IPV6 in IPV4 (6in4)


I think this must be explained here in detail, so I would appreciate if you could point me to the correct thread..

I have Comcast/Residential, so I get 1x dynamic IPV4 address and I also seem to be getting some IPV6 address on my openwrt router with prefix of 2601:///

I understand from my reading my dynamically allocated IPV4 address of say can correspond to
2002:6363:6363::/48 with the 6in4 mechanism which allows for "65,536 LAN segments"

So my question is, is it possible for me to say have a personal domainname
and MAP it to one of the IPV6 address under that 2002:6363:6363::/48 which I can say host in my local LAN and have some openwrt configuration to relay that IPV6 to the IPV6 of say some R-Pi server inside my network

Is it technically possible for me to host such 65K+ webservers each with dedicated IPv6 address which can map to 65K+ domains with a single IPv4 dynamic address ?

Just trying to think outside the BOX :slight_smile: or I have got it all wrong :roll_eyes:

Why do you think that you have 6in4 tunneling instead of the native IPv6?

Probably you have quite normal IPv6 addressing.

And yes, you likely have dynamically allocated more IPv6 addresses (at least 2^64, or likely 2^16 times that = 2^80 IPv6 addresses if your have a /48 prefix) than the whole IPv4 address space with 2^32 addresses.

But your addresses are not found via domain names with DNS, so simply trying to set them as www.zyxxy.com would not work. But if you use a dynamic DDNS service, it would well be possible to allocated servers there with foundable names like myserver.mydomain.xxx

The IPv6 address space size is mind-boggling. You really have at minimum (the old IPv4 address space)^2 of IPv6 addresses, as that is /64 (and consumers get typically allocated /56 or /48).


It would clear things out to see the configuration:

Please copy the output of the following commands and post it here using the "Preformatted text </> " button:
Remember to redact passwords, MAC addresses and any public IP addresses you may have

ubus call system board; \
uci export network; uci export wireless; \
uci export dhcp; uci export firewall; \
head -n -0 /etc/firewall.user; \
ip -4 addr ; ip -4 ro li tab all ; ip -4 ru; ip -6 addr ; ip -6 ro li tab all ; ip -6 ru;

Yes I plan to use a DDNS. I dont want to pay Comcast for a crappy service and add on paying more for a block of static IPV4 addresses.

I still fiddling with the configuration of a GL-Inet B1300 router (switching) after I deploy that I want to bring up my internal services up to the internet and was thinking of using IPV6 based web server/ices with a single IPV4 address.

So I understand that this is possible !


What? Why?
You are mixing two different things.

If you have native IPv6, there is no reason to think about "using IPv4 for IPv6". All tunneling causes performance loss due to package encapsulation, and naturally you would also need to use some 6in4 tunneling service company for the other endpoint.


IPv4 and IPv6 work independently unless you rely on the IPv4/IPv6 transition.