Providing cloud-based services using dynamic network virtualization

1. A method of providing a cloud-based service over a packet switching network via a system having a dynamic network virtualization architecture comprising a plurality of forwarding elements controlled by a central controller and a plurality of virtual machines, each said virtual machine being associated with one of the forwarding elements, the method comprising:

receiving, at a first forwarding element, a data packet of said service;

determining, by the first forwarding element, whether the data packet of said service is destined for at least one of the plurality of virtual machines locally bounded to the first forwarding element, the data packet of said service is destined for at least one of the plurality of virtual machines not locally bounded to the first forwarding element and the data packet of said service is destined for at least one of the plurality of virtual machines external to the packet switching network;

determining, by the first forwarding element, a destination of the data packet based on which of the plurality of locations the data packet of said service is destined;

forwarding, responsive to said destination being a virtual machine associated with the first forwarding element, the data packet directly to the virtual machine.

2. The method of claim 1 , wherein forwarding comprises:

forwarding, responsive to said virtual machine being associated with a second forwarding element, the data packet to the virtual machine via the second forwarding element.

3. The method of claim 2 , wherein forwarding further comprises:

forwarding, responsive to the destination being external to said architecture, the data packet to the destination in accordance with an external forwarding table of the first forwarding element.

4. The method of claim 2 , wherein forwarding further comprises:

forwarding the data packet to the second forwarding element via one of: a tunneled connection between the first and second forwarding elements, a multiprotocol label switched path between the first and second forwarding elements, or dedicated facilities between the first and second forwarding elements.

5. The method of claim 1 , further comprising:

advertising, by the first forwarding element, an address of the virtual machine to a system of the packet switching network that is external to said architecture.

6. The method of claim 5 , wherein advertising is controlled by the central controller.

7. The method of claim 1 , further comprising prior to determining:

discovering, by the first forwarding element, the virtual machine;

receiving, by the first forwarding element, registration from the virtual machine, thereby causing said virtual machine to be associated with the first forwarding element;

sending, by the first forwarding element, to the central controller an indication of an association so formed between said virtual machine and the first forwarding element.

8. The method of claim 7 , further comprising

storing, by the first forwarding element, an internal forwarding table;

receiving, by the first forwarding element, an update to the internal forwarding table from the central controller.

9. The method of claim 7 , wherein receiving registration comprises:

receiving, by the first forwarding element, a first registration message from the virtual machine.

10. The method of claim 9 , further comprising:

sending, by a third forwarding element to which the virtual machine was formerly associated, a second registration message to systems in a subnet to which the third forwarding element belongs to indicate that the third forwarding element will act as a proxy for the virtual machine.

11. The method of claim 10 , wherein the first and second registration messages are address resolution protocol messages.

12. The method of claim 7 , wherein registering further comprises:

determining whether or not a security policy of the central controller will be violated by registering the virtual machine.

13. A system for providing a cloud-based service over a packet switching network, comprising:

a plurality of forwarding elements configured to route data packets of said service and determine whether the data packet of said service is destined for at least one of the plurality of virtual machines locally bounded to the first forwarding element, the data packet of said service is destined for at least one of the plurality of virtual machines not locally bounded to the first forwarding element and the data packet of said service is destined for at least one of the plurality of virtual machines external to the packet switching network;

determine which of a plurality of locations including internal to the packet switching network and external to the packet switching network, the data packet of said service is destined;

a central controller configured to control the plurality of forwarding elements in routing the data packets; and

a virtual machine configured to process data packets of said service, the virtual machine being associated with a first forwarding element of the plurality of forwarding elements.

14. The system of claim 13 , further comprising:

a plurality of connections interconnecting the plurality of forwarding elements such that each forwarding element is connected to at least one other forwarding element.

15. The system of claim 14 , wherein at least one connection of the plurality of connections is one of: a tunneled connection, a multiprotocol label switched path, or a dedicated facilities connection.

16. The system of claim 14 , wherein the first forwarding element comprises an indication of the virtual machine being associated with the first forwarding element.

17. The system of claim 16 , wherein a second forwarding element of the plurality of forwarding elements comprises said indication.

18. The system of claim 17 , wherein each of the first and second forwarding elements further comprises a respective forwarding table in which said indication is stored along with routing information for sending a data packet of said service to the virtual machine.

19. The system of claim 18 , wherein the central controller is operable to configure the respective forwarding tables on the first and second forwarding elements with said routing information.

20. The system of claim 13 , wherein the virtual machine is operable to register itself with the first forwarding element thereby causing the virtual machine to be associated with the first forwarding element.

21. The system of claim 20 , wherein the first forwarding element is operable to convey an indication to the central controller.

22. The system of claim 21 , wherein the central controller is further operable to configure said indication on the second forwarding element.

23. The system of claim 22 , further comprising a plurality of virtual machines wherein each virtual machine is associated with one of the forwarding elements.