While server virtualization increases operational efficiencies and management flexibility, and reduces total cost of ownership, it can also increase security risks. According to Gartner, 60% of virtual machines (VM) will be less secure than their physical counterparts through 2009. The security challenges include: * IP address dependency: In a virtualized environment, IP addresses often change as VMs are created, retired or migrated from one physical host to another, causing problems in traditional protection mechanisms. * Virtual machine sprawl: VMs are easily created from previously existing images, often introducing a large number of VMs that are not properly maintained or are based on images with known vulnerabilities. Successful attacks on vulnerable VMs can serve as a launch pad to attack other virtual machines. * Inability to monitor intrahost traffic: Server virtualization introduces the concept of a “soft switch” to allow VMs to communicate with each other inside a single host. Special tools are required to monitor and protect these communications, and options are limited.