From: Linus Torvalds <torvalds@linux-foundation.org> To: linux-kernel@vger.kernel.org Subject: [RFC] Remove IPv4 support from kernel, effective next merge window Date: Sat, 15 Aug 2025 10:42:00 -0700 Message-ID: <20250815-drop-ipv4@linux-foundation.org>  Hey folks,  After yet another deeply technical and entirely calm discussion about HRT (High-Resolution Timers) that somehow devolved into 200+ replies, personal insults, and at least one GIF of a raccoon, I have decided it’s time to take drastic measures.  Effective next merge window, we will be removing IPv4 support from the kernel. This will both (a) resolve the maintainers’ scheduling disputes, and (b) force the world into the IPV6 utopia we were promised back in 1998.  If you need IPv4 after this point, you can either:  run an ancient kernel from before the change (good luck with the bugs), or rewrite your applications to use IPv6 and learn to love colons in your addresses. Yes, I realize this will break roughly *everything *. No, I don’t care. I have already switched all my machines to IPv6-only, except for the toaster, which unfortunately still insists on using a 192. 168. x. x address. The toaster will be replaced.  If you disagree with this decision, I suggest you take it up with the HRT maintainers. But please keep it civil this time. (Or at least keep the raccoon GIFs under 1MB.)  - Linus

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[–] 131 points 7 months ago (1 child)
  • [–] 71 points 7 months ago

    Now that's some April Fools trolling done right.

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  • [–] 48 points 7 months ago (7 children)

    Honestly, I get this is a joke...but it unironically wouldn't impact me, I run single stack v6, so let's do it. I'll grab some popcorn

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  • [–] 18 points 7 months ago (6 children)

    Isn't like 50% of the internet broken for you if you're only running IPv6? It seems like so many websites , especially small ones, still aren't setting up v6 addresses

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  • [–] 21 points 7 months ago (3 children)

    Small ones are actually often better than big ones. I have a love hate relationship with cloudflare, they contribute to internet centralization but it IPv6 enables so many sites transparently and they only let you turn it off if you're an enterprise customer. So some guy using free cloudflare has IPv6 but not discord, ironic. That being said I have NAT64+DNS64 which lets me access the remaining legacy v4 services without having v4 on my network or devices. Although according to my firewall stats over 90% of my traffic is v6 native, the remainder is NAT64. Honestly the only services I use on a regular basis which don't work if I disable NAT64, discord, steam, and my bank. Everything else I use is v6 native, YT, Crunchyroll, lemmy (this instance), even steam downloads (just not login ironically).

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  • [–] 4 points 7 months ago (2 children)

    I tried to do this but am too old, too dumb, or a little bit of both. Shine on my dude, if there's any resources you found particularly helpful I'd love to see them. Got as far as getting an address from my isp but couldn't even ping it x(

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  • [–] 1 point 7 months ago (1 child)

    Hmmmm, I'm not sure I can think of any super good resources off the top of my head but I'll let you know if I think of any. That's kind of weird though, going IPv6 only is one thing but getting an address and a working connection is often transparent and automated unless you have a 3rd party (non-ISP provided) router.

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  • [+] [S] 83 points 7 months ago* (3 children)
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    [–] 55 points 7 months ago (11 children)

    God I fucking wish. I hate ipv6 but I hate this split world even more. Nothing but headaches.

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  • [–] 34 points 7 months ago (10 children)

    It may be inevitable, but if you wonder why ipv6 has been slow to adopt, it's because no one want to type in 32 alphanumeric digits for every single device, every time...

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  • [–] 14 points 7 months ago* (1 child)

    it’s because no one want to type in 32 alphanumeric digits for every single device, every time…

    Use DNS; I almost never type in an IP manually. You can also make short IPv6 addresses that are just the prefix and a bunch of zeros using '::' followed by one (or more) characters.

    Something like:

    2001:0DB8::1

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  • [–] 10 points 7 months ago (2 children)

    I mean I did say I hate ipv6...

    But seriously, I think it has more to do with it's slightly different, easier for ISPs to just add another NAT layer or whatever instead of learn the minor differences.

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  • [–] 3 points 7 months ago (1 child)

    I’m slowly moving in the direction and have learned a lot, but in my home network, all my devices get a bunch of IPs and services seem to choose at random the IP to listen on. My ISP changes my prefix at random. Devices don’t register in DNS. So even if I use the ULA it’s a lot of fucking typing.

    I also had this thing for a while where the MAC of a bhyve VM would change at boot so even the ULA changed. That fucked me for a while.

    Opnsense lets me create aliases allowing me to create firewall rules, so at least that works now… kinda. But i haven’t figured out privacy extensions.

    So yes, you’re right, 32 digits is a lot to keep in mind.

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  • [–] 25 points 7 months ago (4 children)

    Finally some welcome news. I'm tired of simple easy to understand addressing.

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  • [–] 35 points 7 months ago* (1 child)

    High Resolution Timers aren't even the most controversial HRT.

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  • [–] 33 points 7 months ago (7 children)

    On this day of global reconciliation, they should split the difference and go for ipv5.

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  • [–] 14 points 7 months ago (3 children)

    You mean IPvV?

    I prefer the combination of IPv4 and IPv6 as a Dual Stack, call it IPvX.

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  • [–] 16 points 7 months ago (1 child)
  • [–] 16 points 7 months ago

    I really gotta see this racoon gif

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  • [–] 13 points 7 months ago*

    Damn, you didn't even need to fake it, it's already happening: https://lore.kernel.org/lkml/20260401074509.1897527-1-dwmw2@infradead.org/

    Sure it's still just a joke, but there is a follow up:

    The date notwithstanding, I do actually think we should do most of this for real.

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  • [–] 10 points 7 months ago (1 child)

    If we magically got rid of IPv4, I do wonder if the world would decay to a state of utter chaos like the tabloids were touting for Y2K

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  • [–] 2 points 7 months ago

    The amount of stuff that supports ipv6 is huge, however as most ISPs still don't know how or want to know how to support that would be the problem. So the internet would be fine apart from a couple of sites, but I'd guess 50-80% of home/business connections would fail.

    However most mobile carriers are ipv6 native or close to it, so everyone can get on Facebook and tiktok

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  • [–] 8 points 7 months ago
    [–] 7 points 7 months ago (1 child)

    Maybe we drop ethernet all together and go back to tokenring?

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  • [–] 7 points 7 months ago

    Odd day for him to post this.....

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  • [–] 7 points 7 months ago

    The internet is just a fad anyway

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  • [–] 28 points 7 months ago (1 child)

    ipv4 does not deserve the hate it gets. The congestion caused by the small number of ipv4 addresses is actually really good for privacy, and makes ip based tracking very difficult.

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  • [–] 5 points 7 months ago

    I was hoping they drop TCP/IP scam finally... But no. The only network protocole you need is rina.
    Many have already make the step, learn about it right now to be ready for the futur.

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  • [–] 5 points 7 months ago (2 children)

    You did check today's date?

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  • [–] 3 points 7 months ago

    Aproofoools

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  • [–] 3 points 7 months ago
    [–] 8 points 7 months ago (3 children)

    How can anyone even be bothered doing 1st April anymore with everything going on?

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  • [–] 1 point 7 months ago (1 child)

    Sounds like a Microslop Copilot decision.

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  • 7 comments in c/linux@sh.itjust.works view that post
    [–] 11 points 7 months ago

    Happy 1st of April

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  • [–] 7 points 7 months ago

    IPv2 was more than sufficient, anything beyond that was lunacy.

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  • [+] 5 points 7 months ago (4 children)
  • [–] [S] 2 points 7 months ago (3 children)

    I've never been able to quote and get spoiler to work fully, I think the 2 are just incompatible with each other, best I get is this partial working one where closed it's quoted and when you open it it goes outside the quote

    Yes, but you also sent it to a .ml comm, soo it came here ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

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  • [+] 3 points 7 months ago (1 child)
  • [–] [S] 2 points 7 months ago*

    !linux@programming.dev is the primary one I contribute too as well as primary for my .ml crossposting

    But, where possible, I have identified secondary comms to crosspost to. The sh.itjust.works one is the next largest off-world off-ml linux comm that isn't programming.dev

    I don't really check for active mods, if it becomes an issue for a comm I usually just request to be made a mod at some point

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  • [+] 3 points 7 months ago (1 child)
  • [–] [S] 2 points 7 months ago

    Lol no no, they had just posted to both the .ml linux comm and !linux@programming.dev

    I crosspost content from .ml as part of boycott/protest efforts:

    Why am I cross-posting .ml content?

    I cross-post from .ml to the nearest relevant non-.ml comm to reduce the influence of .ml comms and indirectly, the instance as a whole, to help vitilize non-.ml comms and make it an easier decision for other instance admins to defederate because one key reason I identified that admins don't want to defederate is because .ml still has some very large comms and some active niche comms.

    Megathread on the issue

    Some highlights from the link:

    .ml admin, Nutomics continued transphobia https://lemmy.world/post/29222558 The original transphobic Comment from Nutomic: https://lemmy.world/post/18236068

    "If you don't support Russia then you just don't understand geopolitics" ~dessalines, .ml admin, dev https://lemmy.world/post/27352415

    "Don't worry guys, the Uyghur Genocide was REALLY just birth control! ~dessalines, .ml admin, dev https://lemmy.world/post/30580167

    "See! nobody died IN Tiananmen Square, just AROUND it, so it doesn't count!!" ~ Davel, .ml admin https://lemmy.world/post/30673342

    "NK is actually good and anything counter to that is Western propaganda!" ~dessalines, .ml admin, dev https://lemmy.world/post/31595035

    General negative sentiment to other instances who haven't "seen the way" yet ~davel, .ml admin https://lemmy.world/post/27426510

    And so so much documentation on clear heavy handed censorship and bias also on the link. So much I can't even put them all here because this comment would be really long.

    I believe the behavior of its admins (the main admins are Lemmy devs) does harm to the overall growth of the Lemmy-verse and maybe even the Thrediverse (since Lemmy kinda kicked off the Thrediverse) because of its association with the devs of Lemmy and their insistence to use .ml as their personal political platform to spread harmful propaganda

    On the outside, bringing up Lemmy frequently leads to comments like "Lemmy? Isn't that the place with a bunch of tankies?" Or "Tried Lemmy, but found it full of pro Russia crap so I left". The best way forward from that I see is to either widely defederate from .ml like the rest of the Triad, or pressure them to put a fair and unbiased as possible admin team.

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