MAC address learning and propagation in load balancing switch protocols

• US 6,556,541 B1
• Filed: 01/11/1999
• Issued: 04/29/2003
• Est. Priority Date: 01/11/1999
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Bare, Ballard C.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Elallam, Ahmed
• Application Number:
  US09/228,918
• Time in Patent Office: 1,569 Days
• Field of Search: 370/235, 370/236.1, 370/236.62, 370/237, 370/238, 370/238.1, 370/389, 370/390, 370/392, 370/395.31, 370/395.54, 370/396, 370/400, 370/410, 370/432
• US Class Current: 370/235
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/18 Loop-free operations
• CPC Class Codes: H04L 45/245 Link aggregation, e.g. trunking
• CPC Class Codes: H04L 45/48 Routing tree calculation
• CPC Class Codes: H04L 45/586 of virtual routers
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's
• CPC Class Codes: H04L 49/201 Multicast operation; Broadcast operation
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]

Abstract

A method for disseminating MAC addresses for discovered network devices through a plurality of network switches which cooperate to enable maintaining multiple active paths between such devices. Where a plurality of network switches cooperate through load balancing protocols to enable simultaneous use of multiple paths between, protocols of the present invention permit newly discovered MAC addresses attached to ports of an edge switch to be disseminated through the network switches. When an edge switch detects a device having a previously unknown MAC address, a MAC address information packet is generated and disseminated from the edge switch the other switched of the same load balance domain. The packet is preferably, in effect, broadcast using the pruned broadcast tree constructed and maintained by other protocols related to the present invention.

Claims

1. A method operable within at least one of a plurality of network switches for disseminating MAC address information, said method comprising the steps of:

receiving a message at a port of a switch of said plurality of network switches from a network device wherein said message includes a MAC address associated with said network device and wherein said switch is a member of a set of said plurality of networks switches which comprise a load balance domain;

generating a MAC address information packet within said switch in response to receipt of said message; and

broadcasting said MAC address information packet to at least one other port of said switch associated with said load balance domain.

2. The method of claim 1 wherein said switch is an edge switch of said load balance domain.

3. The method of claim 1 further comprising the step of:

forwarding said message to another of said plurality of network switches in response to broadcasting of said MAC address information packet.

4. The method of claim 3 further comprising the step of:

awaiting receipt of an acknowledgment of said MAC address information packet from each of said other ports of said switch in response to the step of broadcasting,

wherein the step of forwarding is further in response to the step of awaiting receipt of an acknowledgment.

5. The method of claim 1 wherein the step of broadcasting comprises the step of:

broadcasting said MAC address information packet to said at least one other port of said switch associated within said load balance domain in accordance with a pruned broadcast tree associated with said switch.

6. The method of claim 5 further comprising the steps of:

receiving the broadcast MAC address information packet on a port of another switch of said plurality of network switches; and

forwarding said packet to other ports of said another switch in accordance with said pruned broadcast tree.

7. The method of claim 5 further comprising the steps of:

updating MAC address tables within said another switch in accordance with said MAC address information packet; and

returning an acknowledgment message from said another switch to said switch indicative of the result of processing of said MAC address information packet within said another switch.

8. The method of claim 7 the step of returning said acknowledgment message comprises the step of:

returning said acknowledgment message indicative of successful processing of said MAC address information packet by said another switch; and

forwarding said packet to other ports of said another switch in accordance with said pruned broadcast tree.

9. The method of claim 7 wherein the step of updating includes the step of:

updating said MAC address tables in accordance with cost information associated with a sequence number in said MAC address information packet.

10. A system including a plurality of network switches each of said switches including a computer readable storage medium tangibly embodying a method operable within said plurality of network switches for disseminating MAC address information, said method comprising the steps of:

receiving a message at a port of a switch of said plurality of network switches from a network device wherein said message includes a MAC address associated with said network device and wherein said switch is a member of a set of said plurality of networks switches which comprise a load balance domain;

generating a MAC address information packet within said switch in response to receipt of said message; and

broadcasting said MAC address information packet to at least one other port of said switch associated with said load balance domain.

11. The system of claim 10 wherein said switch is an edge switch of said load balance domain.

12. The system of claim 10 wherein the method further comprises the step of:

forwarding said message to another of said plurality of network switches in response to broadcasting of said MAC address information packet.

13. The system of claim 12 wherein the method further comprises the step of:

awaiting receipt of an acknowledgment of said MAC address information packet from each of said other ports of said switch in response to the step of broadcasting,

wherein the step of forwarding is further in response to the step of awaiting receipt of an acknowledgment.

14. The system of claim 10 wherein the method step of broadcasting comprises the step of:

broadcasting said MAC address information packet to said at least one other port of said switch associated within said load balance domain in accordance with a pruned broadcast tree associated with said switch.

15. The system of claim 14 wherein the method further comprises the steps of:

receiving the broadcast MAC address information packet on a port of another switch of said plurality of network switches; and

forwarding said packet to other ports of said another switch in accordance with said pruned broadcast tree.

16. The system of claim 14 wherein the method further comprises the steps of:

updating MAC address tables within said another switch in accordance with said MAC address information packet; and

returning an acknowledgment message from said another switch to said switch indicative of the result of processing of said MAC address information packet within said another switch.

17. The system of claim 16 the method step of returning said acknowledgment message comprises the step of:

returning said acknowledgment message indicative of successful processing of said MAC address information packet by said another switch; and

forwarding said packet to other ports of said another switch in accordance with said pruned broadcast tree.

18. The method of claim 16 wherein the step of updating includes the step of:

updating said MAC address tables in accordance with cost information associated with a sequence number in said MAC address information packet.