Network Security, Firewalls, and VPNs, 3rd Edition

What Are Virtual Firewalls?

The term virtual firewall describes a variety of firewall and firewall-like concepts. This can include virtualized software firewalls that provide filtering services for a standard physical network as well as firewalls running between virtualized client and server OSs. In theory, the use of a software firewall as a replacement for a network appliance could work as long as the host OSs network communication is routed through the virtual firewall before leaving the host’s network interface controller (NIC).

This is a relatively new and growing area for firewall deployment. Virtualization offers numerous benefits over a traditional, single OS to a single hardware box deployment. Virtualization allows for rapid development, ...