The Ripe NCC Has Run Out of IPv4 Addresses
ripe.net
ripe.net
1. My home has Verizon fiber. No native IPv6. I have a tunnel for this, but such solutions aren’t going to work for the masses. The other in-region residential provider, Comcast, has great native IPv6 service, but had layer 2 performance issues versus price.
2. At $dayjob I just ordered a circuit from Level3/Centurylink for a branch site. No IP justification form was required if I needed only IPv4 /30. But for dual IPv4 /30 + IPv6 /126, I was required to provide written justification. Shouldn’t this be the other way around? Unencumbered IPv6 for all, with paperwork for IPv4?
EDIT: these are not site allocations, just point-to-point link addresses, hence the /126. Still, I’m being asked to justify IPv6 but not IPv4.
I've heard this pretty often. One day it gets rolled out without any notice, and surprise, you're on V6. Plays havoc.
Uh, unless you're running BGP over this or getting a larger subnet statically routed to you, get a larger prefix. A /48 or /56 is the current recommendation [1] for business end site allocations.
That said, I think the original intent was that such “point-to-point Ethernets” should have been issued /64, but seems /126 is common practice.
* https://www.ripe.net/publications/docs/ripe-690#4-1-2--unnum...
Also another fyi: if you're rolling commodity hw (bcm tridents etc) after a /64 up to /128 you are dipping into another constrained forwarding table - can't fill your box with too many of those.
I can get a /56 even at my apartment just by setting my router to request it.
Only server administrators need to care, and there they have a problem. If you run real IPv4 only: then IPv6 only users can talk to your server no problem and won't even realize anything is happening. If you run IPv6 only there are a lot of IPv4 only users who cannot connect to you. Thus if you run a server it is critical to have a real IPv4 address.
Did you notice the "real" qualifier to IPv4 in that last paragraph? many (most?) IPv4 only users are behind a NAT system such that they cannot run a server anyway. If you are running a IPv4 Server you need an address of the type that RIPE just ran out of. If you are a user you can use a fake IPv4 address and keep on working.
If you are a server administrator you should ensure that all your servers have IPv6 addresses. You should then collect statistics on use. There may be a date in the future where you can suggest to your management that you can cut off [small number]% of your users by going IPv6 only and selling your existing IPv4 address to the highest bidder for $$$. That is a business decision, but once it starts happening it will make headlines, but I wouldn't want to be first. (if you wait too long enough others will have gone IPv6 only that there isn't a real customer cost to being IPv6 only and then the market for IPv4 will disappear - and interesting value maximization problem if you want to play that game)
NAT approaches to bridge IPv6 and IPv4 exist and work as well as IPv4-to-IPv4 NATs, that is to say pretty poorly: but we've long since adjusted the architecture of Internet-enabled software to cope with the flaws, so practically speaking they work just fine.
We've been down a road for a while now of funnelling all of the Internet's services into something-over-HTTP, so running a server might need a public IPv4 address, but as the supplies already assigned to LIRs by the RIPE NCC (and other RIRs) start to dwindle I expect we'll see more services offered whereby you can share an HTTP front end with a bunch of other people, proxied to an IPv6 (or private space) server you run.
A more common approach to reach IPv6 networks from IPv4 ones is tunneling the traffic on top of your existing IPv4 network. This way you become fully addressable and able to reach both networks almost like you would have been able to with a dual stack setup except that the tunnel reduces your MTU because of the tunneling and that you need an remote endpoint with support for both networks that routes packets to your tunnel accordingly.
Using IPv6 only makes it impossible to reach you from an IPv4 only node while still making it easy to reach other IPv4 host from your side using only NAT techniques. Using IPv4 only its unfeasible to reach arbitrary IPv6 hosts using NAT only and a tunnel setup is more or less required to make it work properly.
Not only has CGNAT existed doing this at scale for many years in SE Asia, it commonly happens on cell networks in the US now even, so yes, it’s feasible.
The comparison with DoH is imperfect, certainly, but still probative. DoH does something, today; it protects queries to sites all around the Internet, and doesn't depend on a boil-the-ocean deployment that must occur simultaneously in two directions (from the service operators who must sign their zones and from the end systems which must upgrade and enable DNSSEC). DoH is a relatively young protocol and will, within the next year or two, be almost completely mainstream, a feature of most of the deployed base of browsers. DNSSEC will still be languishing, because we aren't humane enough to drag it out to the yard, rifle in hand, to put it out of its misery.
I'm all for IPv6 but it's not widespread enough to ditch the need for static IPv4 addresses.
Doing this means all IPv4 network addressing headaches vanish internally. Oh there are going to be 260 remote offices instead of 100 like you said at the kick off meeting? No problem, my subnets are easily big enough either way.
And with this approach your budget for the edge reduces over time as more of the network supports IPv6, whereas with a NAT gateway your budget increases as throughput rises.
You do need to be really firm during purchases, if the "IPv6 support" in that shiny new product is actually more of a wishlist item than an actual feature, you're getting a full refund, no second chances. That goes for desk phone (if your outfit still has those), printer/ copiers, IoT devices, and everything.
Putting multiple customers on the same /24 introduces all kinds of issues. Either you leave it open leaving IP's vulnerable to hijacking, or you have to create static ARP and/or MAC entries, and deal with all the hassle of managing that. Presumably, you're describing consumer service where they don't really have to care about your security unlike a business/enterprise level service.
Does this mean we've finally run out of new allocatable IPv4 addresses with the RIRs?
[0]: https://en.wikipedia.org/wiki/Regional_Internet_registry#/me...
Game over IPv4.
I'm wondering how much justification validation they are actually doing, or if something worse is going on.
given the recent corruption allegations with PIR/ICANN, I wouldn't be surprised if it was corruption.
- APNIC ran out
- ARIN ran out
- RIPE NCC just ran out
- AfriNIC is expected to run out in 2020
- LACNIC is expected to run out in May 2020 https://www.lacnic.net/1039/1/lacnic/ipv4-depletion-phases
Theoretically we could have transitioned to IPv6 instead and avoided this hassle, but too many incumbents are dragging their feet on the whole IPv6 issue.
Fingers crossed they don't lol.
But IPv6 prefix delegation doesn't always work if you put your own router behind the ISP box...
However, I also have native ipv6 to the home for as many devices as I want. It's easy to forget that carrier NAT is expensive for ISPs as NAT hardware needs a lot of fast RAM.
This is why many residential ISPs and business haven’t implemented IPv6 yet (well, the later enjoys the false sense of security NAT provides too).
All they needed to do was expand the address space, but it looks like the kitchen sink got thrown in.
Another is that it changes the way you think about IP addresses, with endpoints getting a /64 instead of a single address like you did in IPv4. This allows users to change their IP address for every connection if they want, so if you want to apply policy to them you need to apply it to the entire subnet they are on. Granted, this also happens in IPv4 if you are doing NAT, so it's not really a change for most people.
There are a few other changes to stuff like QoS to better reflect modern practice, but for the most part it's pretty similar. Also, the IP header lost its checksum, as it was basically never useful.
Everyone that I talked to about this seemed to like the change.
End points get /128, it's just that subnets are now /64.
That simply means that endpoints can auto-assign themselves a new /128 because--instead ofhaving only space for 2^8 hosts in the typical /24 subnet of IPv4--there is now space for 2^64 hosts, which makes it unlikely that collisions will occur.
Only if you don't have a clue of IPv4 either.
> with endpoints getting a /64 instead of a single address like you did in IPv4.
That's just wrong. And endpoint gets one address, just as with IPv4 (and can optionally assign additional addresses where address space is available, also just as with IPv4).
What gets a /64 by default is a link, like, an ethernet. Which is also exactly like in IPv4, except, of course, with IPv4 you had shorter/fewer addresses, and thus obviously also smaller prefixes/fewer addresses per link.
> This allows users to change their IP address for every connection if they want, so if you want to apply policy to them you need to apply it to the entire subnet they are on.
Which is also exactly the same as with IPv4. If your LAN has an IPv4 /24, you can also change you address for every connection.
> Granted, this also happens in IPv4 if you are doing NAT, so it's not really a change for most people.
You have it all backwards?! NAT is what makes this impossible for connections to the public internet, in that no matter how you change your RFC1918 address, you keep the same address to the outside world? But that obviously is not a property of IPv4, but of NAT.
SLAAC the router gives you the 64 bit prefix and the host chooses its own 64 bit host address, which can be any address not already in use. With IPv4 you are typically assigned a single IP address via DHCP. While it is true that you are free to ignore the DHCP address assigned to your host and select something else on the same subnet, this is not typical. With SLAAC however it is the norm for the host to figure out its own address, and to leverage the enormous IP space available in IPv6 to change up their source address at will.
Filtering individual hosts by IP has always been leaky, but IPv6 makes it more or less impossible. You have to filter by subnet.
IPv6 does have some braindamage. SLAAC didn't have a way to communicate the local DNS server address to hosts, nor a way for hosts to update the DNS with their selected addresses and hostnames. This is something that has just worked in DHCP for decades and was completely ignored by the IETF. There was some handwaving about mDNS and anycasting but the actual protocol for doing the updates was never nailed down and it ignored the fact that multicast on wireless networks has always been fragile and plagued by hardware/driver issues.
Arguably, it's alive and well for the use case where it actually makes sense: For prefix delegation.
> With IPv4 you are typically assigned a single IP address via DHCP.
Well, sure, and with IPv6 you are "typically assigned a single IPv6 address via SLAAC"!?
I mean, if you are talking about a controlled environment, that's not exactly difficult to achieve, by either using MAC-address based v6 addresses, or by configuring a fixed host suffix on the respective machine, just as you would configure DHCP. If you are talking about random people/devices on your network, neither case prevents them from assigning themselves whatever addresses they please.
> Filtering individual hosts by IP has always been leaky, but IPv6 makes it more or less impossible. You have to filter by subnet.
But that is what you are doing with IPv4 as well? Just because you can't see the individual addresses of individual machines, and thus have no other choice but to block the whole subnet (that is, the NAT gateway address that proxies for it), doesn't mean you aren't blocking whole subnets!?
> SLAAC didn't have a way to communicate the local DNS server address to hosts
Well, yeah, but that's been resolved, as you seem to know.
> nor a way for hosts to update the DNS with their selected addresses and hostnames.
Except it does? If you ask me, it does not make any sense for the DHCP server to update the DNS server anyway: It's the host that owns the host name and that knows where it is reachable, and also a host in principle could be getting its connectivity from anywhere, not just a particular fixed DHCP server. The host should have the credentials for updating its DNS name, should select the address to publish for inbound connections based on its local policy, and then publish that address to the DNS. It makes no sense to tightly couple naming services and connectivity: When my laptop switches from ethernet to LTE, it should just update its DNS name to point to the address it obtained from the LTE provider, and obviously that should not involve the DHCP server of the LTE provider.
Unlike DHCP, SLAAC doesn't assign specific addresses to hosts. It communicates the network prefix via periodic broadcasts, and hosts choose their own addresses within that prefix.
DHCPv6 is used for routers, which need to be given not just an individual address on the local interface but also a prefix that they can hand out to their clients. It's optimized for flows that require a confirmation from the client that it has accepted/reserved the configuration that it's been given.
It is technically possible to use DHCPv6 to hand out IPs to endpoints, but I have not seen any production network in the wild that does this.
As long as they were breaking compatibility, all kinds of details were changed to make things easier on implementers.
Regardless, I don't get your argument. Why would not being able to address all of a given address space be a bad thing? Isn't the whole point to have more address space than will ever by physically possible to need?
Is that not the definition of over-engineering?
Now we just took what we thought we needed, and added a few tens of orders of magnitude.
An average human cell is composed of 100 trillion atoms. [0]
An average human body is composed of 100 trillion cells.
By that we see there are about 10^28 atoms in a human body.
Let’s be conservative, and say the world population for the next fifty years stays under 10 billion (most estimates say closer to 100 years).
That gives us about 10^38 atoms across all human beings on earth.
Why does this matter? Because 2^128 is 3.4 × 10^38.
That’s three IPv6 addresses for each and every atom in all the humans on earth for at least the next 50 years.
If that’s not the definition of overkill, I dunno what is.
[0] https://www.thoughtco.com/how-many-atoms-in-human-cell-60388...
Edit: And if you say the real routable space of IPv6 is only 2^64, then my point still stands. Rather than it being 3 IPs for every atom, it’s still an IP for essentially every cell of every human on earth for the foreseeable future.
My edit I made last night might seem to imply otherwise, but that was due to me being a bit terse with that part and I can’t go back and edit further now.
The whole point of L3 is to provide a layer of routing and aggregation on top of L2. Routing and aggregation requires sparse allocations, so L3 requires more address space than L2 does. L2 is 64 bits for new protocols today (which are supposed to be using EUI-64), so L3 needs to be more than 64 bits.
People would complain loudly if we didn't use a power of two, so here we are at 128 bits.
These are just silly examples, but the point is that we don't yet know what will happen to make us run out of space.
Even if that’s true, that’s about 3x longer than IPv4.
A hundred years ago, computers didn’t exist. Can you imagine how well a network address scheme invented back then would work for our needs?
Why do you presume we can do a better job of predicting what the networking needs of a hundred years from now will be?
Or perhaps you are short sighted. :)
Look at all the drama and effort that we have had to go through over a decade or two to get past IPv4: if we went with "only" 64 bits for addresses, and we miscalculated and ran out again, we would have to go through that all over again.
It's the same reason why the ZFS folks (Jeff Bonwick) designed in 128 bit from the start:
* https://blogs.oracle.com/bonwick/128-bit-storage:-are-you-hi...
> Thus, fully populating a 128-bit storage pool would, literally, require more energy than boiling the oceans.
Very definition of excess as well, so thanks for proving my point!
Except you're skipping over the part about running out at 2^64:
> Some customers already have datasets on the order of a petabyte, or 250 bytes. Thus the 64-bit capacity limit of 264 bytes is only 14 doublings away. Moore's Law for storage predicts that capacity will continue to double every 9-12 months, which means we'll start to hit the 64-bit limit in about a decade.
2^64 bits ought to be enough for anybody. -- jsjohnst
Try reading what you quoted again, nobody is running out yet.
There are a lot of intermediate steps between 2^64 and 2^128! ;)
Really, this has absolutely nothing to do with "over-engineering", as there is absolutely no "engineering" in making the address larger, it adds zero complexity, and it massively simplifies network design because it removes constraints that really complicate the building and maintenance of networks.
Login to a route server and see for yourself.
That makes it even less possible routes then, 248.
The point of this ridiculously large space is that it makes routing tables smaller, because topologically-near areas can be given common prefixes without worrying about address exhaustion.
Designing the IPv6 address space to be filled with devices is about as sensible as designing the DNS system to be filled with domains. Like, instead of allowing for domain names with 63 characters per label, we could have just said DNS names are alphanumeric strings 7 characters long, and you get assigned a random one if you register a domain, to maximize the utilization of the address space. But that would be simply idiotic, because the purpose of that address space is to provide readable names, not to "use all the addresses".
65536.65536.65536.65536.65536.65536.65536.65536
One thing you don't see enough of yet is providers charging for the IPv4 address their customers probably don't need. Those have a real cost, and economics 101 tells us if something has a cost, even a small cost, and you surface that cost to your customers, suddenly they're a lot more interested in helping avoid that cost than they were when you just ate it as part of the service. Plastic carrier bags weren't free back when grocery stories didn't charge for them -- they just absorbed the financial cost and externalised the environmental cost. Charge for the bags and suddenly customers remember they already have a bag, they don't need a bag. Same with IPv4.
Do other cloud providers (Azure, Google Cloud, Digital Ocean) do this?
I feel like the adoption problem is now firmly on "us". Last time I was setting up an internal network, I was afraid of the consequences of using IPv6 internally, so I just didn't. I imagine a lot of people are in the same boat, and they are the stragglers preventing us from turning off IPv4. The big players are ready.
(I will say that jrock.us has worked over IPv6 for almost as long as Google, though. When you only have one computer on the network, IPv6 is not much work.)
If every single incumbent and every single newcomer is dragging their feet on IPv6, maybe, just maybe, the problem isn't every single engineer in the industry, the problem is IPv6.
Theoretically we could have had a straightforward extension of IPv4 to a longer address length and the exact same design, but some architecture astronauts took over the IETF and they think it's more valuable to push their weird redesign of the internet than to actually solve IPv4 address exhaustion.
The situation feels like chicken-and-egg to me. If I had the option to use IPv6 at home, I'd be on it 100%... as-is, there's little motivation to move off of v4 internally since I'd have to NAT/tunnel to get to the v6 internet over Fios. That said, most of my link-local intranet traffic is on the fe80:: network, because that's what avahi and mDNS prefer as answers.
There's still a lot of waste that can be reclaimed before it's game over for IPv4. For just two examples - both Ford Motor Company and Prudential Securities are currently assigned over 16.7 million public IPv4 addresses each.
https://en.wikipedia.org/wiki/List_of_assigned_/8_IPv4_addre...
So do Apple, AT&T, the U.S. Postal Service and others.
Even better would be for Apple to return most of those addresses and only use a handful of /16s for its hosted services like any other business and switch the internal nets to RFC1918.
https://en.wikipedia.org/wiki/IPv4_address_exhaustion#Addres...
Entire networks of computers can share a single public IP address so the 33.5 million public IP addresses supplied by two /8s could last quite a long time. Or we can let Ford sit on them.
EDIT: just found it https://en.wikipedia.org/wiki/List_of_assigned_/8_IPv4_addre...
https://en.wikipedia.org/wiki/IPv4_address_exhaustion#/media...
with some 1M ips given out PER DAY, how long would two /8s last? 4 weeks, or 33 days. That is not "quite a bit longer", it is literally what I suggested.
It is only now, long after the crunch that thinking entire networks would share a single ip (hopefully never running any SIP,bittorrent or something that needs more than one port simultaneously) or the entire network would quickly run out of the 64k ports usable...
So, if Ford and whoever had that second net did give it back when it started to get scarce, all of 33 days is what we would have "won". Good margin for writing up that ipv6 migration plan I guess.
[0] https://www.networkworld.com/article/2228854/microsoft-pays-...
Second reaction (after the "$10/IP" part clicked): oooh, this person is going to have a lot of money soon o.o
But you don't have any contact info in your bio!
(I'm in no position to seriously respond - I'd only want one or two addresses to play with)
Thanks.
https://neverthenetwork.com/notes/lisp/
Full disclosure, the second link is my blog.
I believe Cisco is the only large vendor that's implemented it, but there are Linux and BSD implementations, which should make it easy for any Linux or BSD based NOS to implement it in the future.
Honestly this problem will probably be mostly solved in hardware with larger FIBs/TCAMs
Edit - I should clarify the problem I'm referring to here is fragmentation, not exhaustion.
I could see most others doing it though.
They're pretty low too though
>AFRINIC has no more than one /11 of non-reserved IPv4
Until something forces the transition nothing is going to change.
If they supported IPv6, and gave me a globally routable address that was unfiltered except at my gateway, I'd be happier.
>Our free tunnel broker service enables you to reach the IPv6 Internet by tunneling over existing IPv4 connections from your IPv6 enabled host or router to one of our IPv6 routers.
(It's still obviously less direct, and inferior to your ISP supplying native IPv6, but it may improve your situation.)
There's a list of brokers at https://en.wikipedia.org/wiki/List_of_IPv6_tunnel_brokers
https://6project.org/ looks viable (OpenVPN) and cheap.
It only causes problems for me with absolutely no gain. There isn't a single website I can't reach, and no website that I've found runs any quicker when using IPv6.
But at the same time, if I have v6 on, it causes delays in name resolution and sometimes I just can't connect to a site until I disable v6.
I still have an addressable v4 address, so I can still run a home server.
I don't know how to fix this. I know that v6 is good for the planet, and I know these problems won't get better until more people are using v6, but it's definitely a chicken/egg problem.
That sounds like your ISP does not actually support IPv6, eg. doesn't have the full Internet routing table for v6. I've seen this happen.
DNS v4/v6 resolutions can also hang with glibc because of a well known bug with Happy Eyeballs when ISPs that fuck up outgoing DNS packets (eg. messed up stateful NAT/DPI). "options single-request-reopen" in /etc/resolv.conf is a workaround. See https://bugzilla.redhat.com/show_bug.cgi?id=505105.
I would contact your ISP, or at least publically shame them. This is not how IPv6 Internet should work (source: we provide IPv4/v6 as an ISP and take care to prevent issues like this).
Also, I don't even use my ISPs name servers, I use Cloudflare or Google, so I don't think it's that unless the ISP is somehow munging the packet in transit, which I suppose is possible.
Honestly I think it is all due to issues with the v6 stack in MacOS.
But my point is, I shouldn't have to be a network engineer to make v6 work. I should be able to turn on my computer and just have it work.
That's exactly the problem. You send out two v4 DNS UDP packets one after another (one for A, another for AAAA), both go via your ISPs CGNAT, the CGNAT gets confused, one of the packets gets dropped. I've seen this exact behavior when talking to 8.8.8.8 on Orange in Poland (and they do DS-Lite). It didn't occur with the ISP's DNS, because a) they were also on v6 b) they weren't getting CGNATed.
> But my point is, I shouldn't have to be a network engineer to make v6 work. I should be able to turn on my computer and just have it work.
By disabling IPv6 you're letting shit ISPs get away with this. Your ability to debug this and to figure out it's the ISP's issue should be used to voice your concerns, and not just let this slide.
- Serving different content on IPv4 vs. IPv6, e.g. just showing Apache2's "It Works" page
- Serving some subresources behind a reverse proxy on IPv4 only (and 404ing on IPv6)
- Forgetting IPv6 AAAA Records after a server change
Trying to debug this as a user is annoying and even if I identified the issue before leaving the site, working with sites to get it fixed has been an issue. I quickly ran into the "Works for me" issue, when the administrators (and a majority of their users) ran on IPv4 only networks.
Ultimately I just disabled IPv6 on all my systems because it ends being more trouble than it's worth.
Maybe this is true. But as the other guy said. There is zero benefit in moving to v6 so there isn't any point in taking the time to investigate.
I haven't seen a consumer CPE that both supports v6 and doesn't firewall off incoming v6 connections, and I haven't seen any operating system in years that doesn't enable RFC4941 by default.
Edit: I should point out that I had no idea my machine was using IPv6 until I wondered why I was able to use Gmail and not other sites (such as HN).
With RIRs running out of addresses, that's about to change (well, realistically, maybe in 1-2 years).
As techs, I think it's our responsibility to push this forward and keep the Internet free and decentralized.
I doubt it. Websites that want to be reachable will find a way to be reachable.
> As techs, I think it's our responsibility to push this forward and keep the Internet free and decentralized
I agree, but there is only so much I'm willing to sacrifice for that effort. I've tried to use v6 for at least two weeks on three separate occasions. I do that about once a year. That's the level of sacrifice I'm willing to make for this effort.
My hope is that one year it goes so smoothly I forget to switch back.
IPv6 was always about maintaining the status quo. It doesn't become "better" than IPv4 until CGNAT makes IPv4 worse. (Or if your internal network reaches the scaling limits of RFC1918.)
If everyone is routable it cuts the gordian knot in the "What kind of content should be allowed on our platform?" question by allowing everyone to simply be their own platform. If ipv6 gets adopted fast enough it might just save the 'net from being just a more privacy invasive form of television.
The public commercial platforms offer far more than just a routable IP. You get reach, reliability, resilience, and security (the kind you don't get to build yourself).
Being your own YouTube/FB/Twitter/someChan/etc. platform means almost nobody will ever hear about you, the ones that do can easily wipe you off the internet, coming back is a real hassle, and that your data will leak is basically a forgone conclusion. Being your own Dropbox/GDrive may not need the reach but still relies the other three to provide value. And the list can go on for almost anything you can think of for "being your own platform".
The overwhelmingly vast majority of people have little to no interest in building and maintaining any such platform. It's why so few people actually do it today even when having a routable address. It's inconvenient even for skilled people, let alone regular ones.
I'll wait for a counterargument.
We'd have doused Zuck's dorm room sever in gasoline if we'd known what was to happen.
Let's go back to distributed. Let content proliferate according to novelty and interest gradients. Don't tax it. Don't rent seek.
There are ways to profit without ruining it for everybody else.
I still don't understand how bittorrent (or any decentralized platform) is "your own platform". Most people will always just be part of someone else's platform. Whether it's YouTube, PeerTube, or friendica, it's never their own and IPv6 won't change that. And they explicitly sell themselves as distributed which by definition makes them shared, everybody's, or nobody's. They can never really be your own and that's exactly what their appeal is.
Most people are unable (due to skill, money, or effort constraints) to manage their own platform. And the ones who can don't need to wait for IPv6.
(It's fine to assert things, but make sure you're right first. Asserting things you don't know to be true is disingenuous, and a bad habit.)
Look at the speed with which WhatsApp was adopted (talking about before the FB acquisition), and compare to Mastodon or Diaspora - there is no contest.
If it's getting newspaper coverage, it's probably not all that niche.
If you somehow use them only for yourself so they run effectively as "your own" (assuming you can and want to isolate them) you run into the same issues I mentioned above.
Your comment in brackets applies very much now ;).
Having said that, it's still possible to hear about independent websites, nobody can "easily wipe me off the internet," and I'm pretty sure my data is far more likely to leak from actual YouTube/FB/Twitter/someChan/etc. than it is from a non-monetized, advertising-free Mastodon instance, let alone my static website. But it's also absolutely true that the best way for me to drive traffic to my web site is getting linked from Twitter or Reddit; discovery is one of the big problems for federated, decentralized networks.
Your comment brings a whole new angle to IPv6 I hadn't before considered. Having each packet routable straight to a TCP/UDP port number eliminates the complexities of NAT. Since the {hard,soft}ware that handles NAT wouldn't be needed, perhaps a shift to IPv6 could also give throughput gains.
It does, although barely noticeable. More noticeable is the cost to ISPs for carrier-grade NAT equipment.
I have even found that real world IPv6 addresses are not quite as bad as they look. We have all seen the auto-generated ones and they look awful but you don't actually use those as such. For example you are allocated a /48 prefix: 2001:db8:1234:: in general you might think of the ISP as 2001:db8:: and your site as 2001:db8:1234::. Your first subnet might be say 000a or simply "a" for VLAN 10 because you decide not to allocate IPv6 to your default VLAN 1 and start with your current PC VLAN which is 10.123.10/24. In IPv4 you have 10.123.10.1 as the default gateway (VRRP) with .2 and .3 for the physical routers. Hence your PC VLAN routers get given 2001:db8:1234:a::2 and 3 and ::1 for the VRRP address. You can play games with 1337 addresses using 0-9a-f eg face:b00c sigh.
Not saying that you’re incorrect, but the problem might not be as big as you think.
Home devices are always going to be deployed with an allow outgoing, deny incoming firewall, regardless if they have IPv6 or not. They are identical in terms of security.
https://www.fourmilab.ch/documents/digital-imprimatur/
by John Walker, of Autodesk fame.
The router has a public IP and everything behind it has a local one. That you can do NAT in different contexts and that technically you could have NAT without the firewall functionality doesn't change that this is 99.9% of all NAT applications.
A bit more text about this concept:
https://security.stackexchange.com/questions/176744/why-is-n...
And this is in fact what we see in the real world with IPv6 deployments. Roughly 50% of my country has IPv6, and every single provider provisions it with sensible default firewall rules.
It most certainly does. If you have an insecure device behind a nat, say something with telnet sitting open, a port scanner from the outside won't be able to find it (unless you've gone to great efforts to allow inbound connections without an established outbound connection). This is objectively better than if that device were directly addressable.
> Home devices are always going to be deployed with an allow outgoing, deny incoming firewall, regardless if they have IPv6 or not.
Not always. My last router came with the firewall off and that was just a few years ago. A lot of consumer ISPs don't bother with the firewall because they don't want to field customer service calls about things not working.
This is amazing. How does it work? What stops me going to the devices behind the router?
However, I have yet to see proof of any provider that actually deployed home routers this way.
No, it doesn't. It's a commonly believed myth among people who don't have a clue how IP works, though.
> If you have an insecure device behind a nat, say something with telnet sitting open, a port scanner from the outside won't be able to find it
Why not?
Here's how you do "PAT" on Linux: `iptables -t nat -A POSTROUTING -o wan0 -j MASQUERADE`. Notice how it's limited to outbound connections ("-o wan0")? That means it doesn't apply to inbound connections, and thus doesn't have any effect on the behavior of inbound connections.
If it doesn't have any effect on the behavior of inbound connections, then how could it possibly block inbound connections?
(The typical consumer configuration pairs "PAT" with a firewall, and the firewall does block inbound connections. It's also typical to pair it with RFC1918 addresses, which doesn't block connections but does make it much harder for most people to make the relevant connections in the first place. None of that changes the fact that "PAT" doesn't block connections.)
Obviously you should really use a firewall...
They obviously can't address traffic directly to 192.168.1.0/24 over the Internet as that's a bogon address and the Internet routers will either reject it out of hand, or not know where to send it.
That's not obvious at all. Now, you obviously can't just inject a packet addressed to 192.168.1.1 anywhere on the internet and expect it to turn up on any particular LAN, but that just excludes a subset of the possible attack vectors for unwanted inbound connections.
Your ISP can still send you packets addressed to 192.168.1.1. Thus, obviously anyone compomising your ISP, or some subset of their routers can as well (hello Cisco hardcoded passwords!). Also, it has happened that ISPs failed to isolate customers from one another (think multiple customers on the same VLAN), so your neighbour could send packets addressed to 192.168.1.1 to your router's WAN interface as well. Or potentially malware on their network, if someone were to systematically exploit such a setup.
It isn't even unheard of that ISPs forgot to disable routing protocols on customer-facing interfaces and some CPE managed to advertise their RFC1918 space via RIP to their ISP's access network.
Or, for that matter, an attacker could just hook into your uplink between you and your ISP, if you are a valuable enough target, to gain access to your CPE's WAN interface.
All of those are actually solved security-wise by having a stateful firewall, which will also prevent inbound connections from anywhere else on the internet.
That (for most average consumers) is a vastly reduced attacker set.
Security is not binary, it's a scale.
Except it really doesn't because you haven't?
There are two practically relevant circumstances where the statement "NAT provides security" is made:
1. With regards to real-world home routers (which also come with a stateful firewall), in which case the statement is simply false: Adding or removing NAT makes no difference whatsoever for security. This is also the scenario that then is used to argue against IPv6, because IPv6 supposedly lacks this security, when it just doesn't, because the IPv6 router also comes with a stateful firewall, and adding NAT (or disabling IPv6 because of a "lack of NAT") achieves absolutely nothing security-wise, because there is no problem in the first place.
2. By people who falsely believe that NAT does in fact prevent all inbound connections and for that reason fail to configure the necessary firewall rules on more business-oriented routers, so the belief that "NAT provides security" keeps them from actually securing their network, and that in particular in scenarios where it is much more relevant than for your typical home user.
So, it is technically true that NAT could have security-enhancing effects under artificial circumstances. But under all real circumstances, it either just doesn't, or the belief that it has is what causes the configuration to be less secure than it easily could be, if only people didn't have the completely not-understood belief that "NAT provides security".
This is just arguing semantics. It's not "NAT itself", but a side effect of using it is that it requires deliberate effort to allow inbound connections to get to devices behind the router. This has many of the same effective security benefits as a firewall blocking inbound connections does.
Another way of saying this: the companies that make cheap, crappy routers can do the absolute bare minimum and not end up exposing internal devices to inbound internet traffic. So NAT provides security against the cheap, crappy router manufacturers.
With IPv6, the opposite is true: The router manufacturer has to do deliberate extra effort to block inbound connections, beyond just making the router "work". Will most router manufacturers do this extra effort and include a properly-configured firewall? Probably yes, especially if they don't want to get a terrible reputation for being insecure, which would (hopefully) eventually drive them out of business.
Will absolutely 100% of them always do this properly and never make a mistake? I wouldn't bet on it.
Unless your router has UPnP port forwarding enabled—as most home routers do by default, since popular apps require it—in which case any device can open a hole in the firewall for whatever incoming traffic it wants. In this scenario NAT provides no additional protection beyond what the client device could provide for itself by simply not accepting incoming connections. To get security from a NAT setup you need to disable UPnP and manually configure any required port forwarding, which is at least as much effort as properly configuring an IPv6 firewall.
The right solution IMHO is to have a separate LAN/WLAN/VLAN for the untrusted IoT devices which rejects all inbound connections from the WAN (no UPnP support) as well as all outbound connections to the main LAN. Outbound connections to the WAN for updates or cloud-base control are permitted but logged; inbound connections from the main LAN are also permitted, to control the IoT devices locally. For the main LAN the router should only perform basic filtering for malformed or misrouted packets—ones with an external or multicast destination address or an internal source address, for example. Apart from that, devices on the main LAN are expected to handle their own security. Laptops, smartphones, tablets, and other mobile devices are already required to handle this since they are routinely connected directly to untrusted networks.
A bit incorrect. There are IPv6 protocol changes (ex. ICMP vs ICMPv6) where the newer protocols are more secure. But actually having a private IP behind a NAT gateway is more secure in general, because nobody can directly route to a host behind your NAT, without exploiting reverse NAT traversal. IPv6 will allow easier exploitation of default host configurations due to being able to route to them easier.
This also needs to be balanced against the difficulty of exploiting servers that have been deliberately exposed to the internet, for example cameras or NASs. People often expose those deliberately (via port forwards on v4) so they can access them remotely.
v6 will make it harder to exploit those devices, because it makes it harder to find them in the first place. Most botnets that run on cameras etc spread via random network scanning, so making those devices harder to find makes it harder for botnets to spread. You can consider this akin to vaccination's effect on the R value for a contagious disease: vaccination can eliminate a disease even when it doesn't eliminate 100% of infections. If a botnet can't find enough vulnerable hosts to exploit, it'll die out.
NAT with port forwards makes it far easier to find devices like that, because it reduces the search space. v4 reduces the search space further still, to the point where it's quite feasible to do an exhaustive search.
On balance, I think this makes the larger address space (without NAT) less exploitable.
The way common household NAT works is you have hosts on a private IP space behind a NAT device with an ephemeral internal IP/port table. When an internal device initiates a connection outward the NAT device takes a note of the IP address and port it is connecting to and writes them to the table, along with its own port mapping.
When a packet arrives addressed to the NAT device it checks the table and if it finds a matching entry it rewrites the packet and forwards it back to the original host.
So someone attempting to make a new connection to an internal host is effectively firewalled off by the lack of a mapping table.
Now most people who say "NAT isn't a firewall" are referring to the case where you have for some reason turned off the default firewall rules on the NAT device and have somehow routed a packet with a destination address that is on your internal network. In this case, the NAT will just forward the packet onto your internal host and provide no protection as they say. However, it ignores the difficulty of getting your ISP to route an RFC 1918 address to your NAT device in the first place. The very fact that your internal hosts are on non-routeable addresses is a form of protection provided by NAT.
The lack of a mapping table entry just means that your packet doesn't get translated. It doesn't mean that inside hosts are unreachable.
> Now most people who say "NAT isn't a firewall" are referring to the case where you have for some reason turned off the default firewall rules on the NAT device
Yeah, so: NAT isn't a firewall. The firewall is a firewall. NAT is typically deployed together with a firewall precisely because NAT isn't a firewall.
This is an important distinction, because it means that the security you think you're getting from NAT is actually coming from the firewall, meaning you don't need NAT to get that security.
Note that I'm not ignoring the issue of reaching non-routeable addresses either. Your ISP can route to your LAN range easily, and there are plenty of people who could trick or force your ISP into cooperating. If you want to be secure, you can't rely on "probably I won't receive any evil connections, it'll be fine", you need to actually block them. If you're in a situation where non-routeability is relevant then you were already insecure.
You've also forgotten that NAT doesn't provide you with non-routeable addresses, even if it's typically deployed with them. It works on any address range and it has no impact on the routeability of the range you use. NAT is also not required to use non-routeable addresses (which as mentioned aren't even secure in the first place). So, again, it provides no security.
Were it not for home routers supporting NAT because they need to with IPv4, the same routers would have a basic firewall with that default block rule in place.
NAT itself does have the security benefit of masking more bits of client identity though. If I had a bunch of machines on an ip6 prefix, I would still want their outgoing connections to be NATted, to avoid address-based tracking.
We can envision a better version where each device pulls multiple addresses at a time and rotates through them basically per-topic, but I don't think stacks are really set up to do that. But sure we could get there eventually, at least modulo outdated firmware stuck with said vulnerabilities. On the other hand, if we already need maintained premise routers to manage incoming connections, they can simply NAT outgoing connections and get a perfect probability distribution across IP6+port that fully masks the internal network.
Ultimately I think the distinction between "outgoing" and "incoming" connections is only going to continue increasing, regardless of IP6.
This is such a great analogy.
The Internet has become a dopamine fix. Platforms are generic and inflexible. (Remember when you could change the HTML?) Content is watered down or demonetized for the sake of ad money (Youtube, Tumblr). You can't read the news without getting a video ad shoved down your throat. Commercial video is DRM'd. Browsers (read: Chrome) enables websites to prevent you from copying text or viewing source images. Your every move is tracked to better target ads and sell your profile.
* {
-webkit-user-select: text !important;
user-select: text !important;
}
It is incredible how much more palatable the web becomes with uBlock Origin + uMatrix + Stylus. Not optimistic for the web in the long term, though.
Example: https://www.ghacks.net/2016/05/24/chrome-copy-text-manipulat...
Do you think the adoption of IPv6 would lead ISPs to drop their ban on running servers from non-business accounts?
No, it really doesn't. It makes easier one aspect of developing peer to peer software. Which sure is a good thing, but it's not some panacea. Our regressive software landscape didn't come about because end users simply didn't have easy access to routeable IP addresses. But rather because tinkering with software can be tedious, developing easy to use software takes resources, and the most straightforward way of recouping that investment through surveillance and control.
Right now, you can get a VPS with perfectly routable addresses for $5/mo. And if you're not interested in or able to afford that, you're certainly not going to leave your own machine up 24/7 as a server. In reality, IP/DNS is a namespace that's terrible for user-facing systems - it itself causes centralization by necessitating that singular authoritative servers answer requests for a named object. What we actually need for a non-corporate net is higher level addressing such as content concentric networking (IPFS et al).
(I've gotten some downvotes, and I would be really interested in hearing the actual disagreement. I know we're all biased to think this paradigm of IP4/6 could do everything we want, if only it were used "correctly". But after a few decades of watching things evolve I just don't see how it's sufficient for de-centralization).
Ultimately, technologies are less important than public opinion, politics and commerce in dictating how the net goes.
* Or a single trackable address range, no matter. Yes, ISPs could do differently. Why would they? All the incentives are on the other side.
Sorry, but this is incorrect. No matter how you connect to the internet, someone has to agree to route your traffic. Just having an allocation of "public" address space doesn't mean you are free to do whatever you want. Other people have to actually pick up your traffic.
If you don't have an ASN and a core router on a backbone to announce and carry your traffic, and instead are just using what an ISP gave you, you really have almost no control over whether that address is routable, what protocols you can use with it, etc. They can impose the same limits on IPv6 as IPv4 - and in order to reduce overt abuses of their network resources, they almost certainly will.
Remember: passing packets requires real money. The larger the number of packets, the larger the bandwidth used, the larger the concurrent connections, the more money it costs. Any segment in the network that takes up significantly more traffic than another, will end up costing a disproportionate amount of dollars and maintenance to support. So unless you're paying for all of it, you will have limits. And just like every other resource on the planet, some people will have more resources than others.
IPv6 is identical to IPv4 in terms of what "freedom" you have on the internet.
It is easier to offer services on IPv6 IMHO. If you want to have some boxes at home to SSH into, you need to provide port forwarding after the first.
So for the first system in IPv4 you would have pubip:22 -> inta:22, but then you have to do pubip:23 -> intb:22, pubip:24 -> intc:22, etc.
With IPv6 you can just use the hosts' IPv6 addresses and punch holes for :22 for each individual system as desired: no port tomfoolery needed.
The ISP can decide to impose exactly the same limit on allocated IPv6 as IPv4, and charge you for more hosts. Your freedom hasn't changed, only your billing has.
So from where I'm standing IPv6 is not identical to IPv4.
Given how sht the security on IoTs is I'm not convinced giving everything a routable IP is a good idea frankly. At least not until the IoT players up their game significantly
Also NAT is not a firewall, but that’s a story for another day.
I don't think that even given widespread IPv6 adoption, we'll ever go back to a model where residential or mobile internet connections will allow for public reachability by default.
Of course, NATs and firewalls are not the same thing (you just effectively happen to get the latter when deploying the former). But I firmly believe that the bulk of technologies that give us dynamic endpoint lookup and coordinated firewall traversal will outlive IPv4 and NAT.
As an anecdotal example, I used to have a mobile data plan that assigned a public IPv4 address to my phone, including inbound TCP/UDP reachability! That's neither good for battery life, nor for data consumption (on a metered plan). By contrast, my current one puts me behind a carrier grade NAT, but I have no problems whatsoever making peer to peer VoIP calls to friends behind the same type of NAT.
a) for one as a response against CGN, thankfully my ISP isn't using one right now but I have a hunch they're going to start becoming a lot more common in the future. and b) as a hacker I'm interested to finally set it up and play around with it.
Also IMO even if it doesn't bring any improvements to the general consumer given all the pressure to start switching to IPv6 it is a good thing to be interested about it, pressuring more ISPs to start supporting it.
the isp could also provide dynamic dns as part of their package for users who do want to access their devices at home. why remember a 4-octet ip when you can get your own subdomain from your internet provider?
So as long as I connect to the EC2 instance over IPv6, I get a free static IP address on my server.
Maybe you could elaborate on why you assume these things are bad?
And before now, there were still some unused addresses available. We've just begun the phase where we have to scrounge for loose change in the couch cushions. Previously there was money in the wallet. (Only a little, but that's what you use first.)
My guess is scrounging will initially be easy. Then it will get gradually harder, until eventually it becomes easier to just use IPv6, and then people will switch over.
This is the chicken-and-egg problem that all new networks are facing with regard to IPv6 adoption. In order to have a usable network, you have to support IPv4 to all endpoints. But once you have v4 at all endpoints, the incentive to run v6 is greatly diminished.
As always, v6 needs a "killer app" that Grandma wants to use that is unavailable over the v4 internet, and then network administrators could use the actual demand from their customers as a justification for moving to v6. Unfortunately, at the moment, the list of v4-only must-have apps is still greater than the list of v6-only must-have apps.
Amusingly that's how mobile/smartphones are supposedly run: the devices get IPv6-only, and if they need to hit an IPv4-only address they are CGNATed.
* https://www.internetsociety.org/resources/deploy360/2014/cas...
* https://blogs.akamai.com/2016/06/preparing-for-ipv6-only-mob...
They certainly could be using CGNAT, but that seems like a weird way to do it.
How are you able to tell with IPv4? You cannot run ifconfig on an iPhone, so how are you determining that?
Maybe we've done too early (it was about five years ago maybe, I don't really remember exactly) and now tooling is better, idk
Unfortunately Virgin Media (my ISP) are still dragging their heels but have decided to go with DS-Lite.
(And apparently the police are not big fans either, as it makes it more difficult to track down miscreants).
From a consumer standpoint the problems I've run into and heard about are:
1. Can't use port-forwarding anymore since you can't configure the ISPs router doing the NAT
2. A bad neighbor sharing your IP can get you IP banned on sites that still think IP address is a good way to block/throttle bad players
3. Connections can be unstable if there's a lot of connections going on, so prime-time can often run into issues.
Not at all, it's a stupid idea. You are trying to nail down an identity without authentication, that can not work. If you use credentials with sufficiently high entropy, which you should do anyway, you don't have a problem that this could be the solution to.
In Finland 2 out of 3 mobile operators give you IPv6 by default (and mobile data usage is very high).
Many large cable ISPs in the USA have been running IPv6 internally for years now. They likely have some of the largest deployments if you account for all their IP managed gear.
Of course, these are the same ISPs that already provide a dual-stack gateway to their customers.
CableOne/Sparklight says hi, because they have zero intention on deploying v6 for the foreseeable future.
At least in Poland, you must provide law enforcement with information about your subscriber for any given 5-tuple at a given time (timestamp, {src,dest}{ip,port} and protocol). If you're CGNATing everyone, you have to either:
- log all outgoing connections (which is a GDPR hazard)
- design your CGNAT to use static outgoing ports for a given customer (but then you're running out of ports pretty fast, if you're doing anything close to >=500 subscribers)
With IPv6, you can just immediately tell who the subscriber is based on the IP address, and as such don't have to log anything.
Most of the stuff regular people care about performance for is on CDNs that support IPv6 (or is YouTube, Netflix etc)
https://www.aussiebroadband.com.au/help-centre/nbn/tech-supp...
The adoption rate has been really slow.
Honestly stupid that USDoD controls at least 13/256 of all IPv4 addresses.
It seems some entities, e.g. IBM and MIT, have returned (sold?) their /8s to their RIRs though.
Good on GEC, IBM, HP or Xerox for having relinquished their(s).
I figured IBM would eventually sell it off and I wasn't looking forward to the day I'd have to reIP all those systems. Glad I missed that party.
--Edit I just did a whois on some the IPs that I remember. Looks like IBM still has big chunks of the 9.0.0.0/8. Likely only sold off what they hadn't already used. Honestly I'm surprised they sold off any of them. With their cloud ambitions I'd think they want to keep them for use there.
When pressure is zero and effort is high, things will go unchanged. I'm sure once pressure exists then some movement will occur. It seems most of the industry is doing everything they can to put off incurring pressure, though.
Ipv6 really only serves to shed load off CGNAT since we rely on the continued use of v4 addresses since v6 is not interoperable with v4.
But why should Reddit support v6? For the greater good of v4 by reducing pressure of CGNAT for dual homed users. But wait, who are the dual homed users you may ask? Mobile users. And it will only be mobile users since autoconfiguring residental networks to dual home is not going to happen. But Mobile carriers have full control of addressing and TCP/IP configuration of handsets, and so they can easily deploy usable v6.
So the smaller sites shouldn't bother with v6 because they're not an essential part of the Internet with large traffic. But a site like Reddit can reduce enormous pressure for mobile carriers to deliver use of the Internet.
https://news.ycombinator.com/item?id=2174992 9y
https://news.ycombinator.com/item?id=4480532 7y
Looking forward to the next time we run out of IPv4 addresses.
First link: Last ICANN (global) RIR-reserved block assigned allocated to a RIR. End of the line for blocks that were globally reserved for, but yet unused by RIRs.
Second link: RIPE (a RIR) has one month until it starts distributing its last /8 block (185.0.0.0/8) to LIRs.
Now: 185.0.0.0/8 and small bits and bobs that RIPE still had for LIRs (ISPs) is gone. No more IPv4 for European/ME ISPs from RIPE, only gray market available.
The previous posts were the writing on the wall. Now we're actually fucked.
I checked, and IPv4 address price is somewhere between $20 and $30[0]. It's not so bad given it's a one-time buy - and using cloud services de facto creates a situation where the buying is in bulk.
The real shortage will start be when prices reach $170 I guess? Should take a few years...
Not only will no shortage occur, but the upgrades will be performed for the least cost possible. This is the kind of resource allocation problem that markets solve optimally.
There won't be a situation where a business will not put up a site due to lack of IPs, they'll switch if/when they have to.
Are there any guides for how to properly secure a home network so that I can re-enable IPv6 with a clear conscience?
They don't know what you're going to use it for and in real networks, the sensible home default of "allow outcoming deny incoming" doesn't usually make much sense. You're probably going to have dedicated firewall devices somewhere else in your network.
You can always enable v6, then see if you can reach internal machines from a machine on the internet (like a VPS or over a cell connection)
For most home IPv6 networks, blocking all incoming traffic from the egress port will achieve the same level of security as a NAT'd IPv4. Different router/fw manufacturers would need their own guides on how to do that, but IMO any sane consumer product should be configured like that by default.
Here's a guide for OpenBSD, for instance. Note how it includes "block all" which means it blocks everything not specifically allowed. https://www.openbsd.org/faq/pf/example1.html#pf
ip6tables -P FORWARD REJECT
ip6tables -F FORWARD
ip6tables -A FORWARD -o wan -s 2a42:.../64 -j ACCEPT
ip6tables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
This makes sense, considering ISPs might not want to deal with a ton of pwned devices that are now part of botnets.
ip6tables -A FORWARD -p icmpv6 -j ACCEPTIf you have a Asus/Dlink/whatever there's nothing special to be done.
Who cares about cookies, 1st party or 3rd party, when you have a unique ~60 bit per customer identifier?
My ISP gives un-natted IPv4, but I get a different one each time I reboot the modem, which I do every now and then.
1) ping6 ff02::1%eth0
2) Advertise the device and it's services (such as ssh) via avahi.
3) Set a static address such as fe80::1 (link local), fd00::1 (ULA), or 2001::1 (your prefix).
What you're probably going to see is increasing cost to keep a dedicated public IPv4 address. If you don't, you will probably either have to have IPv6 or NAT.
Residential will probably lose public IPv4 addresses faster than for hosting services.
If I were to remove cloudflare, more than 30% of users can connect to the site via IPv6. Problem is that other 70% will consider the site dead and move on.
Most systems (maybe 70% today) couldn't reach it, it's harder to estimate how many _people_ because people may have many options to access the Network and some are more likely than others to be IPv6 enabled.
It also varies geographically, in some places (e.g. Germany) it may be about half of people who have IPv6 access, in say Australia it might be more like a quarter and so 75% could not reach that site.
As we see above in this HN thread some users intentionally disable IPv6.
But I can't send anything to such a user directly if they don't support IPv6 and I don't have an IPv4 address.
Perhaps we need some community-run webservice with an explanatory page saying "Website [something.com] requires IPv6, here's lots of documentation on how to try and fix this" and everyone could point their domain name IPv4 address to that webservice, and the IPv6 address to the real server.
For hobby projects hosted on a Raspberry Pi in someone’s bedroom, I can imagine a static IPv4 being prohibitively expensive, but that’s about it.
Eventually maybe a premium for an ipv4 static IP on some cloud provider but that’s about it. The big players have plenty of CIDR.
They already have high-performance domain-aware routers, so you can still basically run a million websites via a single ipv4 address.
...if not residential ISPs then certainly mobile-phone/wireless providers.
Home providers will start tunnelling ipv4 traffic over v6 (this is already the case here, termed "Dual-Stack Lite"), computers will start start doing 4->6 translation locally according to instructions given over Route Advertisements, hosters will start providing ipv4 load balancers to make their VMs v4-reachable, etc.
It looks to me like we are heading to world where ipv4 will work forever, but be turned into ipv6 at the first possible opportunity.
One way to accelerate their adoption, though, could be throttling IPv4 transfers: have, say, youtube or Netflix faster at an ISP that enabled it. Or less lag for online games.
This is not 1995 when you needed to connect to other users of the Internet to get stuff done.
Fundamentally, TCP won't allow more than 64K connections from one IP to a single port on another IP. That's a hard limit on the number of users behind a NAT of any kind who can simultaneously connect to a given service on a fixed port. Right now my ISP's resolvers are returning exactly two IPs for google.com. If it were infected with CGNAT, at most 128K of my ISP's customers could use Google at the same time. The real number is much smaller as fetching a web page typically opens lots of connections.
No, I stand by it: CGNAT is dead tech that only has a short window of feasibility. It breaks way more than a migration to IPv6 would, and it's a short-sighted solution for the previous century.
I have all of that with CGNAT.
>Fundamentally, TCP won't allow more than 64K connections from one IP to a single port on another IP. That's a hard limit on the number of users behind a NAT of any kind who can simultaneously connect to a given service on a fixed port. Right now my ISP's resolvers are returning exactly two IPs for google.com. If it were infected with CGNAT, at most 128K of my ISP's customers could use Google at the same time. The real number is much smaller as fetching a web page typically opens lots of connections.
First, Google has tons of IP addresses, not only two. Second, ISPs with CGNAT servers don't have only one for all customers.
With all these elastic search instances running open to the public I have the feeling that with IPv6 this will get worse as NAT no longer protects you.
I'd wager most home networks are protected only by the fact that they use NAT. ISPs are getting better about shipping routers with firewalls on by default, but it's still not there.
Their requirement is probably for their addresses to be globally unique.
Historical addressing plans being what they are, they probably have sparse assignments across all blocks. Re-numbering existing systems is a non-trivial exercise with high costs. There is no benefit to them to doing this, and we have known this exhaustion is coming for literally decades now.
Just because they're not in use on the Internet, doesn't mean they're not in use.
> With all these elastic search instances running open to the public I have the feeling that with IPv6 this will get worse as NAT no longer protects you.
Stateful firewalls protect you. NAT does not.
(Have you ever seen even an old IPv4-only home router that didn't include a firewall? I haven't.)
On a real firewall, generally you don't reroute a port to a different IP, you just pass or fail the packet.
Other large holders include Apple, Ford, Prudential Insurance and the USPS.
More easy answers to similar questions here: https://en.wikipedia.org/wiki/List_of_assigned_/8_IPv4_addre...
You're not the first person to ask this, and the answer is: not nearly enough.
Demand for IPv4 is orders of magnitude larger than the current address space. There is no level of freeing up addresses that can make this problem go away. At most we're buying us a few months until we run out again.
But, now that it's happened … it shoots to the top story.
For anyone interested, the blog post from RIPE that I submitted is still up, here: https://www.ripe.net/publications/news/about-ripe-ncc-and-ri...
So why are IPv4 addresses so valuable? Mostly because IPv6 is overly-complicated and a pain to work with. We should have first added a new range where 5 of the 8 hextets were 0000. And found a simple way to write it without ::
Why wasn't that done?
The road to hell is paved with good intentions so I guess I will see you all in hell.
For client use, carrier-grade NATs allows to have 1000 IPs per customer, giving 6 million addresses.
For server use, TLS SNI allows to have one IP per datacenter, which are estimated to be around 10 million in the world.
Non-TLS inbound usage is probably relatively rare, so overall around 100 million addresses should be fundamentally enough even accounting growth.
Of course there's a lot of inefficiencies, but the fundamentals seem to say that the IPv4 address space is enough.
TLS SNI is awesome, but no plausible implementation is going to let you put an entire datacenter worth of addresses behind a single address. That's not going to happen.
IPv4's time is soon to be past. Google is nearly hitting 30% IPv6 usage already, and it's still growing. This is the way forward, not junk tech like CGN or millions of hosts on a single TLS SNI address.