Using a central controller cluster to configure a distributed multicast logical router

1. A method for a managed forwarding element (MFE) executing on a first host computer to implement a distributed multicast logical router, the method comprising:

receiving a multicast group report from a data compute node (DCN) that executes on the first host computer, the multicast group report indicating a multicast group that the DCN is joining;

sending a summarized multicast group report indicating multicast groups joined by DCNs executing on the first host computer to a set of central controllers;

receiving data based on an aggregated multicast group report from the set of central controllers, the aggregated multicast group report generated by the set of central controllers based on summarized group reports from a set of other hosts; and

using the data based on the aggregated multicast group report to configure the MFE to implement the distributed multicast logical router.

2. The method of claim 1 further comprising performing a snooping function on multicast group reports received by the MFE to determine multicast groups to include in the summarized multicast group report.

3. The method of claim 1 , wherein a summarized multicast group report sent by a particular host computer comprises (i) an identifier of the particular host computer and (ii) identifiers for the multicast groups joined by at least one DCN executing on the particular host computer.

4. The method of claim 3 , wherein the identifier of the particular host computer is at least one of an internet protocol (IP) address and a media access control (MAC) address.

5. The method of claim 4 , wherein the identifier of the particular host computer is an identifier of a tunnel endpoint executing on the particular host computer.

6. The method of claim 3 , wherein the identifiers for the multicast groups are internet protocol (IP) addresses associated with the multicast groups.

7. The method of claim 6 , wherein the multicast group report is sent from the DCN based on interest from an application executing on the DCN.

8. The method of claim 1 , wherein the aggregated multicast group report comprises an identifier for at least one multicast group and an identification of at least one host computer.

9. The method of claim 1 , wherein using the data based on the aggregated multicast group report to configure the MFE comprises using the data to populate a multicast forwarding table of the MFE.

10. The method of claim 9 further comprising using the multicast forwarding table to forward a received multicast data message for a particular multicast message group to only those hosts that have reported an interest in the particular multicast message group.

11. The method of claim 2 , wherein the snooping function is also used to populate a local output list identifying local DCNs that are interested in particular multicast message groups.

12. A non-transitory machine readable medium storing a program for a managed forwarding element (MFE) executing on a first host computer to implement a distributed multicast logical router, the program comprising sets of instructions for:

receiving a multicast group report from a data compute node (DCN) that executes on the first host computer, the multicast group report indicating a multicast group that the DCN is joining;

sending a summarized multicast group report indicating multicast groups joined by DCNs executing on the first host computer to a set of central controllers;

receiving data based on an aggregated multicast group report from the set of central controllers, the aggregated multicast group report generated by the set of central controllers based on summarized group reports from a set of other hosts; and

using the data based on the aggregated multicast group report to configure the MFE to implement the distributed multicast logical router.

13. The non-transitory machine readable medium of claim 12 , the program further comprising a set of instructions for performing a snooping function on multicast group reports received by the MFE to determine multicast groups to include in the summarized multicast group report.

14. The non-transitory machine readable medium of claim 12 , wherein a summarized multicast group report sent by a particular host computer comprises (i) an identifier of the particular host computer and (ii) identifiers for the multicast groups joined by at least one DCN executing on the particular host computer.

15. The non-transitory machine readable medium of claim 14 , wherein the identifier of the particular host computer is at least one of an internet protocol (IP) address and a media access control (MAC) address.

16. The non-transitory machine readable medium of claim 15 , wherein the identifier of the particular host computer is an identifier of a tunnel endpoint executing on the particular host computer.

17. The non-transitory machine readable medium of claim 14 , wherein the identifiers for the multicast groups are internet protocol (IP) addresses associated with the multicast groups.

18. The non-transitory machine readable medium of claim 17 , wherein the multicast group report is sent from the DCN based on interest from an application executing on the DCN.

19. The non-transitory machine readable medium of claim 12 , wherein the set of instructions for using the data based on the aggregated multicast group report to configure the MFE comprises a set of instructions for using the data to populate a multicast forwarding table of the MFE.

20. The non-transitory machine readable medium of claim 19 , wherein the program further comprises a set of instructions for using the multicast forwarding table to forward a received multicast data message for a particular multicast message group to only those hosts that have reported an interest in the particular multicast message group.