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

51–60 of 519 posts

Re: Why IPv6 is so complicated

#51

Post by gucci-on-fleek »

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 simpler than DHCPv4 [3]; IPv6 multicast [4] is much simpler than IGMP [5]; IPv6's lack of NAT simplifies peer-to-peer networking compared to IPv4; ULAs [6] prevent the annoying address conflicts you get with IPv4 [7]; etc.

[0]: https://en.wikipedia.org/wiki/IPv6_packet#Fixed_header

[1]: https://en.wikipedia.org/wiki/IPv4#Packet_structure

[2]: https://en.wikipedia.org/wiki/IPv6_address#Stateless_address...

[3]: https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Pro...

[4]: https://en.wikipedia.org/wiki/IPv6#Multicasting

[5]: https://en.wikipedia.org/wiki/Internet_Group_Management_Prot...

[6]: https://en.wikipedia.org/wiki/Unique_local_address

[7]: https://stackoverflow.com/a/52374482/30512871

Re: Why IPv6 is so complicated

#52

Post by 9dev »

mort96 wrote: post #31
smolder wrote: post #19

It's not. I learned how IPv6 worked SO LONG AGO that I really can't understand remaining confusion.

It's not complicated because you understand it? Okay then

That applies to pretty much any reasonably complex idea. A new system requires effort to understand it. When you've expended that effort, it's not complicated anymore.

I don't understand this sentiment—as if learning IPv4 was enough work on your part, and now you're entitled to networking protocols never changing anymore.

Re: Why IPv6 is so complicated

#53

Post by hnlmorg »

ExoticPearTree wrote: post #37

My first IPv6 implementation was in 2010-2011 (memory a but fuzzy). Carriers supporting BGP over IPv6 were few, websites over IPv6 were also scarce. Fast forward 15 years snd the situation has improved quite dramatically. IPv6 has some quirks that make it harder to digest. - link local gateway address, makes it hard to understand why the subnet does not have a gateway from the ssme address space - privacy extensions:…

The nice thing about NAT is it makes the security model easier to reason about.

By this, I don’t mean it’s more secure, because I know it isn’t. But it is a lot easier to see and to explain what has access to what. And the problem with enterprise is that 80% of the work is explaining to other people, usually non-technical or pseudo-technical decision makers, why your design is safe.

I really do think IPv6 missed a trick by not offering that.

Re: Why IPv6 is so complicated

#54

Post by eqvinox »

muvlon wrote: post #44
9dev wrote: post #20

Earlier quoted context omitted.

> The whole SLAAC/DHCPv6/RA thing is a total clusterfuck. SLAAC is easily the thing I love most about IPv6. It just works. Routers publish advertisements, clients configure themselves. No DHCP server, no address collisions, no worry. What's bugging you about it?

What problem is this actually solving? I've deployed DHCP countless times in all sorts of environments and its "statefulness" was never an issue. Heck, even with SLAAC there's now DAD making it mildly stateful. Don't get me wrong, SLAAC also works fine, but is it solving anything important enough to justify sacrificing 64 entire address bits for?

* privacy addresses are great

* deriving additional addresses for specific functions is great (e.g. XLAT464/CLAT)

* you don't get collisions when you lose your DHCP lease database

* as Brian says, DHCP wasn't quite there yet when IPv6 was designed

* ability to proactively change things by sending different RAs (e.g. router or prefix failover, though these don't work as well as one would hope)

* ability to encode mnemonic information into those 64 bits (when configuring addresses statically)

* optimization for the routing layers in assuming prefixes mostly won't be longer than /64

… and probably 20 others that don't come to mind immediately. I didn't even spend seconds thinking about the ones I listed here.

Re: Why IPv6 is so complicated

#55

Post by XorNot »

9dev wrote: post #34
nottorp wrote: post #26

Earlier quoted context omitted.

> especially with SLAAC Oh no, last time I asked on HN I got 24 to 48 easy steps involving a lot more acronyms than this (please don't repeat them). IPv6 is easy to use only if you let your one router manage everything and you give up control of your home network. Edit: again, please don't help. There have been HNers trying to help before, but my home network is non trivial and all the "easy" autoconfiguration actual…

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.

Re: Why IPv6 is so complicated

#56

Post by 9dev »

muvlon wrote: post #44
9dev wrote: post #20

Earlier quoted context omitted.

> The whole SLAAC/DHCPv6/RA thing is a total clusterfuck. SLAAC is easily the thing I love most about IPv6. It just works. Routers publish advertisements, clients configure themselves. No DHCP server, no address collisions, no worry. What's bugging you about it?

What problem is this actually solving? I've deployed DHCP countless times in all sorts of environments and its "statefulness" was never an issue. Heck, even with SLAAC there's now DAD making it mildly stateful. Don't get me wrong, SLAAC also works fine, but is it solving anything important enough to justify sacrificing 64 entire address bits for?

DHCP requires explicit configuration; it needs a range that hopefully doesn't conflict with any VPN you use; it needs changes if your range ever gets too small; and it's just another moving part really.

With SLAAC, it's just another implementation detail of the protocol that you usually don't have to even think about, because it just works. That is a clear benefit to me.

Re: Why IPv6 is so complicated

#57

Post by harvey9 »

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.

Depends what you are selling and to whom. Meanwhile, India wanted to get a lot of people online and this appears to suit their needs.

Re: Why IPv6 is so complicated

#58

Post by gucci-on-fleek »

hnlmorg wrote: post #53
ExoticPearTree wrote: post #37

My first IPv6 implementation was in 2010-2011 (memory a but fuzzy). Carriers supporting BGP over IPv6 were few, websites over IPv6 were also scarce. Fast forward 15 years snd the situation has improved quite dramatically. IPv6 has some quirks that make it harder to digest. - link local gateway address, makes it hard to understand why the subnet does not have a gateway from the ssme address space - privacy extensions:…

The nice thing about NAT is it makes the security model easier to reason about. By this, I don’t mean it’s more secure, because I know it isn’t. But it is a lot easier to see and to explain what has access to what. And the problem with enterprise is that 80% of the work is explaining to other people, usually non-technical or pseudo-technical decision makers, why your design is safe. I really do think IPv6 missed a tr…

> The nice thing about NAT [...] I really do think IPv6 missed a trick by not offering that

IPv6 supports NAT [0], and nearly all routers make it easy to enable. The primary differences compared to IPv4 is that no-NAT is the default, and that it's more heavily discouraged, but it still works just as well as it does with IPv4.

[0]: In the same way that IPv4 "supports" NAT, meaning that the protocol doesn't officially support it, but it's still possible to implement.

Re: Why IPv6 is so complicated

#59

Post by [deleted] »

eqvinox wrote: post #10
peyton wrote: post #3

What I don’t understand is why coexistence was so important. TFA notes a lot of protocols were in use back then. Also what’s with all the problems? I’ve had RA packets leak across VLANs via firewall misconfigurations, some my fault and some not. I get that people designing internet protocols had a lot to think about, but why am I fighting stuff like this?

> What I don’t understand is why coexistence was so important. Military, corporate, tech... it isn't. (If your people like flag day migrations. It's… "a choice".) But if you have to explain to an end user why some things work and some don't, you're just f'd. And note "coexistence" here means that an end host can implement IPv4 and IPv6 at the same time, without them interacting at all . Imagine if you had to choose b…

[deleted]

Re: Why IPv6 is so complicated

#60

Post by signa11 »

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.

what has _that_ got to do with ipv6 adoption/usage ?

afaics, it probably has more to do with large indian-isp’s f.e. jio adopting ipv6.

Post reply on HN