Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why IPv6 is so complicated

github.com

Post reply on HN
Print view View original

291–300 of 519 posts

Re: Why IPv6 is so complicated

#291

Post by doctorpangloss »

ninkendo wrote: post #275
api wrote: post #268

It’s not. It’s IPv4 with more bits and some changes to Ethernet level lookup. The SLAAC vs DHCPv6 mess is not really a problem with the core V6 spec.

The changes to Ethernet lookup mandate that you have a link-local address in addition to your “real” address, and this starts the ball rolling on the idea that machines have multiple IP addresses in general. Which makes privacy addresses commonplace, ULA+GUA addresses on the same machine, etc. I think this is the biggest change with IPv6: that a machine’s IP addresses is no longer its identity, and you can’t easily p…

> I think this is the biggest change with IPv6: that a machine’s IP addresses is no longer its identity,

a little over half the bytes of a typical IPv6 visitor's address is comparable in identification to what all four bytes of an IPv4 address tells you

Re: Why IPv6 is so complicated

#292

Post by djha-skin »

alfons_foobar wrote: post #289
djha-skin wrote: post #271

Article does not address the elephant: there is no ability to NAT with IPv6. Sure, absolutely, you shouldn't have to NAT, but in my datacenter, NAT is a feature, not a bug. The article specifically asks "did the ipv6 designers go mad" and then they list features I've never heard of or use to prove they didn't. Those features are not why I think they went mad. The inability to create a NAT is. For this reason, at ever…

NAT is a crutch to circumvent the problem of "there are not enough addresses for each device". I _assume_ you are referring to a default deny inbound firewall (so that devices are not reachable from the outside), but these are very different, completely orthogonal concerns (and independent of the IP version in use).

Everyone I've talked to with this opinion are typically mobile devs thinking about cell phones. Ipv6 works great there, but NATs are often used in corporate networks for isolation and in particular obfuscation. You can't tell what's behind a NAT by inspecting traffic coming from inside it like you can with no NAT networks. Some of the networks I administrate are contractually obligated to be so isolated.

Re: Why IPv6 is so complicated

#293

Post by righthand »

api wrote: post #282
dgoodell wrote: post #279

Earlier quoted context omitted.

IPv4 + all the other stuff you need to actually make it work in the real world actually seems more complicated than IPv6 to me. Maybe they’re comparing the minimal implementation on a home network. But even then I’m not sure the claim holds up. People learned IPv4 when they were younger in a more incremental manner and take it for granted now.

V4 plus one or more layers of NAT and all that junk objectively is more complicated, but it’s the devil people know.

Is it a job security issue? Greyed Neckbeards keeping things overly complex because they’ve managed to cement themselves in with IPv4 systems and anti-IPv6 talk?

Re: Why IPv6 is so complicated

#294

Post by Ekaros »

hackthemack wrote: post #288

I think this is the kind of the topic that can be endlessly debated because you can not easily go back in time and test out alternate hypothesis. I will say that I do not like ipv6 because it tried to fix multiple accumulated problems. I know! How contrarian! How can you be against trying to fix things. But all of those issues made ipv6 a dual stack solution that replaced ipv4. Address exhaustion, Routing table scala…

How you would have implemented backward compatibility? I am interested to hear the general technical details of how this could have been possible.

I am mostly interested in two basic scenarios. With expectation that only on one side is any changes made. Host from new addressing scheme connecting to old one and receiving data back. Host from old addressing scheme connecting to one in new one and receiving data back.

Re: Why IPv6 is so complicated

#295

Post by bell-cot »

Short answer: Too many cooks in the kitchen, and too many of 'em motivated to make it more complicated.

A computer standard that is still widely avoided almost 30 years after it became official is a computer standard that should have been tossed in the bin before the ink was dry.

Re: Why IPv6 is so complicated

#296

Post by djha-skin »

LambdaComplex wrote: post #281
djha-skin wrote: post #271

Article does not address the elephant: there is no ability to NAT with IPv6. Sure, absolutely, you shouldn't have to NAT, but in my datacenter, NAT is a feature, not a bug. The article specifically asks "did the ipv6 designers go mad" and then they list features I've never heard of or use to prove they didn't. Those features are not why I think they went mad. The inability to create a NAT is. For this reason, at ever…

What purpose do you have for NAT other than putting it where you should actually be putting a firewall?

Obfuscation. By inspecting packets coming from my network now you can tell what MAC addresses are in my network and also internal network topology. It's part of the reason your cell phone feels the need to randomize its MAC.

Re: Why IPv6 is so complicated

#297

Post by djha-skin »

Veserv wrote: post #283
djha-skin wrote: post #271

Article does not address the elephant: there is no ability to NAT with IPv6. Sure, absolutely, you shouldn't have to NAT, but in my datacenter, NAT is a feature, not a bug. The article specifically asks "did the ipv6 designers go mad" and then they list features I've never heard of or use to prove they didn't. Those features are not why I think they went mad. The inability to create a NAT is. For this reason, at ever…

1. IPv6 does have NAT [1], NAT66. 2. NAT is totally orthogonal to IP and addressing. 3. NAT (as in transparent packet modification to rewrite addresses) is utterly idiotic. Ephemeral, anonymous address allocation with inbound filtering is smart, but transparently rewriting packets to do that is one of the dumbest possible ways prone to horrible compatibility and ossification issues as has been proven empirically. [1]…

Are you a network engineer?

Re: Why IPv6 is so complicated

#298

Post by amelius »

> Just adding bits to the address isn't as simple as it seems.

They said the same in Y2K, and turned out that people were able to extend their date fields and the systems ran just fine.

Re: Why IPv6 is so complicated

#299

Post by zadikian »

I disagree that it would've been just as hard anyway. The people who say "I just wanted v4 with more bits" have a point that most of these arguments completely ignore, but this one touches on it:

  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.
The practical use would've been going all-in on those, making it as easy as possible for users to switch. But instead, the default way of using v6 was those new addresses, also SLAAC and no NAT, and 6to4 was bolted on in a way that never worked very well.

The thing is, their objective wasn't just to add more bits, it was to defrag the old v4 routes. If you did it the "just add more bits" way, once everyone is on v6 but with the old v4 /32s, the new address space for sale is underneath those. Maybe there'd be a way to defrag afterwards in a separate effort.

Re: Why IPv6 is so complicated

#300

Post by VoodooJuJu »

evilmonkey19 wrote: post #269

Personally, i feel it is complicated because ISPs are highly afraid of trying it. I understand that such novel technology would be risky to use. But after 20+ years there are still many countries, like Spain, which are barely using it. After that much time has passed, it is already well battle-tested. At this point, you don't want to make the move either because you are too afraid of anything or you have commercial r…

[dead]
Post reply on HN