REQUESTING MULTICAST MEMBERSHIP INFORMATION IN A DISTRIBUTED SWITCH IN RESPONSE TO A MISS EVENT

• US 20130182706A1
• Filed: 01/18/2012
• Published: 07/18/2013
• Est. Priority Date: 01/18/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Angst, Debra L., Basso, Claude, Cors, Josep, Greenfield, Todd A., Vaidhyanathan, Natarajan
• Granted Patent: US 8,861,400 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/44 Distributed routing

Abstract

Apparatuses and methods to request multicast membership information in a distributed switch are provided. A particular method may include requesting multicast membership information of a group identified by a multicast destination address in a distributed switch. The distributed switch may include a plurality of distributed switch elements with a plurality of switch forwarding units. The method may generate a miss event indicating that the multicast destination address is unregistered in a switch forwarding unit of a distributed switch element and there is a need for the multicast membership information. The method may also request the multicast membership information of the multicast destination address in response to the miss event. The method may further initiate a query for the multicast membership information of the multicast destination address in response to the request.

Claims

1. A method of requesting multicast membership information of a group identified by a multicast destination address in a distributed switch, wherein the distributed switch includes a plurality of distributed switch elements with a plurality of switch forwarding units, the method comprising:

generating a miss event indicating that the multicast destination address is unregistered in a switch forwarding unit of a distributed switch element and there is a need for the multicast membership information;

requesting the multicast membership information of the multicast destination address in response to the miss event; and

initiating a query for the multicast membership information of the multicast destination address in response to the request.

2. The method of claim 1, wherein the query is a group specific query soliciting at least one host that is a member of the group identified by the multicast destination address for the multicast membership information.

3. The method of claim 1, wherein the query is a general query soliciting substantially all hosts attached to the distributed switch to provide substantially all multicast membership information for substantially all multicast destination addresses.

4. The method of claim 1, wherein the query is initiated by a master distributed switch element of the distributed switch.

5. The method of claim 1, wherein the query is initiated by a slave distributed switch element of the distributed switch.

6. The method of claim 1, further comprising forwarding the query to at least one host.

7. The method of claim 1, further comprising receiving the multicast membership information in response to the query from at least one host.

8. The method of claim 7, further comprising programming the switch forwarding unit with the multicast membership information received in response to the query.

9. The method of claim 8, further comprising forwarding multicast data sent to the multicast destination address to at least one host identified by the multicast membership information received in response to the query.

10. The method of claim 1, further comprising:

determining whether the multicast membership information of the multicast destination address is in a global forwarding table; and

initiating the query when the multicast membership information is not in the global forwarding table.

11. An apparatus comprising:

at least one processor; and

program code configured to be executed by the processor to request multicast membership information of a group identified by a multicast destination address in a distributed switch, wherein the distributed switch includes a plurality of distributed switch elements with a plurality of switch forwarding units by;

generating a miss event indicating that the multicast destination address is unregistered in a switch forwarding unit of a distributed switch element and there is a need for the multicast membership information;

requesting the multicast membership information of the multicast destination address in response to the miss event; and

initiating a query for the multicast membership information of the multicast destination address in response to the request.

12. The apparatus of claim 11, wherein the query is a group specific query soliciting at least one host that is a member of the group identified by the multicast destination address for the multicast membership information.

13. The apparatus of claim 11, wherein the query is a general query soliciting substantially all hosts attached to the distributed switch to provide substantially all multicast membership information for substantially all multicast destination addresses.

14. The apparatus of claim 11, wherein the query is initiated by a master distributed switch element of the distributed switch.

15. The apparatus of claim 11, wherein the query is initiated by a slave distributed switch element of the distributed switch.

16. The apparatus of claim 11, wherein the program code is configured to receive the multicast membership information in response to the query from at least one host.

17. The apparatus of claim 16, wherein the program code is configured to program the switch forwarding unit with the multicast membership information received in response to the query.

18. The apparatus of claim 17, wherein the program code is configured to forward multicast data sent to the multicast destination address to at least one host identified by the multicast membership information received in response to the query.

19. The apparatus of claim 11, wherein the program code is configured to:

determine whether the multicast membership information of the multicast destination address is in a global forwarding table; and

initiate the query when the multicast membership information is not in the global forwarding table.

20. A method of requesting multicast membership information of a group identified by a multicast destination address in a distributed switch, wherein the distributed switch includes a plurality of distributed switch elements with a plurality of switch forwarding units, the method comprising:

initiating a query for the multicast membership information of the multicast destination address in response to a miss event indicating that the multicast destination address is unregistered in a switch forwarding unit of a distributed switch element and there is a need for the multicast membership information;

receiving the multicast membership information in response to the query from at least one host;

snooping the multicast membership information received in response to the query; and

programming the switch forwarding unit with the snooped multicast membership information.