Also, it is recommend to install the package: "apt-get install rdnssd", otherwise, Ubuntu will ignore the RDNSS from your Router Advertisement.
I have right now, a perfect IPv6-Only network, powered by "Router Advertisement with RDNSS" (from PFSense 2.1) and Ubuntu Servers 14.04, no need for DHCPv6!
Fixed in the latest Ubuntu 14.04!
Also, it is recommend to install the package: "apt-get install rdnssd", otherwise, Ubuntu will ignore the RDNSS from your Router Advertisement.
I have right now, a perfect IPv6-Only network, powered by "Router Advertisement with RDNSS" (from PFSense 2.1) and Ubuntu Servers 14.04, no need for DHCPv6!
Cheers!
Thiago