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Why IPv6 is so complicated

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Re: Why IPv6 is so complicated

#461

Post by zadikian »

johncolanduoni wrote: post #457
hackthemack wrote: post #416

Earlier quoted context omitted.

Opening a dual stack ipv4 and ipv6 does allow the service to accept both ipv4 and ipv6 connections. But I do not think that is what zadikian is getting at? It does not address the network level identity and reachability. There is no default, globally routable mapping where owning a ipv4 automatically gives you an equivalent identity in ipv6 that others can reach without translation infrastructure. The transition mech…

I’m not clear on who is supposed to do the translating that isn’t doing it today, or why the mapped IPv4 addresses don’t qualify. Virtually all ISPs either give you an IPv4 address or do the translation for you, and the software you write doesn’t have to care exactly how it’s set up for the most part (there’s some subtlety about stuff like MTUs, but if you’re just doing unencapsulated TCP it usually doesn’t matter).…

If you look at the reasons GitHub for instance doesn't support ipv6, it's a different set of problems from what cell carriers had to deal with.

Re: Why IPv6 is so complicated

#462

Post by zadikian »

tardedmeme wrote: post #411
izacus wrote: post #358

Earlier quoted context omitted.

That's because they actually get paid for providing a reliable service, not for ipv6.

Access to only half the internet isn't exactly a reliable service. None of china, none of africa, only half of europe, none of south america....

Those are regions that have a lot of v6 support alongside v4, not v6-only.

Re: Why IPv6 is so complicated

#464

Post by zadikian »

tonymet wrote: post #442
tardedmeme wrote: post #418

Earlier quoted context omitted.

Because they didn't realize how that was the fundamental problem. There are some designers who knew their system would be incompatible but thought it was interesting enough to design anyway, like RINA. There are other designers who just didn't realize why this was a problem, like ipv8. The ipv8 designer is currently berating the NANOG (north america network operators group) mailing list for not already supporting ipv…

some of the alternatives were simpler and deliberate attempts to reduce the scope of the migration problem. You can’t say “all approaches would have suffered the same migration effort” as if it’s a given. That’s like saying UTF8 and UTF16 had the same migration effort because they both tried to migrate from 1-byte code points. UTF8 was way easier.

Yeah and UTF-8 shouldn't be taken for granted. I always wondered why there's still UTF-16 in so many places, even Swift strings (apparently changed in v5)... It's cause that was the natural replacement for UCS-2, which for certain reasons was beating UTF-8 early-on.

Re: Why IPv6 is so complicated

#465

Post by tardedmeme »

zadikian wrote: post #458
tardedmeme wrote: post #454

Earlier quoted context omitted.

They're allowed to do that if they want to. Most find there's no practical reason to ensure the addresses are related. It wouldn't help them support v6 faster.

Do they own such an address, as in, a packet sent by someone on another ISP to that address will actually reach my ISP's router over v6? Not talking about translations that use v4. If they do, I've never seen them actually give it to me.

Yes, they can just put your 32-bit IPv4 address after their 32-bit prefix, and that gives you a /64 as is standard. If they want to. But what's the advantage?

Re: Why IPv6 is so complicated

#466

Post by tardedmeme »

zadikian wrote: post #456
tardedmeme wrote: post #453

Earlier quoted context omitted.

How would this work if your upstream router doesn't support v6? All other networks send packets towards you, but your ISP ignores them because they are invalid packets. Then what?

It requires the router to support v6. If you want, could do an approach kinda like "happy eyeballs" where you try both.

If the whole path supports ipv6 what is the purpose of the compatibility trick?

Re: Why IPv6 is so complicated

#467

Post by tardedmeme »

ghusto wrote: post #422
everdrive wrote: post #372

This is the only topic that tempts me to create a throwaway account. (I have not given in) None of the IPv6 proponents are willing to acknowledge that IPv6 is a pain. All of them seem to have gone to some secret seminar somewhere where they receive their talking points: - Everyone who dislikes IPv6 doesn't know how NAT works and thinks it's the same as a firewall. - There's absolutely no downside whatsoever to being…

In troubleshooting, "It's always DNS" has become "If it's not DNS, it's IPv6". I don't even try to fix it. If I disable IPv6 and everything starts working, I move on.

On my network, if it's not DNS, it's IPv4. IPv6 just works. I wish websites would hurry up and get with the times so I could turn off this old pile of hacks already.

Re: Why IPv6 is so complicated

#468

Post by tardedmeme »

zadikian wrote: post #462
tardedmeme wrote: post #411

Earlier quoted context omitted.

Access to only half the internet isn't exactly a reliable service. None of china, none of africa, only half of europe, none of south america....

Those are regions that have a lot of v6 support alongside v4, not v6-only.

Most v4 support is through a gateway. You can't tell the user's IP address from the wrong side of the gateway, for example - only the gateway's address. The user isn't on v4, the gateway is.

Re: Why IPv6 is so complicated

#469

Post by tardedmeme »

zadikian wrote: post #455
tardedmeme wrote: post #450

Earlier quoted context omitted.

Would it help at all? You can't just send IPv6 packets down the equivalent IPv4 path because that bext-hop router probably xoesn't understand IPv6 packets. In fact there could be no IPv6 path at all between you and the destination, so knowing where they are still wouldn't help you forward packets. If it understood them, it would have given you an IPv6 route anyway. Updating BGP to support IPv6 routes wasn't an actual…

There are lots of services I can't send v6 to, not because some router in the middle only understands v4 but because the service operator decided not to deal with v6.

So the idea is to surreptitiously install software on the service operator's machines that they can't disable?

It's already a bit like that, but they can and do disable it. You can see the other comments in this thread: many people disable IPv6 upon any sign of a networking problem.

Re: Why IPv6 is so complicated

#470

Post by globular-toast »

mixmastamyk wrote: post #447
globular-toast wrote: post #396

Earlier quoted context omitted.

This comment would make more sense if you said why IPv6 is a pain. It just works for me.

Works but addresses are unreadable. Ensuring security on a small network is more difficult than it needs to be when addresses are gibberish. Still not sure mine is on IPv6.

Can you give examples of when you need to know IPv4 addresses for security reasons?
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