I can confirm that IPv6 on Ubuntu 15.10 is basically broken out of the box... at least, the DHCPv6 is broken out of the box due to this issue. The workaround of setting disable_dad worked for me, described at https://www.agwa.name/blog/post/beware_the_ipv6_dad_race_condition
I can confirm that IPv6 on Ubuntu 15.10 is basically broken out of the box... at least, the DHCPv6 is broken out of the box due to this issue. The workaround of setting disable_dad worked for me, described at https:/ /www.agwa. name/blog/ post/beware_ the_ipv6_ dad_race_ condition