>Your router does not enable DHCPv6: Yes, I mentioned that in the initial report. >something has been tweaked (-> sysctl net.ipv6.conf.eno1) ... That isn't anything that I did (as far as I know). After disabling the firewall, with the suggested command, the system came up with IPv6 global addresses. But I'll need to repeat that to be sure, because occasionally there isn't a delay. I'll attach the output from the "sysctl" command.