User-configured on-demand virtual layer-2 network for infrastructure-as-a-service (IaaS) on a hybrid cloud network

A method comprising:

• storing in a configuration database virtual network addresses and physical network addresses for a plurality of nodes in a virtual network, the virtual network overlaid upon a plurality of physical networks that include an Internet that routes data using a layer-3 Internet Protocol (IP) network address;
• receiving network-configuration requests from a client operated by a subscriber, for writing a new virtual network address and a new physical network address for a new node being added to the virtual network, wherein applications executing on the new node send data to other nodes in the plurality of nodes using the virtual network addresses and receive data from the virtual network addressed to the new virtual network address;
• storing in a virtual network switch table on each node entries for nodes in the virtual network, the entries including a virtual network address and a physical network address for each node on the virtual network;
• sending updates of the configuration database from a configuration controller to the plurality of nodes in the virtual network when the configuration database is updated;
• at a virtual network management daemon running on each of the plurality of nodes, receiving the updates from the configuration controller and writing the updates to the virtual network switch table at the corresponding node;
• at a node among the plurality of nodes:
• sending data, from a network stack, to an application executing on the node when a virtual network address of an incoming packet matches a virtual network address of the node, and the network stack receives data from the application and sends the data to a virtual network address specified by the application;
• receiving, at a network interface controller, data matching a physical network address for the node and sending data to the physical network address;
• and
• intercepting, with a virtual network device driver shim, a virtual network address from the network stack and encapsulating data with a physical network address sent to the network interface controller using the virtual network switch table such that data sent to virtual network addresses of the network stack are encapsulated using physical network addresses of a physical local-area network that routes data using a layer-2 physical network address by the virtual network device driver shim looking up a translation in the virtual network switch table, wherein the physical local-area network is connected to the Internet.

An apparatus comprising:

• a network interface controller (NIC), coupled to a physical local-area network that routes data using a layer-2 physical network address, configured to receive data matching a physical network address from a node in a virtual network overlaid upon a plurality of physical networks that include an Internet that routes data using a layer-3 Internet Protocol (IP) network address, and for sending data to a physical network address;
• memory configured to store a virtual network switch table containing entries for nodes on the virtual network, the entries including a virtual network address and a physical network address for each node on the virtual network;
• a processor coupled to the NIC and the memory, and configured to execute:
• a network stack configure to send data to an application executing on the node when a virtual network address of an incoming packet matches a virtual network address of the node, to receive data from the application and sends the data to a virtual network address specified by the application;
• and
• a device driver shim that intercepts a virtual network address from the network stack and encapsulate packets using physical network addresses of the physical local-area network using the VN switch table to retrieve physical network addresses from corresponding virtual network addresses of the packets.