Tags: dns, network, azure, ubuntu
TABLE OF CONTENTS
A widespread outage was caused on Azure instances, when systemd 237-3ubuntu10.54 was published to the bionic-security pocket. Instances could no longer resolve DNS queries, breaking networking.
The issue is documented as the following Ubuntu bug: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1988119
For affected users, the following workarounds are available. Use whatever is most convenient.
1. Reboot your instances
2. Issue "udevadm trigger -cadd -yeth0 && systemctl restart systemd-networkd" command as root