Multiple address databases in a switch without the need for extra memory

• US 7,995,581 B1
• Filed: 10/23/2007
• Issued: 08/09/2011
• Est. Priority Date: 12/12/2001
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Pannell, Donald
• Primary Examiner(s): Ton; Dang T
• Assistant Examiner(s): Kaur; Pamit
• Application Number:
  US11/975,981
• Time in Patent Office: 1,386 Days
• Field of Search: 370/393
• US Class Current: 370/393
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]

Abstract

A system including N ports, a memory, and a controller. The memory stores M address databases. Each of the M address databases stores MAC addresses and has a database number. A first port of the N ports associated with one of the M address databases receives a frame including a destination MAC address. The controller (i) generates a hashed MAC address based on the destination MAC address and (ii) combines the hashed MAC address and a first database number of the one of the M address databases to generate a bucket address. The bucket address identifies P addresses. Each of the P addresses identifies a location in the memory that stores (i) a MAC address and (ii) a port identifier. N, M, and P are integers greater than one.

Claims

1. A system comprising:

N ports;

a memory configured to store M address databases, each of the M address databases (i) storing MAC addresses and (ii) having a database number, wherein a first port of the N ports associated with one of the M address databases receives a frame including a destination MAC address, wherein N and M are integers greater than one; and

a controller configured to (i) generate a hashed MAC address based on the destination MAC address and (ii) combine the hashed MAC address and a first database number of the one of the M address databases to generate a bucket address,

wherein the bucket address identifies P addresses, and

wherein each of the P addresses identifies a location in the memory that stores (i) a MAC address and (ii) a port identifier, wherein P is an integer greater than one.

2. The system of claim 1, wherein the controller is configured to search the P addresses for an address that matches the destination MAC address.

3. The system of claim 1, wherein the controller is configured to transmit the frame to a selected one of the N ports identified by the port identifier stored in the location having the address matching the destination MAC address.

4. The system of claim 1, wherein the controller is configured to add the hashed MAC address and the first database number of the one of the M address databases to generate the bucket address.

5. The system of claim 1, further comprising N port registers, each of the N port registers associated with a corresponding one of the N ports, wherein the controller is configured to receive a signal identifying (i) a second port of the N ports and (ii) a second database number.

6. The system of claim 5, wherein the controller is configured to store the second database number in one of the N port registers corresponding to the second port of the N ports.

7. The system of claim 6, wherein the controller is configured to transmit frames received at the second port of the N ports according to the second database number stored in the port register for the second port of the N ports.

8. The system of claim 5, wherein the signal includes a control signal received by a network switch from a processor.

9. The system of claim 5, wherein the signal is based on one of a plurality of frames received by the second port of the N ports.

10. A method comprising

transferring data through a switch including (i) memory, (ii) N ports, and (iii) M address databases, each of the M address databases (i) storing MAC addresses and (ii) having a database number, where N and M are integers greater than one;

receiving a frame including a destination MAC address at a first port of the N ports, wherein the first port is associated with a first address database of the M address databases;

hashing the destination MAC address to generate a hashed MAC address; and

combining the hashed MAC address and a first database number of the first address database of the M address databases to generate a bucket address,

wherein the bucket address identifies P addresses identifying a location in the memory storing a MAC address and a port identifier.

11. The method of claim 10, further comprising searching the location for an address matching the destination MAC address.

12. The method of claim 11, further comprising transmitting the frame to a selected one of the N ports identified by the port identifier stored in the location with the address matching the destination MAC address.

13. The method of claim 10, wherein combining comprises adding the hashed MAC address and the first database number of the first address database of the M address databases.

14. The method of claim 10, further comprising receiving a signal identifying (i) a second port of the N ports and (ii) a second database number.

15. The method of claim 14, further comprising associating the second port of the N ports with the second database number.

16. The method of claim 15, further comprising transmitting frames subsequently received at the second port of the N ports according to the association of the second port of the N ports with the second database number.

17. The method of claim 14, wherein the signal includes a control signal received by the switch from a processor.

18. The method of claim 14, wherein the signal includes part of one of a plurality of frames received by the second port of the N ports.