Huawei Huawei Server virtualization allows one physical server to support many virtual machines (VMs) so that multiple hosts (20, 30, or hundreds) can be running from one physical platform. As virtual machines are introduced into a Data Center, the number of hosts within the data center can grow dramatically, which can have tremendous impact on the network and hosts. This document provides an analysis of the scalability of IPv6 Neighbor Discovery (RFC 4861) in data centers with a large number of virtual machines.