authoritative control over and can mandate a migration deadline for. You didn't need to worry about maintaining compatibility with the IPX Internet either, because there wasn't one.

Note that I'm drawing a distinction between a network and an internet. IPX/etc only did the former, IP does both. The level of challenge in migrating a network (even multiple of them) is very different to migrating an entire internet, due to the interconnectivity or lack thereof between the networks.

You're also talking about a time when there were three orders of magnitude fewer networked computers, and relatively little networked software except for the vendor software that came with the network stacks in the first place, which wasn't expected to be compatible with any other network protocol.

Moving from static networks and hosts files to DNS and DHCP, is all L4 stuff, and could be done without changing L3. Similarly with firewalls and NAT: there's no need to change L3 to implement those and their deployment is a local-network-only project.

You make a good point that the 90s had far more technological change -- it must have been interesting to live through. But it was technological change that was fundamentally easier to deploy because it only involved making local changes on each network, not changes on all networks. v6 doesn't have that luxury because v6 is replacing the IP address, which is the one thing that goes end-to-end through all of the networks.

So yeah, that's my argument for not agreeing that the original rollout of v4 was bigger or harder than v6, even though it involved more technological changes. It's not the technical difficulty but the sheer scale of the deployment -- v6 needs to deal with far, far more software, devices, networks and involved people than anything v4 had to deal with in the 90s -- and the strength of the network effects that worked in v4's favor but which are working against v6.

> Similarly, although it's not my area, it's an interesting line of questioning to ask "what is wrong with IPv6 that the world didn't move to it, and can we fix that?"

I don't think it's fair to say that the world didn't move to v6, because the world is moving to v6. It's gone from 50 million users to 2.3 billion users in the last 10 years. That's about the number of people that were using v4 at the start of those 10 years.

I'm not treating these questions as heresy, it's just that we keep seeing the same broken takes over and over and it gets very tiring. Things like "v6 would have been deployed in 5 years if they had just added some zeros to the beginning of v4 addresses", from somebody who doesn't have a clue how to make that work and who doesn't know enough to realize that it can't work. There are dozens of people like that just in the comments to this article alone. You can't expect posts like that to be taken seriously by anyone that knows what they're talking about.

> It's good but it only fixes 1 problem

It's interesting that you say this, because the person I replied to above said "I think it was protocol design hubris: we are fixing SO MUCH STUFF that people will flock to this irresistible shining trophy of protocol design."

Is it fixing too much stuff or too little stuff? You guys can't even agree on that!

Re: The world in which IPv6 was a good design (2017)

#314

Earlier quoted context omitted.

Hmmmm. I am not a network engineer (any more, thank the hypothetical deities) so I have no skin in this game. But in the 1990s, I moved networks from IPX/SPX, or NetBEUI, or AppleTalk, or DECnet, and almost any combinations thereof, to IP. I added IP on top of existing networks. I migrated systems from 10base-2 to 10base-T to 100base-T. I stitched together WANs. Then I moved IP networks from static to DHCP, from no n…

I don't think the original rollout of the v4 internet really counts as a migration project, because there was no "NetBEUI internet" or "AppleTalk internet" to migrate from in the first place. IPX/SPX/NetBEUI/AppleTalk/DECnet all either run on only a single L2 network, or were only used in small, local groups of networks. Nothing existed that linked every network on the planet together in a single shared address space…

...okay, I guess that was a bit of a wall of text, sorry about that. This was actually an interesting line of conversation for once, rather than picking apart yet another "just put 2^128 numbers into 2^32 holes, it'll be fine" post.

Re: The world in which IPv6 was a good design (2017)

#315
post #111

Earlier quoted context omitted.

> And until we can start disabling v4, v6 gives no advantage and only causes significant added complexity. v6 advantages: * If you're an ISP, you need more complex hardware for CGNAT-v4 if your traffic is huge. If you do support v6, netflix, youtube and majority of your traffic is already on v6, you can get by without upgrading your CGNAT Infra. * I suspect v6 should have faster initial connection - time to first byt…

* Until the transition is complete, I and everyone else is gonna have to use an ISP which provides a v4 address, whether they're end users or a server operators. Fair enough though that ISPs may have some incentive to making more people have v4+v6 (not that they seem to have realized...) * I really don't think NAT could possibly make a noticeable difference in the time to first byte. My guess about what's "barely not…

s/w stack penalizes IPv4 by 25 ms to 300 ms. This is not a point to say that v4 is bad, but has been made bad artificially: https://ma.ttias.be/apple-favours-ipv6-gives-ipv4-a-25ms-pen...

Re: The world in which IPv6 was a good design (2017)

#316
post #311

Earlier quoted context omitted.

> You can move between multiple wireless APs in a conference hall, and have a layer-3 address that follows you as you switch network segments and thus acquire new layer-2 addresses (which means that the packets destined to that address are being dynamically re-routed at some upstream switch, as the address assignment changes.) Is it possible to implement this at home, without paying a lot of money? I've tried it with…

For a house, you probably just want wireless range repeaters/extenders, or mesh APs like these ( https://www.wired.com/story/best-mesh-wifi-routers/ ). Their key advantage being that the backhaul is wireless — you don't have to wire them back to the switch. If you really want to do an "enterprise" wireless setup, and you want it to be cheap, well... you can buy the relevant equipment (802.11 enterprise wireless APs)…

Extenders works very badly, as they use 1/2 of bandwidth for themselves and need to be placed twice as often as APs. I have no problem to wire normal APs to switch, as I have several RJ45 sockets in each corner of each room :-)

Now I have one AP per room already, but can not implement seamless transition - when phone/laptop switches to other AP it requests DHCP again and drops all connections. It is very inconvenient.

I know "Buy Cisco's APs for $700/piece and controller for several thousand $$$", I wander why there is no open-source solution (hostapd & Ko), which "secret source" these enterprise solutions include, is it private technology or some open industrial standards, like 802.11[some obscure letter]?

Many expensive APs are built with Linux and hostpad inside, and still doesn't support this feature.

Re: The world in which IPv6 was a good design (2017)

#317

Earlier quoted context omitted.

> what's not to love about it hexadecimal, unironically. the url of http://[2002:914b1:::1] is one of my major sticking points for IPv6. i'd rather just have it be 16 octets or even 8 decimal quartets where each thing is required. http://0.0.0.0.0.0.0.0.0.0.0.0.192.168.1.1:14246 would've at least looked a bit better than it is. would've been super easy too. imagine the convo: "what's google's DNS IP in IPvX?" "oh it'…

So, in my IPv4.1 suggestion, every address you currently know would work perfectly fine. But then so would AE1.224.78.BC2 Sure, a little harder to remember maybe, but adding nearly a billion times as many IP addresses would alleviate the strain on the internet, be backwards compatible with IPv4 (but not forwards compatible, so most interior/home networks would use either a NAT or have a software ipv4-4.1 bridge softw…

Wait, you wanted to extend the text representation of v4 addresses? That's not a thing that exists in the protocol. The addresses are in binary in the packet format and in all data structures, so any extension of the character set in the text representation has to be implemented by increasing the bit length of the addresses.

I don't know why you think this is "inherently backwards compatible" yet think v6 isn't. It's just as backwards-compatible as v6 is.

Re: The world in which IPv6 was a good design (2017)

#318

Earlier quoted context omitted.

Hmmmm. I am not a network engineer (any more, thank the hypothetical deities) so I have no skin in this game. But in the 1990s, I moved networks from IPX/SPX, or NetBEUI, or AppleTalk, or DECnet, and almost any combinations thereof, to IP. I added IP on top of existing networks. I migrated systems from 10base-2 to 10base-T to 100base-T. I stitched together WANs. Then I moved IP networks from static to DHCP, from no n…

I don't think the original rollout of the v4 internet really counts as a migration project, because there was no "NetBEUI internet" or "AppleTalk internet" to migrate from in the first place. IPX/SPX/NetBEUI/AppleTalk/DECnet all either run on only a single L2 network, or were only used in small, local groups of networks. Nothing existed that linked every network on the planet together in a single shared address space…

I disagree with the overall point you're making here, but I can see that you are seriously committed to it, so I think that no amount of examples of internetworks from the 1980s and 1990s is going to persuade you: to you, I think they'd all be toy-scale and thus irrelevant.

Networking in the 1980s and early 1990s was all small LANs, for the vast majority of users, and for PC-type kit.

But there were internetworks, yes. DEC ran a global network; DEC tech support was my first experience of true worldwide follow-the-sun support, where the techs on 3 different continents could pick up my case from a single shared database and help me move it forward.

I was sysadmin of the London node of a DECnet internet that spanned Oslo, Copenhagen, Stockholm and Helsinki. No IP links between the sites, just DECnet.

Companies were running global IPX internetworks: that is how the problems with scaling Netware 3's bindery database arose, which is why Novell developed NDS and Netware 4.

Yes, it was a thing. Updating and modernising it was hard.

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