Disabling Opt.108 + PREFIX64
In January I decided to try running my home network with DHCP Option 108 (prefer IPv6) and a NAT64/DNS64 seup. Here’s what broke:
Homekit Stuff
Despite Apple’s splendid support for CLAT, peripherals around about the house were much less capable and presumably opted for IPv4. This then created a problem for devices like my phone (iOS), which would try to speak to these IPv4-only hosts through a CLAT-synthesized-IPv6 address that my router wouldn’t translate.
Bambu Printer
Bambu have been voluntarily jumping into hot water. But their dodgy behaviour aside - the printer seems to be IPv4 only. It only displays an IPv4 address, and it doesn’t seem to make itself known to IPv6-only hosts.
Which is a bit weird, isn’t it? I don’t really understand why, when you’re leveraging SSDP, you’d limit yourself to multicast on 239.255.255.250 instead of trying IPv6 link/site-local.
HONOR Android Tablet
Garbage. Garbo. Trash. Shite. A fundamentally broken and untested Android fork that sees option 108 and either chokes entirely because it can’t parse the DHCPOFFER, or understands option 108 and fails to configure the stack to operate in an IPv6-only mode. Whatever the fine details are, it is simply unusable without manually specifying an (IPv4) address.
EVE Front Door Camera
The EVE camera did work, but started behaving mysteriously. The flood-light would turn itself on, and then stay on forever. The preview of the camera in Apple Home would update when the application was opened - but viewing the camera wouldn’t work at all. Older clips taken by the camera worked without issue. Not the first time this system has been weird.
Epilogue
For now, I’ve set things back to how they were. Option 108 is off, RAD has stopped supplying the NAT64 prefix, and Unbound is no longer synthesizing AAAA records. I’d be inclined to try again in the future - Thread is built on IPv6, so a thermostat using that tech would certainly work on a IPv6-only network. The Eve camera, I think, is just buggy client software, rather than a lack of support.
HONOR should be liquidated.