IPv6 duplicate address and dadfailed
Written by: Ilya Vasilenko on 29 January 2020 03:54 PM
Solving the issue with IPv6 when DAD is failed
Edit the file /etc/sysctl.conf and insert following lines into it:
Where "eth0" is your Ethernet interface name.
And restart networking:
service network restart
service networking restart
Or just reboot the VPS.