[no_identd]

We don't live in the world in which IPv6 was a good design. Please avoid acting like IPv6 makes for a good design, because it doesn't.

See apenwarr's by now nearly a decade old blog post "The world in which IPv6 was a good design": https://apenwarr.ca/log/20170810, previous discussions of it here: https://hn.algolia.com/?query=The%20world%20in%20which%20IPv..., as well as the follow up blog post here: https://apenwarr.ca/log/20200708, previous discussions here: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...

And the issues with IP (and by extension, TCP, ignoring the fundamental results from the Delta-T research at Lawrence Livermore keeps biting us all in the ass) whether IPv4 or IPv6 go even deeper, far deeper, than what that blog post already tells us, so here, have this—flawed in some minor aspects, which makes CCIEs burry their head in the sand of denial about the deeper point of it—polemic for dessert: https://web.archive.org/web/20210415054027if_/http://rina.ts...

[ninkendo]

> Please avoid acting like IPv6 makes for a good design, because it doesn't.

Where did I give that impression? I tried my hardest in that post to not make a judgement call one way or the other as to whether it was a good design, only that dual stack fucking sucks.

My followup post in fact, totally agrees with you? https://news.ycombinator.com/item?id=43070286

[immibis]

It's almost exactly just IPv4 with longer addresses. If IPv6 isn't a good design then IPv4 is even worse because of the address shortage.

[aboardRat4]

>It's almost exactly just IPv4 with longer addresses

No it's not. Slaac and NA make it a totally different beast.

If ipv6 only had dhcp6-pd, it would have been "just like ipv4 with longer addresses".

[nottorp]

> No it's not. Slaac and NA make it a totally different beast.

How many ways to be assigned an ipv6 address are there anyway? Two or three too many?

Why should the ISP know what devices I have behind their router?

Considering the amount of enterprise-ish thought that went into ipv6, they thought preciously little of privacy, for example.

[Dagger2]

Their router needs to know what devices are behind it so it can route to them. But if by "their router" you meant "your router"... your ISP doesn't need to know at all. They send all traffic for your prefix to your router, and your router figures it out from there. Your ISP has no idea what devices are involved.

The existence of privacy addresses suggests that some thought was put into this.

[aboardRat4]

There are no more "your routers" for about 10 years. The router is given to you by the ISP, and you don't have the root password for it, you can only reboot it over an APP on your phone.

The prefix is also not delegated to that router, the router does npd proxying, and the ISP only routes the ips which have the corresponding NAs recorded into its database.

[Dagger2]

That's... not how things work in general. It would be possible for an ISP to do that, and I'm sure somebody somewhere does, but they could do the exact same thing on v4 so you don't get to blame v6 for it.

If your ISP runs the default router for your own LAN, they'll have full visibility into it on both v4 and v6. That's just how IP works.

[icedchai]

That's not how it works here. I don't even use my ISPs router. Once the tech left, I swapped it out for a pfsense box. I have a /56 delegated.

[growse]

Well, they also junked useless un-scalable things like broadcast and ARP.

[immibis]

That's the adaptation layer between Ethernet and IP.

Broadcast was renamed to "all nodes multicast". ARP was renamed to Neighbor Discovery.

Slight improvements: ND isn't broadcast, but multicast based on several bits of the IP address. This allows NICs to filter most of the irrelevant ones based on multicast MAC address. And subnet broadcast addresses were removed. There's only local broadcast to your own subnet and not to someone else's subnet, since IPv4 routers found that to be a bad idea and mostly started blocking it anyway.

[j16sdiz]

Meanwhile adding science fiction things like mobile IP.

[immibis]

That's a solution to a problem you don't personally have, and it exists in IPv4 too.

Your cellphone company uses it - or would like to.

It's like SCTP: just because you don't use it doesn't mean there isn't a big group of people who do.

[growse]

Yeah, that one's a bit silly.

[convolvatron]

that's not what this article says. I dug through it, and the main point seems to be 'It would have been beautiful. Except for one problem: it never happened.'

there is nothing really wrong with the design of ipv6 relative to ipv4