The last years saw a rapid growth of virtualization technologies. Each virtual machine (VM) has one or more virtual interfaces with its unique characteristics such as MAC addresses. Typically, each VM network interface is connected to a virtual bridge on the host. Traffic between several VMs on one host is routed by a virtual bridge and stays within the host. However, some environments prefer to route this host internal traffic to an external switch so that network administrators are able to apply access and security rules between VMs as well. The IEEE 802.1Qbg standard, finalized July 5th 2012, addresses this requirement. It provides a frame relay service between the VMs and the adjacent bridge and defines methods and protocols to register VMs with external switches. This is achieved without modifying any network packet originated from a VM. Network administrators are now able to monitor VM traffic and apply access restrictions and bandwidth limitations. It provides a single point for management, network control and security and reduces complexity. The discussion describes the current state and the future work to be done to support more advanced data center specific hardware, for example SR-IOV cards. Discussions will include reliability features (bonding).
