New patches allow building Linux IPv6-only

https://www.phoronix.com/news/Linux-IPv6-IPv4-Legacy-Knobs

by Bender • 4 months ago

121 188 4 months ago

As it should. Date notwithstanding, I would actually enjoy if there was a manually induced latency penalty for "legacy IP" that needs to be manually turned off on Linux. I know some people don't care at all, but the internet was made to be addressable. IPv6 is the only shot we have to go back to that.

nslsm• 4 months ago

This reminds me of the ways the governments screw over people to force them to do things they don’t want to.

lxgr7• 4 months ago

Annoying things such as paying taxes, recycling/not polluting etc.?

Some things really can only be solved via central coordination, as there is no natural game-theoretic/purely economic path from one local minimum to another. Being able to dig a small trench and letting gravity and water do the rest is great, but sometimes you do need a pump.

I'm not convinced that IPv6 is such a case, but if it is, that's exactly the type of thing governments are much better at than markets.

huijzer• 4 months ago

Please no. I used to have a Dutch ISP a few months ago that did not support IPv6 yet. (Odido. Same ISP that leaked my data in a big hack.)

jeroenhd• 4 months ago

Odido is the cheapest ISP for a reason. They refuse to implement anything that isn't strictly required.

Perhaps implementing an Odido tax might actually make Odido care enough to throw the switch on IPv6. They bought 2a02:4240::/32, they just refuse to make use of it.

Sanzig3• 4 months ago

Canadian ISPs are also extremely far behind on IPv6. Bell is the largest ISPs in the country and they still don't have IPv6. I'm with one of their wholly owned subsidiaries (EBOX) which offers static /56 allocations, but good luck trying to find anyone in tech support who understands WTF you're talking about.

everdrive3• 4 months ago

- I don't want my interfaces to have multiple IP addresses

- I don't want my devices to have public, discoverable IPs

- I like NAT and it works fine

- I don't want to use dynamic DNS just so I have set up a single home server without my ISP rotating my /64 for no reason (and no SLAAC is not an answer because I don't want multiple addresses per interface)

- I don't need an entire /48 for my home network

IPv6 won't help the internet "be addressable." Almost everyone is moving towards centralized services, and almost no one is running home servers. IPv4 is not what is holding this back.

doubled1122• 4 months ago

I recently changed ISPs and have IPv6 for the first time. I mostly felt the same way, but have learned to get over it. Some things took some getting used to.

An "ip address show" is messy with so many addresses.

Those public IPs are randomized on most devices, so one is created and more static but goes mostly unused. The randomly generated IPs aren't useful inbound for long. I don't think you could brute force scan that kind of address space, and the address used to connect to the Internet will be different in a few hours.

Having a public address doesn't worry me. At home I have a firewall at the edge. It is set to block everything incoming. Hosts have firewalls too. They also block everything. Back in the day, my PC got a real public IP too.

NAT really is nice for keeping internal/external separate mentally.

I'm lucky enough my current ISP does not rotate my IPv6 range. This, ironically, means I no longer need dynamic DNS. My IPv4 address changes daily.

A residential account usually gets a /56, what are you talking about? Nowhere near a /48! (I'm just being funny here...)

There are reasons to need direct connectivity that aren't hosting a server. Voice and video calls no longer need TURN/STUN. A bunch of workarounds required for online gaming become unnecessary. Be creative.

t0mas88• 4 months ago

IPv4 is not holding back home setups, nobody cares about NAT at home.

The place where it hurts is small VPSs, from AWS to mom and pop hosters, the cost of addresses is becoming significant compared to low cost VPSs.

Guvante3• 4 months ago

NAT only matters in so far as you don't technically need a firewall to block incoming traffic since if it fails a NAT lookup you know to drop the traffic.

But from a security standpoint you can just do the same tracking for the same result. That is just technically a firewall at that point.

qalmakka• 4 months ago

NAT is arguably a very broken solution.IPv4 isn't meant to be doing address translation, period. NAT creates all sorts of issues because in the end you're still pretending all communications are end to end, just with a proxy. We had to invent STUN and all sorts of hole punching techniques just to make things work decently, but they are lacking and have lots of issues we can't fix without changing IPv4. I do see why some people may like it, but it isn't a security measure and there are like a billion different ways to have better, more reliable security with IPv6. The "I don't want my devices to have public, discoverable IPs" is moot when you have literally billions of addresses assigned to you. with the /48 your ISP is supposed to assign you you may have 4 billion devices connected, each one with a set of 281 trillion unique addresses. You could randomly pick an IP per TCP/UDP connection and not exhaust them in _centuries_. The whole argument is kind of moot IMHO, we have ways to do privacy on top of IPv6 that don't require fucking up your network stack and having rendezvous servers setting that up.

We may also argue that NAT basically forces you to rely on cloud services - even doing a basic peer to peer VoIP call is a poor experience as soon as you have 2 layers of NAT. We had to move to centralised services because IPv4 made hosting your own content extremely hard, causing little interest in symmetrical DSL/fiber, leading to less interest into ensuring peer to peer connections between consumers are fast enough, which lead to the rise of cloud and so on. I truly believe that the Internet would be way different today if people could just access their computers from anywhere back in the '00s without having to know networking

Sanzig3• 4 months ago

Why don't you want every device to have a public IP? There seems to be a perception that this is somehow insecure, but the default configuration of any router is to firewall everything. And one small bonus of the huge size of a /64 is that port scanning is not feasible, unlike in the old days when you could trivially scan a whole IPv4 /24 of a company that forgot to configure their firewall.

NAT may work fine for your setup, but it can be a huge headache for some users, especially users on CGNAT. How many years of human effort have gone towards unnecessary NAT workarounds? With IPv6, if you want a peer-to-peer connection between firewalled peers, you do a quick UDP hole punch and you're done - since everything has a unique IP, you don't even need to worry about remapping port numbers.

Your ISP shouldn't be rotating your /64, although unfortunately many do since they are still IPv4-brained when it comes to prefix assignment. Best practice is to assign a static /56 per customer, although admittedly this isn't always followed.

And if you don't need a /48... don't use it? 99.99% of home customers will just automatically use the first /64 in the block, and that's totally fine. There's a ton of address space available, there's no drawback to giving every customer a /56 or even a /48.

knorker4• 4 months ago

So run fc00::/7 addresses with IPv6 NAT.

That addresses all of your concerns, and you have that option.

UltraSane3• 4 months ago

NAT is a horrible, HORRIBLE hack that makes everything in networking much more complicated. IP networking is very elegant when everyone is using globally unique addresses and a ugly mess when Carrier NAT is used.

bigstrat2003• 4 months ago

NAT demonstrably does not work fine. We have piles of ugly hacks (STUN, etc) that exist only because NAT does. If you really want to keep NAT then nothing stops you from running it on IPv6, but the rest of us shouldn't suffer because of your network design goals.

blueflow• 4 months ago

I like NAT

I'm in favor of having society overrule you. NAT is a horrible kludge and not okay. Never was.

throwaway27448• 4 months ago

How is a public address any worse than NAT? You can always choose to not respond.

zdp72• 4 months ago

Maybe you don't need the addresses, but there are other advantages. If we made the move, I suspect we could give you the experience you want and the one I want. I personally do want to host my own services. My phone is configured to send my pictures to Google and my personal NAS. Centralized services mean you have to trust that provider. These days I don't. I intend to leave centralized services so I know my content isn't training AI or the doorbell isn't spying on me or my neighbors. But, no instead we should force everyone to share the same IP addresses and run less efficient routing.

sidewndr46• 4 months ago

Why, so you can inflict some personal pain on people without IPv6 access?

lxgr7• 4 months ago

Surely IPv6 support will spontaneously materialize on their networks once their pain becomes big enough!

miyuru2• 4 months ago

I am running IPv6 only servers, and I think it's fair that v4 only people feel the same pain some time in the future.

kevvok• 4 months ago

It’s not implemented in the Linux kernel, but the latency penalty you’re describing is part of the “Happy Eyeballs” algorithm: https://en.wikipedia.org/wiki/Happy_Eyeballs

apitman• 4 months ago

As sad as it makes me to admit, I don't think IPv6 is ever going to happen without government intervention. Adoption is flat at under 50% over the past year. IPv6 doesn't benefit big tech. SNI routing and NAT work pretty well for centralized platforms. AWS will gladly rent us IPv4 addresses until the end of time.

toast0• 4 months ago

IPv6 doesn't benefit big tech.

It does, and big tech has largely adopted IPv6.

For users with IPv6, the v6 path is often less constrained than then v4 path. Serving data faster/more consistently is of benefit to big tech. For a lot of users, v4 and v6 routing are different, which is also helpful for big tech. If you have two paths to the server (and happy eyeballs or something), you have more resiliance to routing issues.

Clouds are slow on v6, but CDNs are not. Adoption on eyeball networks has been very slow, and it's unlikely to speed up much, IMHO. The benefits of v6 for ISPs are not that big for established serviced with large v4 pools. For ISPs running CGNAT, more v6 means less CGNAT and CGNAT is a lot more expensive than plain ip routing. (Doesn't mean all CGNAT providers run v6, but it's an incentive).

zekica6• 4 months ago

SNI routing is such a bad way to do what should be L3 problem that people implemented PROXY protocol to send information about user's endpoint address without doing MITM.

Dagger25• 4 months ago

The Internet itself is growing, so "50%" does still represent a growing number of users. Also Google's stats are missing half a billion v6 users from China.

traderj0e4• 4 months ago

Another way to do ipv6 without government intervention is to make it 1. actually what people want, just v4 with more bits 2. have a reasonable migration path from v4. They made something overcomplicated that disregards all existing users, and now they act like this was the only possible way to avoid address exhaustion and it's everyone's obligation to switch. Even if the govt successfully forced v6, it'd be a downgrade.

nurettin• 4 months ago

enjoy if there was a manually induced latency penalty for "legacy IP" that needs to be manually turned off on Linux

That sounds so bad, it probably will be a windows feature.

hulitu2• 4 months ago

I would actually enjoy if there was a manually induced latency penalty for "legacy IP" that needs to be manually turned off on Linux

Use the source, Luke. Why not start with yourself ?

petcat• 4 months ago

It will be a neat experiment, but I think most software will break and will remain broken indefinitely and then people will turn to LLMs to try to automate fixing all of it and that will turn into a mess just due to the sheer amount of changes required with little scrutiny.

gear54rus• 4 months ago

Perhaps it's time to submit patches that allow building it without IPv6 instead. Countless hours of configuration meddling will be saved.

zamadatix3• 4 months ago

Not sure if you're taking the piss or just missed it but allowing build with either protocol alone is one of the genuine ideas in this joke:

Yeah. The date notwithstanding, I do actually think we should do most of this for real.
Maybe we don't get away with the actual deprecation and the warnings on use just yet, and maybe we won't even get away with calling the config option CONFIG_LEGACY_IP, although I would genuinely like to see us moving consistently towards saying "Legacy IP" instead of "IPv4" everywhere.
But we should clean up the separation of CONFIG_INET and CONFIG_IPV[64] and make it possible to build with either protocol alone.

Daegalus• 4 months ago

great, now can we convince the rest of the internet to start adding AAAA records and ipv6 endpoints for things. Github is still a nightmare to use DNS64 and NAT64 to access those from IPv6 only machines.

Or all the Container based stuff that still falls flat with ipv6 only modes. Docker still shits the bed if you dont give it ipv4 unless you do a lot of manual overrides to things. A bunch of Envoy based gateway proxies fail on internal ipv6 resources in a k8s cluster that runs on ARM64.

There is just a bunch of nonsense you have to deal with if you choose the ipv6-only route

Dont get me started on CDNs like Bunny or Load Balancers as a service like those from Hetzner, UpCloud, etc that don't work with ipv6 origins.

Source: Trying to run a ipv6 only self-hosted box on hetzner.

mhitza• 4 months ago

I've tried to run an IPv6 only box on Hetzner 2-3 years ago. Didn't have a problem with the platform, but with RedHat because subscription-manager didn't work over a IPv6-only stack.

tialaramex• 4 months ago

When I accidentally had IPv6 only for a new Windows box it was very apparent what was a priority (worked regardless) and what wasn't important (only began working once I had IPv4 and everything fixed too).

Baked in advertising? Works with any network. The option to turn off the baked in advertising? That needs IPv4.

PennRobotics• 4 months ago

Around the same time, I think the Photoprism image also didn't work on IPv6 because of Traefik

Macha• 4 months ago

I honestly think GitHub and AWS are the two biggest blockers to IPv6 left. Sure your public web servers might need IPv4 for a long while yet, but all these backend microservices and CI builds etc could all be v6 only, except they need to pull stuff from GitHub or certain AWS services.

Sanzig3• 4 months ago

It's particularly aggravating with AWS, since they charge for IPv4 addresses yet many of their services aren't IPv6 capable.

CookieCrisp• 4 months ago

We’re so close guys! Another 25 years and we might almost be there!

orangeboats• 4 months ago

It's already the major protocol in many countries. A decade ago people were laughing, saying IPv6 will never break 10% adoption. Now it's 50% and somehow people are still making the same joke. Are we insidiously shifting the goalpost somehow?

I don't know 'bout you but ots of services are confident enough in the technology to allow IPv6-only as an option, see eg. Hertzner.

At this point one has to be borderline delusional to think IPv6 is only viable in another 25 years.

porridgeraisin• 4 months ago

I suppose this will lead to a classic torvalds rant. I will be watching r/linusrants

zamadatix3• 4 months ago

Good stuff (both the joke and the genuine proposal of splitting the config options for IPv4 and IPv6).

bornfreddy2• 4 months ago

IPv6 vs. 4 is like Python 3 vs. 2, just worse.

lxgr7• 4 months ago

And IPv6 vs v4 discussions are just like Python 3 vs. 2 discussions: Often much more annoying than just getting it over with and switching.

patmorgan232• 4 months ago

This. Sure there are still some applications that might be difficult to v6 enable, so either patch it or use one of the myriad of options to give it a v6 front end.

zadikian10• 4 months ago

It would've been less annoying to not do a breaking change from Py2 to 3. JS never had a breaking change like that.

craftkiller6• 4 months ago

There are genuine improvements in IPv6 aside from the abundance of addresses. The two that immediately come to my mind are:

1. SLAAC means routers no longer need to keep a record of each client on the network. With DHCP, the router had to maintain a table of which addresses had been assigned and getting an address involved 2-way communication. With SLAAC the router just periodically broadcasts the prefix to the network and any device that wants an address can just listen to that broadcast and assign themselves an address within that prefix without having to inform the router and without the router needing to maintain a table of assigned addresses. (2-way communication is still possible since devices can solicit a broadcast but it is not necessary)

2. With IPv6, middleboxes are no longer allowed to fragment packets. The only device that can fragment a packet is the original sender. If any segment along the path has a lower MTU than the size of the packet, the original sender is notified and then they can fragment the packet.

hulitu2• 4 months ago

Python 3.7 or Python 3.8 ? /s

1970-01-01• 4 months ago

The best pranks are the ones that succeed to rattle an individual. Build it!

ThrowawayTestr• 4 months ago

When I was in grade school I did a presentation on ipv6 and how it was the future of the Internet. That was like 20 years ago.

iamnothere10• 4 months ago

This may be a “joke”, but it’s disturbing to see people clamoring to deny others their freedom in a FOSS context.

Want to use IPv6? Fine. But don’t try to remove v4 support from people who have built stable networks around it.

You won’t be able to force the world to switch to IPv6 with tricks like this, any more than you can force old industrial machines to stop using ancient 486es as controllers. There is a lot of old equipment in the world.

IPv6 was built to work alongside v4, and there is no reason to change that.

embedding-shape3• 4 months ago

it’s disturbing to see people clamoring to deny others their freedom in a FOSS context

How does "allow building Linux to be IPv6-only" somehow "deny others their freedom" exactly? I'm willing to wager most distributions will still be dual v4+v6, but if they aren't, isn't that something for you to bring up with your distribution rather than that the kernel just allows something?

iamnothere10• 4 months ago

Coupling this patch with language about “legacy IP”, along with the follow up comments from the person who submitted the patch, it is clear that the submitter is hostile towards IPv4. I also see hostility towards IPv4 in the comments here and other similar discussions.

I have no problem with allowing optional IPv4 or IPv6 only builds as long as both are kept well-maintained.

budman1• 4 months ago

*removed comment. I didn't know this was an April fools joke. sorry for my lack of a clue....

zamadatix3• 4 months ago

The patchset is an April fools joke and even then it's not going this far.

bladeee• 4 months ago

What? Freedom to opt in or out is good either way.

traderj0e4• 4 months ago

v6 was meant to succeed v4, not work alongside it. https://datatracker.ietf.org/doc/html/rfc8200#section-1

knorker4• 4 months ago

I would like this option, to make it easier to run a CI environment truly IPv6-only. As in socket() to create a v4 socket should fail.

seccomp could only do this partially, in that there are other avenues (e.g. io_uring), and I want it to be the case throughout the boot process.

iso16318• 4 months ago

Creating a v4 socket should map to a v6 address lower down, making v6 transparent to v4 only applications.

Incipient• 4 months ago

The main thing I don't like is type-ability. Even now I type in 192.168.1.14 to connect to my mates computer to play satisfactory. No way in heck am I trying in an ip6!

patmorgan232• 4 months ago

Hmmmm maybe someone should come up with a SYSTEM to organize NAMES for ips, maybe using hierarchical DOMAINs.... Oh wait.

gertop• 4 months ago

Your bad attempt at humor makes it quite clear that you've never dealt with network engineering or administrating to any extent.

Admitting that ipv6 has some downsides, however minor they may seem to you, won't hurt your quest to render ipv4 obsolete.

In fact being less insufferable is how you win people to your causes, not by laughing at their genuine albeit minor issues.

matthews3• 4 months ago

We could abbreviate that to SND!

bpavuk• 4 months ago

how about just having zeroconf on and using .local domains?

vel0city5• 4 months ago

Why not just type in "mates-pc" and have functional mDNS and not have to memorize a bunch of numbers?

Why not just expect your OS's DNS setup to actually just work?

IshKebab3• 4 months ago

Because mDNS usually doesn't work and just expecting it to work doesn't change that?

Dylan168072• 4 months ago

No way in heck are you typing fd00::d or similar? Why not?

password43212• 4 months ago

I recently learned I can skip middle .0's in IPv4, no more 192.168's for me it's 10[.0.0]'s going forward.

dpc_01234• 4 months ago

I wish I had your problems. :D . Problems that are really only a mild inconvenience, and can be solved with a single line in hosts file.

My biggest and possibly only problem preventing me from going IPV6-only is that Github doesn't support it, and there's just too much darn software I need to needs Github. (Yes, I know NAT64 exist - it's just extra complexity for something that is not even my problem in the first place).

New patches allow building Linux IPv6-only

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