> Could you explain? How does it help to use IPv6 internally if you're using IPv4 publicly? See this presentation about IPv6 at Facebook: https://www.facebook.

> Could you explain? How does it help to use IPv6 internally if you're using IPv4 publicly? See this presentation about IPv6 at Facebook: https://www.facebook.com/groups/2234775539/10152303014725540/ https://www.facebook.com/groups/2234775539/10152303014725540... > IPv4 offers more than enough address space within its private ranges for your private network While theoretically true from a raw numbers standpoint, it breaks down at Facebook's scale when you have many gigantic data centers all over the world and start thinking about how you assign the addresses and manage the network that uses them. As the presentation says, there was lots of wastage due to racks being /24 and clusters being /n (where n < 24).