NetFlow itself is a networking protocol that collects IP traffic information as records and sends them to a collector such as CA NetQoS for traffic flow analysis. VMware vSphere 5 supports NetFlow v5, which is the most common version supported by network devices. NetFlow capability in the vSphere 5 platform provides visibility into virtual infrastructure traffic that includes :
• Intrahost virtual machine traffic (virtual machine–to–virtual machine traffic on the same host)
• Interhost virtual machine traffic (virtual machine–to–virtual machine traffic on different hosts)
• Virtual machine to physical infrastructure traffic
Hope this helped
Best regards
Your Oscar