Method and apparatus for implementing a MAC address pool for assignment to a virtual interface aggregate

• US 6,928,478 B1
• Filed: 06/25/2001
• Issued: 08/09/2005
• Est. Priority Date: 06/25/2001
• Status: Active Grant

• Current Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Gangadharan, SushilKumar
• Primary Examiner(s): Barot, Bharat
• Application Number:
  US09/888,778
• Time in Patent Office: 1,506 Days
• Field of Search: 709200-203, 709225-228, 709/245, 709249-250, 370389-393, 370/401, 370/475
• US Class Current: 709/226
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 2101/677 Multiple interfaces, e.g. multihomed nodes
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A technique implements a MAC address pool containing a plurality of unique MAC addresses adapted for assignment to a virtual interface or aggregate of a server in a computer network. The MAC address pool is created from original MAC addresses assigned to physical interfaces of a network interface card (NIC) that is used in the server. The physical interfaces and their underlying physical links are organized as the aggregate. Upon system initialization, a virtual interface process of the server collects the originally assigned MAC addresses of the NIC, modifies them and organizes them as a pool. Each originally assigned MAC address is modified by asserting its locally administered bit. Each modified MAC address is a distinct MAC address that does not conflict with other MAC addresses within, e.g., a local area network of the computer network.

Claims

1. A method for implementing an address pool containing a plurality of unique addresses adapted for assignment to an aggregate of a server in a computer network, the method comprising the steps of:

collecting addresses originally assigned to physical interfaces of a network adapter of the server;

modifying each originally assigned address by asserting a predetermined bit of the address;

organizing the modified addresses as the address pool of unique addresses for the aggregate; and

assigning a selected modified address from the pool as the unique address for the aggregate.

2. The method of claim 1 wherein each address is a medium access control (MAC) address.

3. The method of claim 2 wherein the predetermined bit is bit 46 of the MAC address.

4. The method of claim 1 wherein the step of collecting comprises the step of collecting addresses from a predetermined data structure associated with each interface.

5. The method of claim 4 wherein the predetermined data structure describes the associated interface.

6. The method of claim 5 wherein contents of the predetermined data structure comprises a type of interface and a medium access control (MAC) address assigned to the interface.

7. The method of claim 1 wherein the step of assigning comprises the step of loading a programmable device and a predetermined data structure associated with each interface with the selected modified address.

8. The method of claim 7 wherein the programmable device is an application specific integrated circuit.

9. The method of claim 1 further comprising the step of returning the selected modified address to the address pool upon destroying the aggregate.

10. A system for implementing a pool containing a plurality of modified addresses adapted for assignment to an aggregate, the system:

a processor;

a network adapter coupled to the processor, the network adapter including physical interfaces connected to links of the aggregate;

an operating system executable by the processor, the operating system comprising a virtual interface process configured to collect addresses originally assigned to the physical interfaces, the virtual interface process modifying each originally assigned address by asserting a predetermined bit of the address; and

a memory coupled to the processor, the memory organized as a pool of modified addresses;

wherein the virtual interface process assigns a selected modified address from the pool as a modified address for the aggregate.

11. Apparatus for implementing a pool containing a plurality of unique addresses adapted for assignment to an aggregate of a server, the apparatus comprising:

means for collecting addresses originally assigned to physical interfaces of a network adapter of the server;

means for modifying each originally assigned address by asserting a predetermined bit of the address;

means for organizing the modified addresses as the address pool of unique addresses for the aggregate; and

means for assigning a selected modified address from the pool as the unique address for the aggregate.

12. The apparatus of claim 11 wherein each address is a medium access control (MAC) address.

13. The apparatus of claim 12 wherein the predetermined bit is bit 46 of the MAC address.

14. The apparatus of claim 11 wherein the means for collecting comprises means for collecting addresses from a predetermined data structure associated with each interface.

15. The apparatus for claim 11 further comprising means for returning the selected modified address to the pool upon destroying the aggregate.

16. A computer readable medium containing executable program instructions for implementing a pool containing a plurality of unique addresses adapted for assignment to an aggregate of a server, the executable program instructions comprising program instructions for:

collecting addresses originally assigned to physical interfaces of a network adapter of the server;

modifying each originally assigned address by asserting a predetermined bit of the address;

organizing the modified addresses as the address pool of unique addresses for the aggregate; and

assigning a selected modified address from the pool as the unique address for the aggregate.

17. The computer readable medium of claim 16 wherein each address is a medium access control (MAC) address.

18. The computer readable medium of claim 17 wherein the predetermined bit is bit 46 of the MAC address.

19. The computer readable medium of claim 16 wherein the program instruction for collecting comprises a program instruction for collecting addresses from a predetermined data structure associated with each interface.

20. The computer readable medium of claim 16 further comprising program instructions for returning the selected modified address to the address pool upon destroying the aggregate.