Enhancing VM Mobility with VxLAN, OVSDB and EVPN

Organizations are increasingly using virtual machine mobility to optimize server resources, ensure application performance and to aid in disaster avoidance. Typically VM live migration has relied on increasing the scale of the L2 broadcast domain to ensure that the VMs can be reached after migrations using their current addressing. This has resulted in the increasing use of VLANs and the need for L2 extension over the WAN.  As a result organizations are looking for ways overcome the limitations with VLAN scale and for methods to extend the L2 domain over the WAN that ensure the best performance. VxLAN has emerged as an alternative technology to VLANs, and EVPN has emerged at a better way to transport VMs over the WAN. Together these technologies can enable VM live migration over the WAN, or long distance vMotion in VMware parlance, but they need to all work together effectively and this is where OSVDB, VxLAN routing and a new technology from Juniper called ORE come in to play.

VxLAN Increases VLAN Scale
Organizations are increasingly looking to VxLAN as a solution. The primary goals behind this network architecture is to increase traditional VLAN limits from 4,094 and to enable VM mobility across Layer 3 subnets. VxLAN is a tunneling technology and is used to create an overlay network so that virtual machines can communicate with each other and to enable the migration of VMs both within a data center and between data centers. VxLAN enables multi-tenant networks at scale, as a component of these logical, software-based networks that can be created on-demand. VxLAN enables enterprises to leverage capacity wherever it’s available by supporting VM live migration. VxLAN implements a Layer 2 network isolation technology using MAC in IP encapsulation that uses a 24-bit segment identifier to scale beyond the 4K limitations of VLANs.