Method of detecting errors in a network

• US 6,052,733 A
• Filed: 10/01/1997
• Issued: 04/18/2000
• Est. Priority Date: 05/13/1997
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Mahalingam, Mallikarjunan, Wallach, Walter August
• Primary Examiner(s): HUA, LY
• Application Number:
  US08/940,302
• Time in Patent Office: 930 Days
• Field of Search: 714/25, 714/43, 714/3, 714/4, 714/24, 714/48, 709/235, 709/223
• US Class Current: 709/235
• CPC Class Codes: G06F 1/20 Cooling means
• CPC Class Codes: G06F 1/206 comprising thermal management
• CPC Class Codes: G06F 13/4027 using bus bridges G06F13/4022 takes precedence
• CPC Class Codes: G06F 13/4081 Live connection to bus, e.g. hot-plugging current or voltage limitation during live insertion H02H9/004
• CPC Class Codes: H04L 12/40195 by using a plurality of nodes
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 45/58 Association of routers
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/10015 Access to distributed or replicated servers, e.g. using brokers
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method is described for providing fault tolerance within a computer system. The method allows multiple network interface cards to reside within the same computer system. If a primary network interface card fails, a secondary network interface card automatically begins managing the network communications. In addition, a method of load-sharing data transmissions between each network interface card installed in a server computer is described.

Claims

1. A method of load balancing network traffic between a plurality of network interface cards, comprising:

a) determining the address of a primary network interface card (NIC) and a secondary NIC in a computer system;

b) binding said primary NIC and secondary NIC into a group; and

c) routing a portion of the data packets sent to the address of said primary NIC to the address of said secondary network interface card.

2. The method of claim 1, wherein said method of determining the address of a primary NIC comprises the method of determining the Media Access Control address of said primary NIC.

3. The method of claim 1, wherein said binding said primary NIC and said secondary NIC comprises the method of binding said primary NIC and said secondary NIC into a MULTISPAN group.

4. The method of claim 1, wherein said method of binding said primary NIC and said secondary NIC into a group comprises the method of identifying each NIC in the group with the address of said primary NIC.

5. The method of claim 1, wherein said method of routing a portion of said data packets comprises the method of removing the MAC address of said data packet and replacing it with a different MAC address.

6. An apparatus for load balancing traffic on a network between a plurality of network interface cards (NICs) in a computer, the computer including a program for sending a plurality of data packets over the network, the plurality of NICs including at least a first NIC and a second NIC, the apparatus comprising:

means for determining an address corresponding to each NIC in the plurality of NICs;

means for binding the plurality of NICs into a group using the address corresponding to each NIC in the plurality of NICs; and

means for routing a portion of the plurality of data packets addressed to the first NIC by the program to at least the second NIC in the group for transmission over the network.

7. The apparatus of claim 6, wherein each of the data packets in the portion of the plurality of data packets includes a source media access control (MAC) address, and the means for routing further comprises means for modifying the source MAC address in each of the data packets in the portion of the plurality of data packets to indicate the second NIC.

8. The apparatus of claim 6, further comprising:

means for receiving a second packet addressed to the second NIC from the network, the second packet including a destination MAC address; and

means for modifying the destination MAC address to indicate the first NIC.

9. The apparatus of claim 6, further comprising means for responding to a failure of the first NIC by routing all of the plurality of data packets to the second NIC for transmission over the network.

10. A computer program for load balancing traffic on a network between a plurality of network interface cards (NICs) in a computer, the plurality of NICs including at least a first NIC and a second NIC, the computer program comprising:

a first set of instructions for intercepting a data packet sent by a second computer program to the first NIC for transmission over the network, the data packet including a source media access control (MAC) address corresponding to the first NIC;

a second set of instructions for selecting the second NIC in the plurality of NICs according to usage of the plurality of NICs;

a third set of instructions for setting the source MAC address in the data packet to correspond to the second NIC; and

a fourth set of instructions for forwarding the data packet to the second NIC.

11. The computer program of claim 10, wherein the second set of instructions further comprises a fifth set of instructions for round-robin usage of each of the plurality of NICs.

12. The computer program of claim 10, wherein each of the plurality of NICs has a corresponding status of one of enabled and disabled, and wherein the second set of instructions further comprises a fifth set of instructions for round-robin usage of each of the plurality of NICs with a corresponding status of enabled.

13. The computer program of claim 10, further comprising:

a fifth set of instructions for receiving a second data packet from one of the plurality of NICs, the second data packet including a destination MAC address corresponding to one of the plurality of NICs;

a sixth set of instructions for setting the destination MAC address in the data packet to correspond to the first NIC; and

a seventh set of instructions for forwarding the second packet to a second program.

14. An server computer comprising:

a plurality of network interface cards (NICs), each of the plurality of NICs capable of being coupled to respective networks, the plurality of NICs including at least a first NIC and a second NIC;

a memory, the memory comprising

a plurality of programs, each program in the plurality of programs controlling respective NICs in the plurality of NICs to transmit data packets for the respective NIC over the respective network,

a first program, the first program generating a data packet for the first NIC, the data packet including a source address, and

a second program intercepting the data packet, selecting the second NIC in the plurality of NICs in a round-robin order, modifying the source address to correspond to the second NIC and sending the packet to the respective program in the plurality of programs for the second NIC; and

a processor, the processor executing the first program, the plurality of programs and the second program.

15. The server computer of claim 14, wherein the second program intercepting a second data packet including a destination address received on a third NIC in the plurality of NICs, modifying the destination address to correspond to the first NIC, and sending the packet to the first program.

16. The server computer of claim 14, wherein the memory further comprises a corresponding status for each NIC in the plurality of NICs, the corresponding status one of enabled and disabled, and wherein the second program selecting a second NIC in the plurality of NICs in round-robin fashion comprises verifying that the corresponding status of the second NIC is enabled.

17. The server computer of claim 14, wherein the second program is a Netware loadable module (NLM) comprising a prescan driver.

18. The server computer of claim 14, wherein the second program is an intermediate driver.

19. The server computer of claim 14, wherein the first program is Netware loadable module.