Consideration | vSphere Port Group Backed | VXLAN Backed | VLAN-Backed | vCloud Network Isolation-Backed |
How it works | Isolated port groups must be created and exist on all hosts in cluster. | Multicast address is mapped to a VXLAN segment ID for isolation. Virtual machine to virtual machine traffic is tunneled over a Layer 3 network by a VTEP (ESXi hosts). Node learning done via multicast, not broadcast. | Uses range of available, VLANs dedicated for vCloud. Network isolation relies on inherent VLAN isolation. | Creates an overlay network (with fence ID) within a shared transport network. |
Advantages | N/A | Does not rely on VLAN IDs for isolation. Works over any Layer 3 multicast-enabled network. No “distance” restrictions, managed by multicast radius. | Best network performance. vCloud Director creates port groups as needed. | Scalable to create thousands of networks per transport network. More secure than VLAN backed option due to VCD enforcement. vCloud Director creates port groups as needed. |
Disadvantages | Requires manual creation and management of port groups. Possible to use a port group that is in fact not isolated. | End-to-end multicast required | VLANs are a limited commodity (4096 max). Requires used VLANs to be configured on all associated physical switches. Scoped to a single virtual datacenter and vCenter Server | Overhead required to perform encapsulation. |