Virtualization - How to isolate application traffic

Many people are concerned with virtualization security (already coined VirtSec), and they're applying that concern from the virtual images all the way down the stack, to the network infrastructure through which virtualized application traffic is delivered.

The desire for network infrastructure to be itself virtualized is growing out of a perceived need to isolate application traffic at every point in the infrastructure. But the technology to isolate application traffic at layer 2 and 3 of the infrastructure already exists, and has been essentially virtualized for years.