For a VxRail 2 node cluster, it is not necessary to place the nodes at separate sites across geographic distance. This type of cluster can use a compatible vSAN witness at a third site, or a vSAN witness deployed local to the VxRail cluster.
As there are only two nodes in this cluster type, the VxRail management, vSAN, and VMware vSphere vMotion networks can be placed on Layer 2 networks between the nodes. If the vSAN witness is to be deployed local to the two VxRail nodes, Layer 2 can be used for the Witness Traffic Separation network. A vSAN witness at a remote site can also be considered to support a VxRail 2- node cluster.