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.
- 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.
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.
I don’t want some of my devices to be publicly addressable at all, even if I mess up something at the firewall while updating the rules. NAT provides this by default.
I don’t want a static address either (although static addresses should be freely available to those who want them). Having a rotating IP provides a small privacy benefit. People who have upset other people during an online gaming session will understand; revenge DDoS is not unheard of in the gaming world.
> I don’t want some of my devices to be publicly addressable at all, even if I mess up something at the firewall while updating the rules. NAT provides this by default.
Do you ever connect your laptop to any network other than your home network? For example, public wifi hotspots, hotel wifi, tech conferences, etc? If so, you need to be running a firewall _on your laptop_ anyway because your router is no longer there to save you from the other people on that network.
It's also a good idea even inside your home network, because one compromised device on your network could then lead to all your other firewall-less devices being exploited.
Not every device can run its own firewall. IoT devices, NVR systems, etc should be cordoned off from the internet but typically cannot run their own firewall.
You can have IPv6 firewalls emulate the behavior of NAT so it blocks unsolicited inbound traffic while allowing outbound traffic. If you get a /48 form your ISP you could rotate to a new IP address every second for the rest of your life.
Right, but if you’re messing around as a naive learner it’s easy to accidentally disable that or completely open up an IP or range due to a bad rule. It’s a lot harder to accidentally enable port forwarding on a NAT.
> I don’t want some of my devices to be publicly addressable at all, even if I mess up something at the firewall while updating the rules. NAT provides this by default.
This feels like a strawman. If you are making the sort of change that accidentally disables your IPv6 firewall completely, you could accidentally make a change that exposed IPv4 devices as well (accidentally enabling DMZ, or setting up port forwarding incorrectly for example).
As someone who has done this while tired, it’s a lot easier to accidentally open extra ports to a publicly routable IP (or overbroad range of IPs) than it is to accidentally enable port forwarding or DMZ.
You could accidentally swap ips to one that had a port forward, some applications can ask routers to forward, etc etc. I donmt know how exactly we'd measure the various potential issues but they seem incredibly minor compared to the sheer amount of breakage created by widespread nat.
Great question and my gut is that it makes it that much easier for large, perhaps corporate interests to gain surveillance and control. I'm aware it's possible now, but it really feels like there's some safety in the friction of the possibility that my home devices just switch up IP addresses once in a while.
Like, wouldn't e.g. IPv6 theoretically make "ISP's charging per device in your home" easier, if only a little bit? I know they COULD just do MAC addresses, but still.
You can't correlate the number of addresses with the number of devices because IPv6 temporary addresses exist. If you enable temporary addresses, your computer will periodically randomly generate a new address and switch to it.
I feel like this is a silly narrowing of the problem for normal, retail users. My priority isn't masking "the number of addresses" or devices. My desire is to not have a persistent identifier to correlate all my traffic. The whole idea of temporary addresses fails at this because the network prefix becomes the correlation ID.
I'm not an IPv4 apologist though. Clearly the NAT/DHCP assignments from the ISP are essentially the same risk, with just one shallow layer of pseudo-obscurity. I'd rather have IPv6 and remind myself that my traffic is tagged with my customer ID, one way or another.
Unfortunately, I see no real hope that this will ever be mitigated. Incentives are not aligned for any ISP to actually help mask customer traffic. It seems that onion routing (i.e. Tor) is the best anyone has come up with, and I suspect that in today's world, this has become a net liability for a mundane, privacy-conscious user.
"If you enable" is doing ALL THE HEAVY LIFTING THERE.
Again, my point isn't about what is possible, but what is likely. -- which is MUCH MORE IMPORTANT for the real world.
If we'd started out in an IPv6 world, the defaults would have been "easy to discover unique addresses" and it's reasonable to think that would have made "pay per device" or other negatives that much easier.
Temporary addresses are enabled by default in OSX, windows, android, and iOS. That's what, like 95% of the consumer non-server market? As for Linux, that's going to be up to each distro to decide what their defaults are. It looks like they are _not_ the default on FreeBSD, which makes sense because that OS is primarily targeting servers (even though I use it on my laptop).
> Why don't you want every device to have a public IP?
Suddenly, your smart lightbulb is accessible by everyone. Not a great idea.
> 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.
There is no guarantee with IPv6 that hole punching works. It _usually_ does like with IPv4.
> Suddenly, your smart lightbulb is accessible by everyone. Not a great idea.
The answer here is kinda that Wi-Fi isn't an appropriate networking protocol for lightbulbs (or most other devices that aren't high-bandwidth) in the first place.
Smart devices that aren't high bandwidth (i.e. basically anything other than cameras) and that don't need to be internet accessible outside of a smart home controller should be using one of Z-Wave/Zigbee/Thread/LoRaWAN depending on requirements, but basically never Wi-Fi.
> Why don't you want every device to have a public IP?
Big companies would abuse that beyond belief. Back around the late 90s ISPs wanted to have everyone pay per device on their local networks. NAT was part of what saved us from that.
IMO, IPv6 should have given more consideration to the notation. Sure, hex is "better in every way" except when people need to use it. If we could just send the IPv6 designers back in time, they could have made everyone use integer addresses.
# IPv4 - you can ping this
ping 16843009
# IPv6 - if they hadn't broke it :-(
ping 50129923160737025685877875977879068433
# IPv7 - what could have been :-(
ping 19310386531895462985913581418294584302690104794478241438464910045744047689
> Back around the late 90s ISPs wanted to have everyone pay per device on their local networks. NAT was part of what saved us from that.
But with IPv6 a single device may have multiple addresses, some of which it just changes randomly. So this idea that they'll then know how many devices you have and be able to pay per device isn't really feasible in IPv6.
A single /64 being assigned to your home gives you over 18 quintillion addresses to choose from.
If the ISP really wanted to limit devices they'd rely on only allowing their routers and looking at MAC addresses, but even then one can just put whatever to route through that and boom it's a single device on the ISP's lan.
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
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.
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.
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.
I'm not confused about the NAT / firewall distinction, but it might be nice if my ISP didn't have a constant, precise idea of exactly how many connected devices I owned. Can that be _inferred_ with IPv4? Yes, but it's fuzzier.
The ISP still doesn't know how many devices are connected, because a lot of those devices are using randomized and rotating IPs for their outbound connections.
On Linux, I think the defaults are left up to the distros so there is a chance of a privacy footgun there. Hopefully most distros follow the example set by Apple and Microsoft (a sentence I never thought I would write...)
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.
Only because most people don't know how NAT is hurting them, and because corporations have spent incredible resources on hacking around the problem for when peer to peer is required (essentially only for VoIP latency optimization and gaming).
NAT hurts peer to peer applications much more than cloud services, which are client-server by nature and as such indeed don't care that only outgoing connections are possible.
Even in a NAT-less world, the common advice is to use a firewall rule that disallows incoming connections by default. (And I'd certainly be worried if typical home routers were configured otherwise.) So either way, you'd need the average person to mess with their router configuration, if they want to allow incoming P2P connections without hole-punching tricks. At best, the lack of NAT might save you an address-discovery step.
> the common advice is to use a firewall rule that disallows incoming connections by default.
That's good advice! But firewall hole punching is also significantly easier (and guaranteed to work) compared to NAT hole punching. Address discovery is part of it, but there are various ways to implement a NAT (some inherently un-hole-punch-able) and only really one sane way to do a firewall.
> you'd need the average person to mess with their router configuration,
At least with IPv6, that firewall is likely to exist in the CPE, which sophisticated users can then ideally open ports in (or which can implement UPnP/NAT-PMP or whatever the current name for the "open this port now!!" protocol of the decade is); for CG-NAT, it's often outright impossible.
UPnP has covered a huge percentage of use cases that actual users care about, and those who it doesn't cover are often able to do their own customization.
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.
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).
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.
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.
> They refuse to implement anything strictly required
This describes a lot of businesses ngl.
Bell in Canada is one huge head scratcher. They are one of the largest ISPs here and I can even buy 8 gig internet to my house if I want but they don't support IPv6.
Apparently (according to techs) a lot of ISPs are like that - they said they have everything up and running and even tested to turn on IPv6 but they haven't received the go-ahead.
He mentioned this because marking my connection as a "business" one without changing anything else would allow it to get IPv6 (a /64, bah).
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.
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.
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.
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!
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.
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.
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.
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.
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.
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.
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.
> 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?
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.
> it is clear that the submitter is hostile towards IPv4
But so what? It still doesn't remove v4, in any shape or form, and if that was proposed to the kernel, I'm again fairly confident it'd be rejected.
> I also see hostility towards IPv4 in the comments here and other similar discussions
Ah, yeah that might be. I just saw your comment first, with no context of what you were actually answering, so it kind of looks like you're replying "to the submission", which really isn't denying any freedoms, I guess I was confused about that, my bad. Still, wouldn't it be better to answer directly to those comments, rather than "replying" to an argument/debate that is actually happening elsewhere?
Somehow IPv4 versus IPv6 has become one of those noxious political-technical debates like Android versus Apple or GPL versus BSD/MIT, in which both sides are dug in and think that the other side must be destroyed.
The reason that I don’t like seeing patches like this, even as a “joke”, is that there are real people who would like to see IPv4 removed (possibly by government intervention) in order to achieve their dream of an IPv6 only internet. The whole idea is preposterous, but here we are. It’s about as realistic as banning cars but that doesn’t stop the endless flame wars about it.
Someone has to step in to point out that v4 and v6 were designed to coexist, this is fine, please don’t remove common standards for your personal preferences.
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.
- 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.
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.
I don’t want some of my devices to be publicly addressable at all, even if I mess up something at the firewall while updating the rules. NAT provides this by default.
I don’t want a static address either (although static addresses should be freely available to those who want them). Having a rotating IP provides a small privacy benefit. People who have upset other people during an online gaming session will understand; revenge DDoS is not unheard of in the gaming world.
> I don’t want some of my devices to be publicly addressable at all, even if I mess up something at the firewall while updating the rules. NAT provides this by default.
Do you ever connect your laptop to any network other than your home network? For example, public wifi hotspots, hotel wifi, tech conferences, etc? If so, you need to be running a firewall _on your laptop_ anyway because your router is no longer there to save you from the other people on that network.
It's also a good idea even inside your home network, because one compromised device on your network could then lead to all your other firewall-less devices being exploited.
Not every device can run its own firewall. IoT devices, NVR systems, etc should be cordoned off from the internet but typically cannot run their own firewall.
You can have IPv6 firewalls emulate the behavior of NAT so it blocks unsolicited inbound traffic while allowing outbound traffic. If you get a /48 form your ISP you could rotate to a new IP address every second for the rest of your life.
Right, but if you’re messing around as a naive learner it’s easy to accidentally disable that or completely open up an IP or range due to a bad rule. It’s a lot harder to accidentally enable port forwarding on a NAT.
> It’s a lot harder to accidentally enable port forwarding on a NAT.
It's probably less than three clicks on most home router web UIs.
But you have to specify the not only the exposed port but also the destination address and port which is not easy to do accidentally.
Very hard to make all those clicks accidentally. But anyway I’m talking about pf/iptables rules, not web UIs.
> I don’t want some of my devices to be publicly addressable at all, even if I mess up something at the firewall while updating the rules. NAT provides this by default.
This feels like a strawman. If you are making the sort of change that accidentally disables your IPv6 firewall completely, you could accidentally make a change that exposed IPv4 devices as well (accidentally enabling DMZ, or setting up port forwarding incorrectly for example).
As someone who has done this while tired, it’s a lot easier to accidentally open extra ports to a publicly routable IP (or overbroad range of IPs) than it is to accidentally enable port forwarding or DMZ.
You could accidentally swap ips to one that had a port forward, some applications can ask routers to forward, etc etc. I donmt know how exactly we'd measure the various potential issues but they seem incredibly minor compared to the sheer amount of breakage created by widespread nat.
I don’t have any problems with NAT on my network.
Great question and my gut is that it makes it that much easier for large, perhaps corporate interests to gain surveillance and control. I'm aware it's possible now, but it really feels like there's some safety in the friction of the possibility that my home devices just switch up IP addresses once in a while.
Like, wouldn't e.g. IPv6 theoretically make "ISP's charging per device in your home" easier, if only a little bit? I know they COULD just do MAC addresses, but still.
You can't correlate the number of addresses with the number of devices because IPv6 temporary addresses exist. If you enable temporary addresses, your computer will periodically randomly generate a new address and switch to it.
https://www.rfc-editor.org/rfc/rfc8981.html
I feel like this is a silly narrowing of the problem for normal, retail users. My priority isn't masking "the number of addresses" or devices. My desire is to not have a persistent identifier to correlate all my traffic. The whole idea of temporary addresses fails at this because the network prefix becomes the correlation ID.
I'm not an IPv4 apologist though. Clearly the NAT/DHCP assignments from the ISP are essentially the same risk, with just one shallow layer of pseudo-obscurity. I'd rather have IPv6 and remind myself that my traffic is tagged with my customer ID, one way or another.
Unfortunately, I see no real hope that this will ever be mitigated. Incentives are not aligned for any ISP to actually help mask customer traffic. It seems that onion routing (i.e. Tor) is the best anyone has come up with, and I suspect that in today's world, this has become a net liability for a mundane, privacy-conscious user.
"If you enable" is doing ALL THE HEAVY LIFTING THERE.
Again, my point isn't about what is possible, but what is likely. -- which is MUCH MORE IMPORTANT for the real world.
If we'd started out in an IPv6 world, the defaults would have been "easy to discover unique addresses" and it's reasonable to think that would have made "pay per device" or other negatives that much easier.
Temporary addresses are enabled by default in OSX, windows, android, and iOS. That's what, like 95% of the consumer non-server market? As for Linux, that's going to be up to each distro to decide what their defaults are. It looks like they are _not_ the default on FreeBSD, which makes sense because that OS is primarily targeting servers (even though I use it on my laptop).
and most OS do enable it by default
Many routers don't firewall by default. Lemme check later, but pretty sure my basic ASUS router doesn't either.
> Why don't you want every device to have a public IP?
Suddenly, your smart lightbulb is accessible by everyone. Not a great idea.
> 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.
There is no guarantee with IPv6 that hole punching works. It _usually_ does like with IPv4.
> Suddenly, your smart lightbulb is accessible by everyone. Not a great idea.
The answer here is kinda that Wi-Fi isn't an appropriate networking protocol for lightbulbs (or most other devices that aren't high-bandwidth) in the first place.
Smart devices that aren't high bandwidth (i.e. basically anything other than cameras) and that don't need to be internet accessible outside of a smart home controller should be using one of Z-Wave/Zigbee/Thread/LoRaWAN depending on requirements, but basically never Wi-Fi.
> Suddenly, your smart lightbulb is accessible by everyone. Not a great idea.
That's what your router is for. NAT is just a kludge.
> hollowing can crash the target process if the payload isn't carefully matched to the host process architecture.
So here's the thing. My ISP does _not_ rotate my IPv4 address, but _does_ rotate IPv6. Why? I'll never know.
Anyhow. I'm not confused about NAT vs. firewalling. No one who dislikes IPv6 is confused by this.
> Why don't you want every device to have a public IP?
What would be the advantage in it?
> Why don't you want every device to have a public IP?
Big companies would abuse that beyond belief. Back around the late 90s ISPs wanted to have everyone pay per device on their local networks. NAT was part of what saved us from that.
IMO, IPv6 should have given more consideration to the notation. Sure, hex is "better in every way" except when people need to use it. If we could just send the IPv6 designers back in time, they could have made everyone use integer addresses.
It's simple, unambiguous, and scales infinitely.It's simple, unambiguous, and scales infinitely
This is a joke right? How does it "scale infinitely"? It is clearly ambiguous in your ipv7 example.
> Back around the late 90s ISPs wanted to have everyone pay per device on their local networks. NAT was part of what saved us from that.
But with IPv6 a single device may have multiple addresses, some of which it just changes randomly. So this idea that they'll then know how many devices you have and be able to pay per device isn't really feasible in IPv6.
A single /64 being assigned to your home gives you over 18 quintillion addresses to choose from.
If the ISP really wanted to limit devices they'd rely on only allowing their routers and looking at MAC addresses, but even then one can just put whatever to route through that and boom it's a single device on the ISP's lan.
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
> I like NAT
I'm in favor of having society overrule you. NAT is a horrible kludge and not okay. Never was.
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.
So run fc00::/7 addresses with IPv6 NAT.
That addresses all of your concerns, and you have that option.
But that doesn't allow to bitch about it so - no.
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.
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.
> Having a public address doesn't worry me. At home I have a firewall at the edge. It is set to block everything incoming.
Concern is privacy, not security. Publicly addressable machine is a bit worse for security (IoT anyone?), but it is a lot worse for privacy.
I'm not confused about the NAT / firewall distinction, but it might be nice if my ISP didn't have a constant, precise idea of exactly how many connected devices I owned. Can that be _inferred_ with IPv4? Yes, but it's fuzzier.
Is this solved by the device having between 1 and X randomly generated IPv6 addresses?
Some of my devices have 1, some 2, and some even more. Takes some precision out, at least.
Aren't your home addresses assigned by your local router?
The ISP still doesn't know how many devices are connected, because a lot of those devices are using randomized and rotating IPs for their outbound connections.
You already have a public IP address the only difference is if you have a rotating IP address which is orthogonal to IPv6.
The only difference is most ISPs rotate IPv4 but not IPv6.
Heck IPv6 allows more rotation of IPs since it has larger address spaces.
IPv6 can "leak" MAC addresses of connected devices "behind the firewall" if you don't have the privacy extensions / random addresses in use.
There are a number of footguns for privacy with IPv6 that you need to know enough to avoid.
Privacy extensions are enabled by default on OSX, windows, android, and iOS: https://ipv6.net/guide/mastering-ipv6-a-complete-guide-chapt...
On Linux, I think the defaults are left up to the distros so there is a chance of a privacy footgun there. Hopefully most distros follow the example set by Apple and Microsoft (a sentence I never thought I would write...)
They are now - I'm not sure when they implemented them but I know Windows at least would do some really stupid stuff very early on.
With SLAAC and a random IPv6 you would get at least the same level of privacy. One public IPv4 isn't different from /48 IPv6 network.
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.
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.
> nobody cares about NAT at home.
Only because most people don't know how NAT is hurting them, and because corporations have spent incredible resources on hacking around the problem for when peer to peer is required (essentially only for VoIP latency optimization and gaming).
NAT hurts peer to peer applications much more than cloud services, which are client-server by nature and as such indeed don't care that only outgoing connections are possible.
Even in a NAT-less world, the common advice is to use a firewall rule that disallows incoming connections by default. (And I'd certainly be worried if typical home routers were configured otherwise.) So either way, you'd need the average person to mess with their router configuration, if they want to allow incoming P2P connections without hole-punching tricks. At best, the lack of NAT might save you an address-discovery step.
> the common advice is to use a firewall rule that disallows incoming connections by default.
That's good advice! But firewall hole punching is also significantly easier (and guaranteed to work) compared to NAT hole punching. Address discovery is part of it, but there are various ways to implement a NAT (some inherently un-hole-punch-able) and only really one sane way to do a firewall.
> you'd need the average person to mess with their router configuration,
At least with IPv6, that firewall is likely to exist in the CPE, which sophisticated users can then ideally open ports in (or which can implement UPnP/NAT-PMP or whatever the current name for the "open this port now!!" protocol of the decade is); for CG-NAT, it's often outright impossible.
UPnP has covered a huge percentage of use cases that actual users care about, and those who it doesn't cover are often able to do their own customization.
NAT is hurting anyone who has to use CGNAT and share an IP with a bunch of other people.
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
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.
> 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).
Making IPv4 intentionally laggy would break orgs that depend on ancient gear or SaaS with hardwired v4, for a purist's thrill and outages for users.
> 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.
Why, so you can inflict some personal pain on people without IPv6 access?
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.
Surely IPv6 support will spontaneously materialize on their networks once their pain becomes big enough!
This reminds me of the ways the governments screw over people to force them to do things they don’t want to.
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.
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.)
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.
> They refuse to implement anything strictly required
This describes a lot of businesses ngl.
Bell in Canada is one huge head scratcher. They are one of the largest ISPs here and I can even buy 8 gig internet to my house if I want but they don't support IPv6.
Apparently (according to techs) a lot of ISPs are like that - they said they have everything up and running and even tested to turn on IPv6 but they haven't received the go-ahead.
He mentioned this because marking my connection as a "business" one without changing anything else would allow it to get IPv6 (a /64, bah).
they do use it in their speedtest server.
Probably a requirement from Ookla, so again "They refuse to implement anything that isn't strictly required".
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.
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.
Perhaps it's time to submit patches that allow building it without IPv6 instead. Countless hours of configuration meddling will be saved.
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.
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!
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?
how about just having zeroconf on and using .local domains?
Hmmmm maybe someone should come up with a SYSTEM to organize NAMES for ips, maybe using hierarchical DOMAINs.... Oh wait.
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.
IPv6 vs. 4 is like Python 3 vs. 2, just worse.
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.
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.
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.
Good stuff (both the joke and the genuine proposal of splitting the config options for IPv4 and IPv6).
The best pranks are the ones that succeed to rattle an individual. Build it!
We’re so close guys! Another 25 years and we might almost be there!
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.
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.
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.
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.
Around the same time, I think the Photoprism image also didn't work on IPv6 because of Traefik
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.
It's particularly aggravating with AWS, since they charge for IPv4 addresses yet many of their services aren't IPv6 capable.
I suppose this will lead to a classic torvalds rant. I will be watching r/linusrants
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.
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.
> 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?
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.
> it is clear that the submitter is hostile towards IPv4
But so what? It still doesn't remove v4, in any shape or form, and if that was proposed to the kernel, I'm again fairly confident it'd be rejected.
> I also see hostility towards IPv4 in the comments here and other similar discussions
Ah, yeah that might be. I just saw your comment first, with no context of what you were actually answering, so it kind of looks like you're replying "to the submission", which really isn't denying any freedoms, I guess I was confused about that, my bad. Still, wouldn't it be better to answer directly to those comments, rather than "replying" to an argument/debate that is actually happening elsewhere?
Somehow IPv4 versus IPv6 has become one of those noxious political-technical debates like Android versus Apple or GPL versus BSD/MIT, in which both sides are dug in and think that the other side must be destroyed.
The reason that I don’t like seeing patches like this, even as a “joke”, is that there are real people who would like to see IPv4 removed (possibly by government intervention) in order to achieve their dream of an IPv6 only internet. The whole idea is preposterous, but here we are. It’s about as realistic as banning cars but that doesn’t stop the endless flame wars about it.
Someone has to step in to point out that v4 and v6 were designed to coexist, this is fine, please don’t remove common standards for your personal preferences.
*removed comment. I didn't know this was an April fools joke. sorry for my lack of a clue....
The patchset is an April fools joke and even then it's not going this far.
What? Freedom to opt in or out is good either way.