Virtual Firewall is a term that refers to the firewalls that are responsible for monitoring and filtering of virtual machine’s network traffic in a Virtual Area Network (VAN) environment.
Virtual Firewalls are installed and executed over the virtual networks. They are specifically dedicated for the monitoring of network traffic over the virtual machines only. Virtual Firewalls filter the incoming and outgoing traffic over the network and performs required actions, like blocking some traffic or denying some access, according to the security scenarios. These Virtual Firewalls have two basic operating modes i.e. Bridge mode and Hypervisor mode. In Bridge mode, Virtual Firewall monitors the incoming and outgoing traffic from and to other virtual machines residing over the same virtual network. Whereas, in Hypervisor mode, Virtual Firewalls reside in the kernel of Operating System (OS) of the virtual machine and only monitors the incoming and outgoing traffic of it’s host virtual machine.