Getting CLAT to work on macOS on Chromium based browsers
I'm doing some work with NAT64/PREF64 on my network and there's something wrong with chromium based browsers in macOS.
To clarify, I don't use DNS64, just NAT64/PREF64 and CLAT manually enabled in macOS (by setting IPv4 to Off in Network settings). With this setup, CLAT works just fine, I have system level access (like ping) to IPv4 only addresses and Safari browser successfully accesses IPv4 only websites with the NAT64 prefix sent via PREF64.
Problem seems to be that Chromium based browsers seem to have their own DNS stack and they ignore the system level CLAT and just not load IPv4 only websites at all. If I enable DNS64 on my network, those browsers work just fine, but without DNS64 it's not sending the request to the system to synthesize the IPv6 address of the IPv4 only website.
This setup (CLAT/NAT64/PREF64 no DNS64) works just fine Linux (Fedora) with Chromium browsers, so there's definitely a flag or something that I can trigger in these browser to either synthesize the IPv6 themselves or just send the request to the system and let it do it (like Safari does).
Any ideas?