Totally viable.. Been IPv6-only since Fall 2014 https://www.internetsociety.org/blog/2014/06/facebook-moving...

One of the benefits of /64 per host is there is no NDP since the only neighbor is your router.

Additionally you can install the routing software on server itself and let it form neighbor-ship with ToR router(s) and use ECMP directly from server in multi NIC scenarios. ECMP failover/recovery is faster and simpler (vendor agnostic) than link aggregation protocols. Basically each rack becomes its own OSPF totally stubby area. Data center core runs as area 0.

BIRD or other BGP on the host running VMs/containers is what Calico does. We had it peer with our ToR "switches" over BGP.

We could do zero downtime, 1 or 2 packets lost live migration of workloads from one hypervisor host to another and had full ECMP capabilities.

We did this with both IPv4 and IPv6. There is nothing special about IPv6, but it does make it easier to aggregate routes.

I'm speaking from the perspective of the router (or physical host) which must maintain NDP entries.

This is actually a huge change for Apple as iOS and OS X would only use IPv6 ~20% of the time because of the IPv4 bias the old algorithm used. After this change, I expect to see IPv6 at the level's we see at facebook with our app to approach 80%, which is a huge improvement and hopefully results in a good rise in IPv6 usage on the internet.

This is not true. Facebook has never attempted to migrate them to Linux. If WhatsApp wants to convert to Linux, it is their decision. More than likely they will stay on FreeBSD as that is what they know how to run and a good way to kill a product is to force them to do things instead of focusing on building their product.

A job posting in August indicates a failed migration attempt that couldn't have started until October, because that's when the transaction closed?