In a SmartFabric-based network, the transition from a single rack to multi-rack requires the deployment of a minimum of two qualified Dell EMC switches at the spine layer to interconnect the leaf switches in the individual racks. Each leaf switch requires a cable connection to each spine switch.
When the spine switches are enabled for SFS, they are discovered by the master switch in the fabric. As part of their integration into the switch fabric, VxLAN tunnels are automatically set up for Layer 2 extensions between racks using Layer 3 VLAN over an eBGP underlay network and EVPN overlay network. Specific networks, such as those used by the VxRail cluster, are automatically added to the VxLAN tunnel network by SFS integration with VxRail Manager. Virtual networks can also be manually configured as a day 2 operation with the OMNI plug-in. This VxLAN-based tunnel network enables nodes in a VxRail cluster to reside in different physical racks, and be discovered by VxRail Manager across racks.
Figure 10. VxLAN tunnel network for SmartFabric multi-rack deployments