At the recent online Google network engineer Zhenya Linkova spoke about the project of transferring the Google corporate network to IPv6-only.
One of the stages was the transition of the guest network to IPv6 only. NAT64 was used to access the legacy Internet, and DNS64 on the public Google DNS was used as DNS. Of course, DHCP6 was not used, only SLAAC.
According to the results of testing, less than 5% of users switched to fall-back dual stack WiFi. As of July 2020, most Google offices have an IPv6-only guest network.
Available report.
Source: habr.com