5.2. Physical Network Configuration
By default CloudStack will use the device that is used for the default route. This device will be placed in a CloudStack-created bridge. This guide assumes that only a single NIC will be configured and cabled, and that if you have multiple KVM hosts that the same NIC will be configured across all the hosts.
Coverage of multiple NIC, bonded NIC, and other more complex networking scenarios are covered in the Install Guide