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Why IPv6 is so complicated

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Re: Why IPv6 is so complicated

#71

Post by j16sdiz »

gucci-on-fleek wrote: post #51

In my experience, the IPv6 protocol is much simpler than the IPv4 protocol. However, the IPv6 tooling and documentation is still worse than it is with IPv4, and dual-stack is inherently going to be more complicated than implementing any single protocol, so I do have some sympathy towards "IPv6 is hard". For example, the IPv6 packet structure [0] is much simpler than the IPv4 packet structure [1]; SLAAC [2] is much si…

ULA give more trouble than what it solves.

Almost all computer have multiple interface (virtual or not). Application now need to know which interface the destination is on, and there is no easy data structure to store the interface

Re: Why IPv6 is so complicated

#72

Post by baq »

XorNot wrote: post #55
9dev wrote: post #34

Earlier quoted context omitted.

There are no more acronyms. SLAAC means automatic client configuration. That's the only one you need. > give up control of your home network. What does that even mean? What do you gain by deciding your Apple TV should be at 192.168.0.3? With IPv6, you can just `ping appletv` and it works fine. What more "control" do you need?

I mean generally I want fixed IPs on my local network for robustness. With IPv6 I actually want it more and it becomes possible since we can just use the MAC address as an IP address. I have IPv6 service at my ISP right now but I'm hesitant to turn it on on my local network because it does make my firewalling concerns much more critical.

What firewalling? You don’t have an ipv4 firewall?

Re: Why IPv6 is so complicated

#73

Post by gucci-on-fleek »

muppetman wrote: post #11

This annoys me, especially the last “It takes at least 25 years” rhetoric. It didn’t take 25 years for SSL. SSH. Gzip encoding on HTTP pages. QUIC. Web to replace NNTP. GPRS/HSDPA/3G/4G/5G They all rolled out just fine and were pretty backwards and forwards compatible with each other. The whole SLAAC/DHCPv6/RA thing is a total clusterfuck. I’m sure there’s many reasons that’s the case but my god. What does your ISP s…

> It didn’t take 25 years for SSL. SSH. Gzip encoding on HTTP pages. QUIC. Web to replace NNTP.

All that's required to implement each of those is two computers: 1 client and 1 server. Whereas supporting IPv6 requires every router between the two computers to also support IPv6. Similarly, if your current software doesn't support SSL/SSH/Gzip/etc., it's pretty easy to switch to different software, whereas it's hard or impossible for most people to switch ISPs.

> GPRS/HSDPA/3G/4G/5G

Radio spectrum costs providers millions of dollars, and each new cellular protocol increased spectrum efficiency, so upgrading means that providers can support more users with less spectrum. The problem is that most of the "Western" countries still have lots of IPv4 addresses, so there isn't much cost benefit to switching to IPv6. However, China and India both have lots of users and fewer IPv4 addresses, so there is a cost benefit to switching to IPv6 there, and unsurprisingly both of these countries have really high IPv6 adoption rates.

Re: Why IPv6 is so complicated

#74

Post by eqvinox »

eviks wrote: post #36

This is not very substantive, but rather procedural, like this example of an answer doesn't tell you much, but tells you the official paper IDs: > Actually, we tried that: the "IPv4-Compatible IPv6 address" format was defined in {{RFC3513}} but deprecated by {{RFC4291}} because it turned out to be of no practical use for coexistence or transition. Why/how did it turn out?

> Why/how did it turn out?

It is extremely hard (for Brian, but even more so for anyone else, I certainly can't) to give a good answer to that, since you're talking about the absence of utility. People had applications in mind but dismissed them because they either found better ways or it wasn't practical. But that very frequently doesn't result in a "paper trail".

(It's a bit like LLMs having problems with negatives/absences.)

Re: Why IPv6 is so complicated

#75

Post by JumpCrisscross »

collabs wrote: post #49
JumpCrisscross wrote: post #24

Earlier quoted context omitted.

> What does your ISP support? My ISP is Spectrum. They get a 0/10 on IPv6 support on this test page [1]. [1] https://test-ipv6.com

Is it possible that you own your own router and have at some point configured the router to turn up 6 off? I know it is turned off on my router because I had some issues with Verizon ipv6 and tp link in the past.

Good idea–on my list of to-check items.

Re: Why IPv6 is so complicated

#76

Post by nottorp »

9dev wrote: post #67
XorNot wrote: post #55

Earlier quoted context omitted.

I mean generally I want fixed IPs on my local network for robustness. With IPv6 I actually want it more and it becomes possible since we can just use the MAC address as an IP address. I have IPv6 service at my ISP right now but I'm hesitant to turn it on on my local network because it does make my firewalling concerns much more critical.

> I mean generally I want fixed IPs on my local network for robustness. What do you mean by robustness? Isn't it really stable hostnames that you want? I don't understand how fixed IPs increase resilience (to what?). > I'm hesitant to turn it on on my local network because it does make my firewalling concerns much more critical. Block everything coming in from outside the network. Allow established connections. That'…

You're assuming there is only one internet connection in my home network, for example. The "easy" trick where your ISP gives you routable addresses does not work when there's more than one exit.

Still want to help? :)

And really... everyone is pushing for SSL everywhere - among other things so that the ISP doesn't MITM your traffic.

Why would you allow the ISP to know what machines are inside your home network then?

Re: Why IPv6 is so complicated

#77

Post by threiw »

eqvinox wrote: post #68
threiw wrote: post #46

Earlier quoted context omitted.

On one of my linux machines the "localhost:8080" did not work after new installation. It resolves to local ipv6 address, while server only listened on ipv4. After this I go out of my way to disable, remove and nuke ipv6, out of every setup and deployment I do. Ipv6 is already quite complicated, but supporting TWO competing network stacks, with complicated pseudo compatibility, just multiplies unnecessary complexity!

Or, you could've fixed your server's configuration. Probably would've been faster than to "disable, remove and nuke ipv6". In general, the mistake is that it says "0.0.0.0" or "0.0.0.0:8080" somewhere where it should really say "::" or "[::]:8080". (IPv6 sockets by default accept IPv4 connections, unless you disable that either system-wide or on the specific socket.) By the way, I do agree the colon was a really poor…

I fixed the problem once for all. Now my program even refuses to start, if IPv6 is enabled. I am not going to spend time debugging problem, that can be easily prevented. Pretty valid solution on private networks and local only kubernetes deployments.

If customer wants proper ipv6 support, we can sign a contract and talk about it. But do not expect me to support some technology for free, just because it is enabled by default.

Re: Why IPv6 is so complicated

#78

Post by kmacdough »

nslsm wrote: post #18
ggm wrote: post #7

India on around 80% in the apnic labs active measurement of end users. https://stats.labs.apnic.net/ipv6/in They report nearly a billion users, predominantly in mobile. So, "only" 750 to 800 million users. Think about that: 3x the population of the USA using it most of the time, in one economy. Here's the rankings: https://stats.labs.apnic.net/ipv6/XA?o=cINw30x1r1 This is a different measure to Google's. They measure…

Now compare average income to see how much this matters.

I'm confused. What's your point?

Obviously economies that rely largely on second hand technology are going to have old technology. Much of Africa is in this bucket. But looking past the extremes, India is at nearly 80% right alongside Germany. They fall in very different average income brackets. So the correlation isn't tight.

I can't see any value in pointing out vague correlation between income and proliferation of a new technology. It's the most obvious of observations.

Re: Why IPv6 is so complicated

#79

Post by mindcrime »

JumpCrisscross wrote: post #24
muppetman wrote: post #11

This annoys me, especially the last “It takes at least 25 years” rhetoric. It didn’t take 25 years for SSL. SSH. Gzip encoding on HTTP pages. QUIC. Web to replace NNTP. GPRS/HSDPA/3G/4G/5G They all rolled out just fine and were pretty backwards and forwards compatible with each other. The whole SLAAC/DHCPv6/RA thing is a total clusterfuck. I’m sure there’s many reasons that’s the case but my god. What does your ISP s…

> What does your ISP support? My ISP is Spectrum. They get a 0/10 on IPv6 support on this test page [1]. [1] https://test-ipv6.com

FWIW, I'm also on Spectrum (by virtue of the Time Warner acquisition back in the day) and I get 10/10 on that page. That is, after turning off Firefox "Enhanced Privacy Protection" which actually blocked the page from loading at all for some reason. Got 9/10 using Chrome. Both on Linux.

Re: Why IPv6 is so complicated

#80

Post by eqvinox »

j16sdiz wrote: post #71
gucci-on-fleek wrote: post #51

In my experience, the IPv6 protocol is much simpler than the IPv4 protocol. However, the IPv6 tooling and documentation is still worse than it is with IPv4, and dual-stack is inherently going to be more complicated than implementing any single protocol, so I do have some sympathy towards "IPv6 is hard". For example, the IPv6 packet structure [0] is much simpler than the IPv4 packet structure [1]; SLAAC [2] is much si…

ULA give more trouble than what it solves. Almost all computer have multiple interface (virtual or not). Application now need to know which interface the destination is on, and there is no easy data structure to store the interface

You're confusing ULAs (Unique Local Addresses) with LLAs (Link-Local Addresses).

(ULAs don't need the interface specified.)

ULA: fc..:… and fd..:…

LLA: fe80:…

[ed.: By the way, sin6_scope_id is where the interface identifier is stored in struct sockaddr_in6. So, basically every single IPv6 address object you're handling has the field for it.]

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