Pro-active mechanism to detect LISP movable silent host

1. A method comprising:

receiving, at a network device, a registration from each of a plurality of endpoint routers to associate each of the plurality of endpoint routers with a dynamic endpoint identifier range, wherein the dynamic endpoint identifier range is associated with a plurality of silent hosts that do not register with any of the plurality of endpoint routers when connected to one or more of the plurality of endpoint routers;

receiving, from a first endpoint router at the network device, a request seeking a location identifier for an endpoint identifier of one of the plurality of silent hosts;

determining that the endpoint identifier belongs to the dynamic endpoint identifier range associated with each of the plurality of endpoint routers;

forwarding the request to the plurality of endpoint routers to discover a host having the endpoint identifier;

receiving a notification from one of the plurality of endpoint routers reporting discovery of the host having the endpoint identifier; and

sending an identifier of the one of the plurality of endpoint routers which reports discovery of the host to the first endpoint router as the location identifier for the endpoint identifier.

2. The method of claim 1 , further comprising:

storing data for the registrations to associate the dynamic endpoint identifier range with each of the plurality of endpoint routers.

3. The method of claim 1 , wherein the network device is a mapping server implementing a Locator/identifier (ID) Separation Protocol (LISP), and the first endpoint router and the plurality of endpoint routers are LISP routers.

4. The method of claim 3 , wherein the request is a map request and the notification is a map notify in a LISP network, and the plurality of endpoint routers are configured to use Address Resolution Protocol (ARP) to discover the host having the endpoint identifier.

5. The method of claim 3 , wherein the host having the endpoint identifier is a virtual machine and is movable between different sites attached to different endpoint routers of the plurality of endpoint routers.

6. The method of claim 3 , wherein the host is a silent host that does not advertise its location or register itself with the mapping server.

7. The method of claim 1 , wherein the dynamic endpoint identifier range is a subnet defined by a subnet mask.

8. An apparatus comprising:

one or more network ports to send and receive data packets to and from a communication network; and

a processor coupled to the network ports, and configured to:

receive a registration from each of a plurality of endpoint routers to associate each of the plurality of endpoint routers with a dynamic endpoint identifier range, wherein the dynamic endpoint identifier range is associated with a plurality of silent hosts that do not register with any of the plurality of endpoint routers when connected to one or more of the plurality of endpoint routers;

receive, from a first endpoint router, a request seeking a location identifier for an endpoint identifier of one of the plurality of silent hosts;

determine that the endpoint identifier belongs to the dynamic endpoint identifier range associated with each of the plurality of endpoint routers;

forward the request to the plurality of endpoint routers to discover a host having the endpoint identifier;

receive a notification from one of the plurality of endpoint routers reporting discovery of the host having the endpoint identifier; and

send an identifier of the one of the plurality of endpoint routers which reports discovery of the host to the first endpoint router as the location identifier for the endpoint identifier.

9. The apparatus of claim 8 , wherein the processor is further configured to:

store data for the registrations to associate the dynamic endpoint identifier range with each of the plurality of endpoint routers.

10. The apparatus of claim 8 , wherein the apparatus is a mapping server implementing a Locator/identifier (ID) Separation Protocol (LISP), and the first endpoint router and the plurality of endpoint routers are LISP routers.

11. The apparatus of claim 10 , wherein the request is a map request and the notification is a map notify in a LISP network, and the plurality of endpoint routers are configured to use Address Resolution Protocol (ARP) to discover the host having the endpoint identifier.

12. The apparatus of claim 10 , wherein the host having the endpoint identifier is a virtual machine and is movable between different sites attached to different endpoint routers of the plurality of endpoint routers.

13. The apparatus of claim 10 , wherein the host is a silent host that does not advertise its location or register itself with the mapping server.

14. The apparatus of claim 8 , wherein the dynamic endpoint identifier range is a subnet defined by a subnet mask.

15. A non-transitory computer readable storage media encoded with instructions that, when executed by a processor of a network device, cause the processor to:

receive a registration from each of a plurality of endpoint routers to associate each of the plurality of endpoint routers with a dynamic endpoint identifier range, wherein the dynamic endpoint identifier range is associated with a plurality of silent hosts that do not register with any of the plurality of endpoint routers when connected to one or more of the plurality of endpoint routers;

receive, from a first endpoint router, a request seeking a location identifier for an endpoint identifier of one of the plurality of silent hosts;

determine that the endpoint identifier belongs to the dynamic endpoint identifier range associated with each of the plurality of endpoint routers;

forward the request to the plurality of endpoint routers to discover a host having the endpoint identifier;

receive a notification from one of the plurality of endpoint routers reporting discovery of the host having the endpoint identifier; and

send an identifier of the one of the plurality of endpoint routers which reports discovery of the host to the first endpoint router as the location identifier for the endpoint identifier.

16. The non-transitory computer readable storage media of claim 15 , further comprising instructions to cause the processor to:

store data for the registrations to associate the dynamic endpoint identifier range with each of the plurality of endpoint routers.

17. The non-transitory computer readable storage media of claim 15 , wherein the network device is a mapping server implementing a Locator/identifier (ID) Separation Protocol (LISP), and the first endpoint router and the plurality of endpoint routers are LISP routers.

18. The non-transitory computer readable storage media of claim 17 , wherein the request is a map request and the notification is a map notify in a LISP network, and the plurality of endpoint routers are configured to use Address Resolution Protocol (ARP) to discover the host having the endpoint identifier.

19. The non-transitory computer readable storage media of claim 17 , wherein the host having the endpoint identifier is a virtual machine and is movable between different sites attached to different endpoint routers of the plurality of endpoint routers, and wherein the host is a silent host that does not advertise its location or register itself with the mapping server.

20. The non-transitory computer readable storage media of claim 15 , wherein the dynamic endpoint identifier range is a subnet defined by a subnet mask.