On our systems at Hetzner we only have a single /64 IPv6 range, which we use to assign addresses to virtual systems, running in Xen and KVM. Because we don’t directly bridge the virtual machines to the external interface, we have written a script that synchronizes Neighbor Discovery entries to the external interface.

Today (June 8th) is World IPv6 Day, a day where some of the biggest network and website operators (Google, Bing, Facebook) turn on IPv6 for a full day to test drive a dual stack setup.