It seems interesting to think about building and testing OpenWrt without any IPv4 support. Has anybody tried this already?
I read that Linux cannot be built without IPv4 today. Likely quite a few modules could be dropped and possibly IPv4 support could be disabled.
The first problem I imagine I would run into, how to access the device after installing OpenWrt? Usually I connect to 192.168.1.1. For IPv6 one could possibly derive a link-local address from the MAC address that's written on the device. Would that seem the easiest entry point or might there be an easier mechanism?
That is still the case, and with that your plan goes out of the window. You obviously don't need to enable IPv4 in your interface configuration, but you can't omit it.
Yes, assuming ipv6 ever makes it to being "The Internet Protocol", I agree, now is maybe the time to start taking things seriously!
Ultimately, maybe after much upstream re-factoring, OpenWrt could split out ipv4 support into optional kmods, like many other kernel functions already are.
Currently though, the great majority of web sites are still ipv4 only so there is still a long way to go. Maybe something entirely new will take us all by storm making both ipv4 and ipv6 obsolete....
Yes, out of necessity for a particular use case.
The mesh11sd package will by default autonomously configure meshnodes (routers) every reboot and dynamically at run time. If a node finds itself with an upstream Internet connection it will become a layer 3 router. For ipv4 support it creates a subnet, the address of which is based on the hash of its mac address.
Long story short - if the router does not have an ipv4 address, or you don't know it, how do you SSH into it?
This is relatively easy and can be used with any router, not just mesh. See: Open a Terminal Session
However if you want a Luci-web-ui login, then it is more complicated because most, if not all, browsers will block link-local addresses.
To get round this you will have to find the ipv6 ULA gateway address and that is another story.
Is Ipv6 adoption on a typical S curve, or is it slow linear or even stalled?
If the former it could happen very quickly, if the latter it is ripe for that "something new" to come along and totally disrupt our little world
But then we have China's push for ipv6 dominance by 2030.
Alternatively SDN (Software Defined Networking) and NDN (Named Data Networking) are hiding in the wings....
But what would that address resolve to? And how could it resolve? Does OpenWrt advertise DNS resolving out of the box to its link-local address or might it be necessary to introduce something for that? Maybe Avahi could help here?
All my ISPs have been supporting IPv6 for the past 22 years. With just IPv6, I could use https://nat64.xyz/ for most IPv4 needs. So even today I could look into moving my home network to IPv6-only
Home networks runs IPv6-only for most VLANs.
Therefore the initiative to start configuring OpenWrt for an IPv6 first experience would be great and I would support this and will help.
As there is no RFC1918 address, I would assume IPv6 needs to be setup the the default LAN is anounced correctly and documentation need to take care about the discoverablity.
Futhermore RFC7217 behavior for WAN and LAN need to be correctly configured to address RFC7721 recommendations.
@anon63541380 Europe and here especially France and Germany are leading with up to 85% IPv6 adoption.
New ISPs don't have native IPv4, as they cannot afford and get legacy ressources.
I just set up an IPv6-only network on a dedicated router and it indeed works as @anon63541380 indicated. I put jool on my main router so that from the perspective of this dedicated router, all traffic can be IPv6-only.
I'm not familiar with RFC7217 or RFC7721. I'll try to go through them but if you have some pointers regarding what I should look into, I'd appreciate that!
That part is 'relatively easy', as all the necessary parts already exist - what is missing, is making it (this mostly boils down to the IPv6-first transition mechanisms for IPv4 support) user friendly in the sense of integrating it properly into netifd and luci (and not having to write custom start scripts, etc.). Even though it's 'all out there' already, don't underestimate the effort required for the last mile.
While not a 1:1 equivalent, ULA prefixes go a long way into this direction (but yes, DNS).
Looking at nlbwmon for the last 3 months, ~75% of the accounted traffic is already IPv6 for me. Given that I am with a cgNAT + semi-static IPv6 /56 ISP, IPv6 is an important aspect for me (albeit less so the IPv6-only desire), because it's the only way to reach my VPN endpoint.
