I just upgraded two machines to Ubuntu 20.04 LTS and /var/log/syslog is full of:
systemd-resolved[...]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature level UDP.
with the only thing reported by tcpdump(8) as:
[...] [udp sum ok] 9797 NXDomain* q: AAAA? connectivity-check.ubuntu.com.[...]
The only thing that fixes it is by making connectivity-check.ubuntu.com fully qualified.
I have over 250 machines to upgrade. It all adds up.
I just upgraded two machines to Ubuntu 20.04 LTS and /var/log/syslog is full of:
systemd- resolved[ ...]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature level UDP.
with the only thing reported by tcpdump(8) as:
[...] [udp sum ok] 9797 NXDomain* q: AAAA? connectivity- check.ubuntu. com.[.. .]
The only thing that fixes it is by making connectivity- check.ubuntu. com fully qualified.
I have over 250 machines to upgrade. It all adds up.
Please append the dot.