The problem with ipc6 is that transparent v4 support My ISP gives me an ipv6 range of 2001:abc:ab23:: (well something very similar) routed down the pppoe tunne

The problem with ipc6 is that transparent v4 support My ISP gives me an ipv6 range of 2001:abc:ab23:: (well something very similar) routed down the pppoe tunnel (which autoestablishes ipv6 with a /128 IP, just like my ipv4 establishes with a /32) I thus have my ipv6 vlan 2301 as 2001:abc:ab23:2301::/64 The router is at 2001:abc:ab23:2301:: (which is 2001:abc:ab23:2301:0:0:0:0) My DNS server on that vlan is statically configured as 2001:abc:ab23:2301::53 My phone when I connect gets a slacc address 2001:abc:ab23:2301:so.me:thi.ng I can't reach my DNS server from the outside world on 2001:abc:ab23:2301::53 because my firewall blocks it, but if I did allow it t would route through just fine Remember none of this works with v4 though, you'd have to configure your router to do nat46 and nat64. I've never used such a router, but looks like its supported https://docs.opnsense.org/manual/how-tos/tayga.html https://docs.opnsense.org/manual/how-tos/tayga.html As such if your public IPv4 was 23.45.67.89 address You'd forward 23.45:67.89 -> 2001:abc:ab23:2301::53 And vice versa. Now the next issue is multi-homing. My backup router is ipv4 only, so when 192.168.231.0/24 gets routed out my main ISP as normal, it's hidden behind an IP like 81.187.123.45. If I route traffic out of my backup 5g ISP it gets hidden behind that (it actually gets src-natted to a 10.x range, as it's a 4g ISP, it gets converted to a real public IP later) My 4g doesn't support ipv6, and ipv6 is just a toy, but I expect I would use nat66 to map 2001:abc:ab23:2301::53 behind whatever IP range I was given for the backup route. I've not looked into nat66. The other aspect is changing ISP. I don't plan on doing that, and ipv6 is only a toy protocol, hence I can just use my global address range. I could however use fd00:2301::53 for my internal DNS server (equivalent of 192.168.231.53) and nat66 it at the boundary, hiding fd00:2301:: behind 2001:abc:ab23:2301:: As the hide address is a /64 there's no need for port mapping, my traffic would emerge from 2001:abc:ab23:2301::53 ipv6 proponents talk about advertising half a dozen IPs to your end devices and renumbering them all dynamically and using mdns instead of static IPs. And they wonder why people thing ipv6 is crap.