It might be desirable to span WLD clusters across racks to avoid a single point of failure within one rack. The management VMs running on the Mgmt WLD cluster and any management VMs running on the VI WLD do require VxRail nodes to reside on the same L2 management network, so the VMs can be migrated between racks and maintain the same IP address. For a Layer 3 Leaf-Spine fabric, this is a problem as the VLANs are terminated at the leaf switches in each rack.

VxRail multi-rack cluster

VxRail multi-rack cluster is a network design that allows a single (or multiple) VxRail cluster(s) to span between racks. This particular solution uses a Dell networking switch hardware VTEP to provide an L2 overlay network to extend L2 segments over an L3 underlay network for VxRail node discovery, vSAN, vMotion, management, and VM/App L2 network connectivity between racks. The following diagram is an example of a multi-rack solution using hardware VTEP with VXLAN BGP EVPN. The advantage of VXLAN BGP EVPN over static VXLAN configuration is that each VTEP is automatically learned as a member of a virtual network from the EVPN routes received from the remote VTEP.

For more information about Dell Network solutions for VxRail, see the Dell EMC Networking Guides.

Figure 31.          Multi-Rack cluster with hardware VTEP