In Red Hat Virtualization, a virtual machine has its NIC put on a logical network at the time that the virtual machine is created. From that point, the virtual machine is able to communicate with any other destination on the same network.
From the host perspective, when a virtual machine is put on a logical network, the VNIC that backs the virtual machine's NIC is added as a member to the bridge device for the logical network. For example, if a virtual machine is on the
ovirtmgmt logical network, its VNIC is added as a member of the
ovirtmgmt bridge of the host on which that virtual machine runs.