Xangati recently released a VMware vSphere appliance that provides "video-like" visibility to your virtual network. Offered with a 14-day free trial, this appliance is able to view all traffic crossing your virtual network and allow you to monitor that traffic through sleek interface. Similar to a DVR that you would use to pause and rewind your TV shows, Xangati for ESX is able to offer the same "rewind feature" for your VMware infrastructure. The appliance understands the network traffic at the appliance level and shows you what VMs are talking to what. I believe that with Xangati for ESX and the visibility it provides, you can save a lot of time managing your virtual infrastructure network issues.