I'm facing the following rather strange issue with my DIY NAS running Ubuntu 18.04.
(I think that's when this happens...) When the system is restarted (say, after a power failure) it sometimes isn't able to perform any DNS resolution.
Restarting the system manually typically brings the situation back to normal.
When name resolution is broken I have the following:
- systemd-resolve --status says "Current Scopes: none" (instead of "DNS")
- /run/systemd/resolve/resolv.conf says "# No DNS servers known.", whereas in the normal situation it contains "nameserver fe80::7e03:d8ff:feac:3cd4%3"
What could explain that the DNS resolver sometimes doesn't properly initialize at startup (pointing at my ISP's FTTH router's DNS)?