Futurewei Denpel Informatique Independent Intel Aruba-HPE This document describes virtual machine (VM) mobility solutions commonly used in data centers built with an overlay network. This document is intended for describing the solutions and the impact of moving VMs, or applications, from one rack to another connected by the overlay network. For layer 2, it is based on using an NVA (Network Virtualization Authority) to NVE (Network Virtualization Edge) protocol to update ARP (Address Resolution Protocol) tables or neighbor cache entries after a VM moves from an old NVE to a new NVE. For Layer 3, it is based on address and connection migration after the move.