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Posted by barqawiz 16 hours ago

Google Hits 50% IPv6(blog.apnic.net)
375 points | 384 commentspage 5
PacificSpecific 15 hours ago|
First thing I do on a fresh Linux install is set ipv6 to deactivated. Fixes all my initial Linux install problems. I don't question it, it just works every time.
BadBadJellyBean 15 hours ago||
Something is very wrong with your network then. I never needed to disable IPv6. Maybe you should question it.
inigyou 10 hours ago|||
If your ipv6 internet is broken you should probably turn it off on your router - hosts on the LAN can still communicate using ipv6 link-local, as some apps will want to do.
ash 14 hours ago||||
It is harder to maintain two networks instead of one. Potential problems double. Hacks like RFC8305 "Happy Eyeballs" become a must.
PacificSpecific 15 hours ago|||
Fair enough. I do question it often.

It's a standard Asus router but it's given me a lot of ire. I hate to say it but it's never a problem when I install windows on the same machines

(I'm currently in the process of trying to completely remove windows from my life)

CrLf 15 hours ago|||
There are maybe many buggy routers still out there that reset the IPv6 flow label field when they shouldn't, breaking hash-based load-balancers (the symptom is TCP connections spontaneously reset).

IIRC, a workaround was to prevent Linux from setting this field, or force-reset it on every outbound packet using netfilter.

drewfax 14 hours ago|||
Similar experience. I bought an ASUS router and enabled IPv6. It slowed down everything down. Immediately flashed OpenWrt on it, IPv6 works like charm.

It's usually bad configuration done by the router vendors. It doesn't mean IPv6 is bad.

PacificSpecific 8 hours ago||
Thanks for the info! I'll look into openwrt
xyst 15 hours ago||
[flagged]
CrLf 15 hours ago||
UX issue, and UX issues are often downplayed by engineers, leading to adoption failures.

Another such example is SELinux, which would have prevented so many vulnerabilities from being exploited, but whose poor UX also caused everyone to disable it at install time.

SELinux's UX was significantly improved many years later, but already too late to change ingrained opinions. There are a lot of ingrained opinions about IPv6 too.

inigyou 13 hours ago|||
Conversely it means people who have ISPs that do IPv6 just have IPv6 and don't need to turn it off. Because it just works. The other day my IPv4 was down and I didn't even notice.
CrLf 12 hours ago||
I don't expect any ISP to do IPv6 today and deploy routers with a flow label bug... Those types of bugs no longer go unnoticed.

IPv6-only ISPs might hit other issues, though. They have to bridge to IPv4 somewhere.

Levitating 13 hours ago|||
> SELinux's UX was significantly improved many years later

in what way?

CrLf 13 hours ago||
Most of what people see as "SELinux" is actually the default policy, which started out as way too strict. Then SELinux-enabled distros such as Red Hat moved to a policy that only applies to system services, and leaves user-launched binaries as if SELinux was disabled.

And even for system services, you can disable SELinux for one service (permissive mode) and leave it enabled for the rest.

This has been the case for more than 10 years, but the damage was done. It's now very hard for users even considering learning the basics (which are not hard).

wolvoleo 10 hours ago|
I have it switched off on most networks and servers including my home network. I just don't need it here and I have zero to do with asia.

I wish they had just made an IPv5 though. With e.g. 6 bytes instead of 4. 65535 times the current internet should be plenty. I feel like IPv6 is overengineered and I'm glad it didn't take off yet. I like being able to memorise IP addresses, it really helps testing.

If I ever do switch it on on my home network I'll probably use NAT on the router so I can still keep it exclusively IPv4 internally on the network.

I first learned about IPv6 when I was studying (1993) and I already felt like it was an overengineered monstrosity back then. They were campaigning like it would be the internet next year. Well that aged well, lol. That's now 33 years ago.

I truly think that if they had made it simpler and more IPv4 compatible we would have been moved over in 2-3 years. But no they had to keep supporting this thing. Well, at this point I'm going to avoid playing ball as long as I can.

lambdaone 9 hours ago||
A changeover to your IPv5 would be just as agonizing as the changeover to IPv6. A system with a larger address space is fundamentally uninteroperable with one with a smaller address space as there is nowhere to put the extra bits in the old protocol. The lack of motivation to move to the new protocol would also be just the same.

And as for memorization: do you actually memorize MAC addresses for your interfaces? The answer is no, you don't, becase ARP handles all that for you. Well, for IPv6, DNS, mDNS and so on handles all that for both your IPv4 and your IPv6 addresses - or should, if you know what you are doing, as memorizing IPs doesn't really scale beyond a few dozen machines.

Yes, IPv6 is overengineered, but it gets the pain of having larger addresses in the packet done once and for all - the odds of needing more than 128 bits in the rest of human history are very small indeed. And if something radically new needs to replace the current IPv6 architecture, which is much more likely, the extra address bits are already there; only 2000::/3 is assigned for public use so far, and the new addresses would fit in the current IPv6 packet format already.

cynicalkane 8 hours ago|||
One big advantage of IPv6 local addresses is that you can pack a lot of semantic information in an address that's easy to remember, plus bits to help with routing and/or firewalling if you need.

DNS and mDNS don't "just work". You don't need but probably really want HA for DNS which is overkill for a homelab user, and you really want a fixed address for that DNS, because who wants to fix issues when you can't even address your services, and you really want your routers to have fixed addresses for the same reasons; you need VLAN and/or Avahi reflecting for mDNS, and if you need firewalling on your LAN, have fun dealing with the fact that mDNS clients prefer GUAs, then IPv4s, then ULAs in that order, by RFC rule, and managing GUAs sensibly when your ISP keeps changing your prefix -- well, IPv6 is almost 30 years old and home/SMB equipment still can't handle that reliably or flexibly, if it even lets you do anything besides assign /64s, and there's nothing stopping your ISP from saying "here just have a single /64, sorry if you wanted to actually use IPv6 for anything clever like having multiple subnets, who would ever want that?" So you say "I'll just use DHCPv6" and it turns out that DHCPv6 kind of sucks and it also turns out many devices don't support that by default or at all, including every single Android and Chrome device, for starters.

IPv6 is full of these design issues where you have a lot of things that are supposed to Just Work, Look It's So Much Simpler Than IPv4, and look at all these address bytes (excuse us while we take 64 of them away for no reason), except you discover that nothing Just Works with anything else in mildly nontrivial cases. You end up on a yak shave only to discover no yak underneath, and you end up just having a broken network while standing in a pile of yak hair. The whole story above is just one example. IPv6 is a migraine in RFC form, and if it weren't that I accidentally bought some expensive IOT devices that are IPv6-only, I'd be happy to never touch it. At this point, it would have been a better time-money tradeoff to have thrown those in the trash as soon as I had seen the problem.

wolvoleo 9 hours ago||||
Yeah but that ridiculous overdimensioning is something I object to. There's more IPs than is needed to give each grain of sand on this planet its whole IPv4-sized internet. That's just overkill.

And the problem seems to be solving itself as the world is turning its back on globalism. China and North Korea already have separated themselves. Iran too. China still uses the same address space but it's not like there's open connectivity with the rest of the world. We'll probably cut off Russia at some point completely as part of some sanction (they've been preparing for that for years), and Europe will break with America if things continue. We'll just have interoperability at a few controlled border points then, like China already does with its great firewall. It'll be easy to do some address translation then.

Ps that's not something I'm necessarily happy about but I do see this trend emerging of every region trying to wall itself off.

vaylian 9 hours ago||
> Yeah but that ridiculous overdimensioning is something I object to. There's more IPs than is needed to give each grain of sand on this planet its whole IPv4-sized internet. That's just overkill.

People also thought that 4 byte wide IPv4 Adresses would be large enough. It's really hard to estimate how much you will need. And because numbers are effectively a free resource, it is better to overestimate.

IPv6 also gives you shortcuts to write addresses. You can abbreviate the longest run of zeroes with `::` and leading zeroes within a hextet can be omitted. This makes IPv6 address notation elastic.

wolvoleo 6 hours ago||
Well considering the 4 bytes were designed in the time of a small research network between defense and universities, it's great foresight that they made it as big as it is. It still runs most of the internet to this day.

But it's not free, after all every packet carries this burden. I know about the annotation but it also makes it very difficult to parse.

mahboi 8 hours ago|||
If ipv5 worked just like ipv4 except with a larger address space, it would be easier than moving to ipv6. I shouldn't have to change my address to switch for example.
eddd-ddde 9 hours ago|||
> I like being able to memorise IP addresses, it really helps testing.

This is even easier with IPv6. At work we have a bunch of test devices, and you calculate the IPv6 from the device's serial number. Simple as that, no memorization at all.

wolvoleo 9 hours ago||
But for an IPv4 device I only have to remember one number :) And nothing to do with a long random serial number.
lambdaone 9 hours ago||
<prefix>::1, <prefix>::2, <prefix>::3, <prefix>::4... exactly how hard can that be?

Or if you're feeling playful, <prefix>::b0d, <prefix>::bed, <prefix>::dad, <prefix>::b1d...

wolvoleo 9 hours ago||
The prefix is too long and it's not the same at every site.

When I'm at a different location, the biggest problem is usually figuring out if they use 192.168.0 or 192.168.1 :)

tcfhgj 9 hours ago||
lucky you, IPV6 indeed uses the same prefix everywhere: fe80::
vaylian 8 hours ago||
Nitpick: The subnet fe80/10 is for link-local addresses (https://en.wikipedia.org/wiki/Link-local_address#IPv6). However, it is not an analog to the RFC 1918 IPv4 subnetworks.

192.168/16 is a private IPv4 subnet (https://en.wikipedia.org/wiki/Private_network#IPv4) and the equivalent for IPv6 is the fd00/8 subnet (RFC 4193).

brewmarche 8 hours ago||
And with ULAs (fd00::/8) you can pick your own prefix. Officially you should pick a random one to prevent collisions when you connect private networks, but you can choose something memorable if you don’t care about that
matja 7 hours ago|||
> I feel like IPv6 is overengineered

In what metrics? IPv6 is more simple to implement than IPv4. In Linux 7.1.1 IPv4 is 84kLOC, IPv6 is 59kLOC.

Hikikomori 9 hours ago|||
An IPv5 would have all the same issues switching over to it. Its been proposed so many times over the years.
zadikian 7 hours ago||
Not necessarily. I've gone down this rabbit hole in another thread, tldr there are alternatives that would've been easier initially but with the downside of leaving the routes fragmented.
Hikikomori 6 hours ago||
Nuh uh.
mahboi 8 hours ago|||
If they're going to make ipv5, might as well make it 8 bytes instead of 4
the_real_cher 9 hours ago||
I dont think its that over engineered for what its capable of.
mahboi 8 hours ago||
That's what overengineered implies, it's capable of things you don't need. The problem with v6 isn't 128-bit addrs though.