All IPv4 addresses can already be represented in the IPv6 address space, by the same method you describe here.
As for “backwards compatible with IPv4”, I’m afraid that’s not possible for the same reason IPv6 isn’t getting major traction. Right now, we literally CANNOT upgrade our entire networking infrastructure. What you’re proposing requires updating every switch and middlebox to support routing using additional bytes, which is physically impossible. The biggest problem would be middleboxes, which includes NAT router, firewalls, etc. For context: most middleboxes drop anything that is not IPv4/TCP or IPv4/UDP. This is why QUIC is encapsulated inside a UDP header (and funny enough, these vendors STILL didn’t learn, trying to match a “QUIC header” despite Google themselves saying there is no fixed QUIC header), and RoCEv2 using a header that looks like UDP. There is absolutely no way a new L3 protocol that is not IPv4 (and in some cases, IPv6) can be supported by these boxes.
The only time we successfully replaced the L3 protocol was with the adaption of IPv4. In which networks were much smaller, and networking research was under the US DoD. The DoD basically gave an ultimatum that “if you don’t switch to IP by this date we will cut your funding”. That won’t fly now that the Internet is managed by a cluster of ISPs.
Also: IPv6 is stupid simple. It’s basically IPv4, with everything not commonly used stripped out (and added back with “optional headers”, and a much larger address field. Since the address field is much larger, it is recommended to write them in hexadecimal, which looks more scary than IPv4.
Just fyi IPv8 was written by LLM with full on hallucinated citations and references. It isn’t being taken seriously by anyone.
It didn’t even make sense. It relies on DNS for nat and the like. Deranged networking plans from the non-mind of an LLM.
I recommend taking the time to learn IPv6 properly. It’s actually quite elegant and brings back the peer to peer, endpoint to endpoint connection ability of the old internet.
True. But pinging IPs directly should only be done as a debug step when dns / mdns does not work. Aka extremely rarely.This all being said mdns is extremely reliable on lan. It’s literally just multicast dns on lan.
On my personal home network I have never had mdns fail in 5-ish years. FQDNs yah. DNS can break. But mdns has been solid.
I wouldn’t even say it was a good idea. Like the end to end NAT free internet is the ideal. IPv6 was built for that.
Even if IPv8 was not slop it would reenforce the idea of nat and hierarchy.
IPv6 allows for a democratized internet where anyone can choose to self host. And anyone can connect to anyone who is self hosting.
Because of this it’s a bit more complicated. But ideology it much better than IPv8. It brings us back what made the internet great in the 90s and 2000s, but at scale.
I really like how ipv6 works; the downside is it’s way more complicated for humans to understand. But then again all of networking gets complicated fast. I still don’t really get what a CGNAT is.
How is IPv6 harder to understand? It’s just IPv4 with all the uncommon stuff stripped out and put into optional headers (which IPv4 also has), and a much longer address now written in hex.
CGNAT is just a fancy term for NAT done by a carrier. They get a special private IP address range for doing so, but fundamentally it’s still NAT.
Now IP multicast, THAT is complicated for humans to understand. Especially the whole subscriber logic.
I literally just got the notifiation from Verizon today that IPV6 was now supported by their network… Ubiquiti asked me if I wanted to enable it, my response is basically not until I understand it…
Then again, it took me 20 years to really understand IPv4, so it’s likely I’m going to be decaying before I get v6. ;-)
Note while you have cosmetic similarities to ipv4 addresses, the actual challenging part of that is the packet format and various translations.
We actually have a number of existing schemes for ipv4 mapping onto larger address space and the attendant NAT requirements. The presentation of addresses in an ipv4 looking way is the least of the challenges.
So don’t take IPv8 seriously, it is slop and even in theory it wouldn’t add anything new except a different cosmetic look to raw addresses and shortening the address space for no good reason.
it would obviously involve code updates for compability, and I don’t pretend to know how it would work long term, but it makes the most sense… By prepending the zeros, you expand the number of networks dramatically.
I would guess that no matter what, everything gets an upgrade… But I think this might make it more seamless.
Basically people see an address like fdec:46f7:9b7f:1::3:20 and run screaming away about the complexity, seeing the address as a comprehensive indication of complexity, even though the real challenges lie underneath.
The whole ‘traditional ipv4 just has 0.0.0.0’ stuck in front of it is essentially exactly the same idea as, say 64:ff9b::142.251.152.119. Now there’s also the likes of ffff::142.251.152.119 but that’s just so software can pretend to speak IPv6 when the OS is really doing only IPv4. So they needed another prefix to indicate the network doing the v6 to v4 translation instead of the OS.
Anyway, the thing is that while it cosmetically looks more similar, it’s not really solving the fundamental compatibility situation. It just “looks nicer” because it sticks to dotted decimals. However in practice, would fdec:46f7:9b7f:1::3:20 really be somehow less usable than, say, 120.30.204.78.167.144.120.209? The simple reality is that the 4 octet decimal pushed human usability enough as it was, and going to sufficient octets just brings it out of mere mortal reach. If you did want to say have more friendly local network addresses (the vast vast majority of human memorized IP addresses), then technically you could have fd::1, fd::2, fd::3, and those would all work and be super easy to remember (the ULA RFC says you are supposed to toss in 40 bits of random for good reason, but if you were using 10.0.0.1 style addresses, you would be no worse off with fd::1, fd::2, etc). You can even trivially have them live alongside ‘real’ global IP addresses, but ignore them whenever you want to just hand type a local IP address. You can even have something like a hex DNS. fd::f00d, fd::beef, fd::d00d, and so many more for your pleasure.
There’s more features in IPv6 but you can ignore them since they are mostly for the machines to wrangle (the fe80:: addresses for example).
nitpick, but I would say “an RFC”, as there’s been a number of these over the years
you’ve gotten a couple responses so far, but I think the central issue is that “complexity” isn’t the problem with IPv6 (and one could certainly argue that IPv6 is actually simpler)–the problem is compatibility. This article lays out the issue very well, and also links to this article (which is a more specific look at the IPv8 proposal you refer to). Both point to the same conclusion, which is that fundamentally–on first principles–existing hardware does not know how to handle the upgrade, which will require some sort of dual-stacking, which is the issue IPv6 currently has. (Not its technical merit.)
TLD’s aren’t the limitation… Public IPs are… If it wasn’t for Cloudflared, I couldn’t run half the shit I run.
in an ideal world, ipv6 would solve that problem…
😔
I saw the rfc for IPV8 recently… It makes so much more sense than ipv6…and is backward compatible with ipv4…
Basically they’re proposing prefacing 4 more octets into an IP address, so 172.16.5.1 would become 0.0.0.0.172.16.5.1
Any existing IPs would just assume the 0.0.0.0 in front of them…
Again…solves the problem on much the same way.
Networking researcher here chiming in.
All IPv4 addresses can already be represented in the IPv6 address space, by the same method you describe here.
As for “backwards compatible with IPv4”, I’m afraid that’s not possible for the same reason IPv6 isn’t getting major traction. Right now, we literally CANNOT upgrade our entire networking infrastructure. What you’re proposing requires updating every switch and middlebox to support routing using additional bytes, which is physically impossible. The biggest problem would be middleboxes, which includes NAT router, firewalls, etc. For context: most middleboxes drop anything that is not IPv4/TCP or IPv4/UDP. This is why QUIC is encapsulated inside a UDP header (and funny enough, these vendors STILL didn’t learn, trying to match a “QUIC header” despite Google themselves saying there is no fixed QUIC header), and RoCEv2 using a header that looks like UDP. There is absolutely no way a new L3 protocol that is not IPv4 (and in some cases, IPv6) can be supported by these boxes.
The only time we successfully replaced the L3 protocol was with the adaption of IPv4. In which networks were much smaller, and networking research was under the US DoD. The DoD basically gave an ultimatum that “if you don’t switch to IP by this date we will cut your funding”. That won’t fly now that the Internet is managed by a cluster of ISPs.
Also: IPv6 is stupid simple. It’s basically IPv4, with everything not commonly used stripped out (and added back with “optional headers”, and a much larger address field. Since the address field is much larger, it is recommended to write them in hexadecimal, which looks more scary than IPv4.
Just fyi IPv8 was written by LLM with full on hallucinated citations and references. It isn’t being taken seriously by anyone.
It didn’t even make sense. It relies on DNS for nat and the like. Deranged networking plans from the non-mind of an LLM.
I recommend taking the time to learn IPv6 properly. It’s actually quite elegant and brings back the peer to peer, endpoint to endpoint connection ability of the old internet.
I’m okay with IPv6, if I can get a hexadecimal keypad. I know, DNS solves it to a degree, but just pumping in link-local can be a keyboard dance.
Unfortunately, my ISP doesn’t yet offer IPv6 due to PPPoE to authenticate and authorize subscribers.
Humans shouldn’t really be typing in IPs. Why not just use localhost for localhost and dns / mdns for lan machines? It’s such a nicer experience.
mdns works with link-local in the case of a private non connected lan.
Dns doesn’t always work, and seeing if you can connect via IP is often a troubleshooting step
True. But pinging IPs directly should only be done as a debug step when dns / mdns does not work. Aka extremely rarely.This all being said mdns is extremely reliable on lan. It’s literally just multicast dns on lan.
On my personal home network I have never had mdns fail in 5-ish years. FQDNs yah. DNS can break. But mdns has been solid.
Oi…well that sucks ass. A good idea, badly conceptualized I guess.
I wouldn’t even say it was a good idea. Like the end to end NAT free internet is the ideal. IPv6 was built for that.
Even if IPv8 was not slop it would reenforce the idea of nat and hierarchy.
IPv6 allows for a democratized internet where anyone can choose to self host. And anyone can connect to anyone who is self hosting.
Because of this it’s a bit more complicated. But ideology it much better than IPv8. It brings us back what made the internet great in the 90s and 2000s, but at scale.
I really like how ipv6 works; the downside is it’s way more complicated for humans to understand. But then again all of networking gets complicated fast. I still don’t really get what a CGNAT is.
How is IPv6 harder to understand? It’s just IPv4 with all the uncommon stuff stripped out and put into optional headers (which IPv4 also has), and a much longer address now written in hex.
CGNAT is just a fancy term for NAT done by a carrier. They get a special private IP address range for doing so, but fundamentally it’s still NAT.
Now IP multicast, THAT is complicated for humans to understand. Especially the whole subscriber logic.
Probably true…but I just don’t see it taking off…
IPv6 is now peaking over 50% of all internet traffic globally and trending up. IPv4 is today the minority of internet traffic.
In some countries like France IPv6 over 85% of all internet traffic. In Germany over 75%. USA 57% of all traffic. India 76% of all traffic.
Not a fan of Google but they keep statistics on adoption.
https://www.google.com/intl/en/ipv6/statistics.html
I literally just got the notifiation from Verizon today that IPV6 was now supported by their network… Ubiquiti asked me if I wanted to enable it, my response is basically not until I understand it…
Then again, it took me 20 years to really understand IPv4, so it’s likely I’m going to be decaying before I get v6. ;-)
Note while you have cosmetic similarities to ipv4 addresses, the actual challenging part of that is the packet format and various translations.
We actually have a number of existing schemes for ipv4 mapping onto larger address space and the attendant NAT requirements. The presentation of addresses in an ipv4 looking way is the least of the challenges.
So don’t take IPv8 seriously, it is slop and even in theory it wouldn’t add anything new except a different cosmetic look to raw addresses and shortening the address space for no good reason.
That’s not how header backward compatibility works. IPv4 routers would discard the packet, not prepend zeroes.
it would obviously involve code updates for compability, and I don’t pretend to know how it would work long term, but it makes the most sense… By prepending the zeros, you expand the number of networks dramatically.
I would guess that no matter what, everything gets an upgrade… But I think this might make it more seamless.
Everyone seems to think that IPv6 is a complicated solution to a simple problem, it’s not. If you want to learn more, I managed to track down an article I read a while ago from one of the original IPng engineers. https://github.com/becarpenter/book6/blob/main/01. Introduction and Foreword/Why IPv6 is so complicated.md
we both thought of the same article haha
Basically people see an address like fdec:46f7:9b7f:1::3:20 and run screaming away about the complexity, seeing the address as a comprehensive indication of complexity, even though the real challenges lie underneath.
The whole ‘traditional ipv4 just has 0.0.0.0’ stuck in front of it is essentially exactly the same idea as, say 64:ff9b::142.251.152.119. Now there’s also the likes of ffff::142.251.152.119 but that’s just so software can pretend to speak IPv6 when the OS is really doing only IPv4. So they needed another prefix to indicate the network doing the v6 to v4 translation instead of the OS.
Anyway, the thing is that while it cosmetically looks more similar, it’s not really solving the fundamental compatibility situation. It just “looks nicer” because it sticks to dotted decimals. However in practice, would fdec:46f7:9b7f:1::3:20 really be somehow less usable than, say, 120.30.204.78.167.144.120.209? The simple reality is that the 4 octet decimal pushed human usability enough as it was, and going to sufficient octets just brings it out of mere mortal reach. If you did want to say have more friendly local network addresses (the vast vast majority of human memorized IP addresses), then technically you could have fd::1, fd::2, fd::3, and those would all work and be super easy to remember (the ULA RFC says you are supposed to toss in 40 bits of random for good reason, but if you were using 10.0.0.1 style addresses, you would be no worse off with fd::1, fd::2, etc). You can even trivially have them live alongside ‘real’ global IP addresses, but ignore them whenever you want to just hand type a local IP address. You can even have something like a hex DNS. fd::f00d, fd::beef, fd::d00d, and so many more for your pleasure.
There’s more features in IPv6 but you can ignore them since they are mostly for the machines to wrangle (the fe80:: addresses for example).
nitpick, but I would say “an RFC”, as there’s been a number of these over the years
you’ve gotten a couple responses so far, but I think the central issue is that “complexity” isn’t the problem with IPv6 (and one could certainly argue that IPv6 is actually simpler)–the problem is compatibility. This article lays out the issue very well, and also links to this article (which is a more specific look at the IPv8 proposal you refer to). Both point to the same conclusion, which is that fundamentally–on first principles–existing hardware does not know how to handle the upgrade, which will require some sort of dual-stacking, which is the issue IPv6 currently has. (Not its technical merit.)
True, good point. AN RFC…
To be fair, I never got IPV6… was too confusing. I’ve always been able to rattle off IPv4 addresses in my sleep. IPV6 just wasn’t as natural.
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I have a whole /56 of public IP addresses 😉