Translating native medium access control (MAC) addresses to hierarchical MAC addresses and their use

• US 20060098644A1
• Filed: 11/09/2004
• Published: 05/11/2006
• Est. Priority Date: 11/09/2004
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Pullela, Venkateshwar Rao, Kaluve, Shyamasundar
• Granted Patent: US 7,760,720 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04L 61/2596 Translation of addresses of the same type other than IP, e.g. translation from MAC to MAC addresses
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

Different mechanisms are disclosed for translating native Media Access Control (MAC) addresses to and from corresponding hierarchical MAC addresses, and the use of such MAC addresses. A packet switch typically maintains a data structure relating native MAC addresses of certain devices with external MAC addresses, wherein each of the external MAC addresses is typically hierarchical in nature with a portion of the translated address identifying a switch local to the destination device and through which the destination device is to be reached. Other network elements can then readily determine where to route a packet with a destination identified by such a hierarchical MAC address without having to maintain such a large or complete database of MAC addresses as the packet can be routed to the switch based on a portion of the hierarchical address (e.g., typically without regard to the portion of the address identifying the actual destination device).

Claims

1. A method for communicating information through a switch, the method comprising:

maintaining a data structure relating native Media Access Control (MAC) addresses of devices and external MAC addresses, wherein each of said external MAC addresses comprises a hierarchical address including a portion identifying the switch and a second portion identifying a device of which the hierarchical address represents;

receiving a first packet including a first native MAC address as its source address, and in response, translating the first native MAC address to a first external MAC address based on said MAC address information maintained in the data structure and sending a second packet including the first external MAC address as its source address, the second packet being generated based on the contents of the first packet;

receiving a third packet including the first external MAC address as its destination, and in response, translating the first external MAC address to the first native MAC address, and sending a fourth packet including the first native MAC address as its destination address, the fourth packet being generated based on the contents of the third packet.

2. The method of claim 1, wherein said native MAC addresses are flat addresses.

3. The method of claim 1, comprising receiving an authentication request from a first local device associated with the first native MAC address, and in response, authenticating the first local device and updating the data structure, in response to said authentication of the first local device, with the association between the first native MAC address and the first external MAC address.

4. The method of claim 1, wherein the first native MAC address corresponds to a device local to the switch.

5. The method of claim 1, wherein the first packet includes an indication that the first native MAC address is a globally assigned MAC address, and the second packet includes an indication that the first external MAC address is a locally assigned MAC address.

6. The method of claim 1, wherein the first native MAC address includes an indication that it is a globally assigned MAC address, and the first external MAC address includes an indication that it is a locally assigned MAC address.

7. The method of claim 1, wherein the hierarchical address includes one or more network identification portions.

8. A method for communicating information through a switch, the method comprising:

maintaining a data structure relating native Media Access Control (MAC) addresses of devices and external MAC addresses, wherein each of said external MAC addresses comprises a hierarchical address including a portion identifying the switch and a second portion identifying a device of which the hierarchical address represents;

receiving a request packet from a source to identify a destination MAC address based on a higher-level protocol destination address, the request packet including a native MAC address as its source MAC address, and in response, identifying an external address corresponding to the native MAC address based on the data structure and sending a translated request packet based on the request packet to identify the destination MAC address, the translated request packet including the external address as its source MAC address, wherein the external MAC address comprises a hierarchical address including a portion identifying the switch and a second portion identifying a device associated with the native MAC address; and

receiving a reply packet to the translated request packet, the reply packet including the external MAC address, and in response, translating the external MAC address to the native MAC address based on the data structure, and sending a translated reply packet including the native MAC address, the translated reply packet being generated based on the contents of the reply packet.

9. The method of claim 8, wherein the native MAC address is a flat address.

10. The method of claim 8, comprising receiving an authentication request from a first local device associated with the native MAC address, and in response, authenticating the first local device and updating the data structure, in response to said authentication of the first local device, with the association between the native MAC address and the external MAC address.

11. The method of claim 8, wherein the native MAC address corresponds to a device local to the switch.

12. The method of claim 8, wherein the external MAC address includes an indication that it is a locally assigned MAC address, and the native MAC address includes an indication that it is a globally assigned MAC address.

13. The method of claim 8, wherein the request packet includes an indication that the native MAC address is a globally assigned MAC address, and the translated request packet includes an indication that the external MAC address is a locally assigned MAC address.

14. The method of claim 8, wherein the hierarchical address includes one or more network identification portions.

15. One or more computer-readable media containing computer-executable for performing steps for communicating information through a switch, said steps comprising:

maintaining a data structure relating native Media Access Control (MAC) addresses of devices and external MAC addresses, wherein each of said external MAC addresses comprises a hierarchical address including a portion identifying the switch and a second portion identifying a device of which the hierarchical address represents;

receiving a first packet including a first native MAC address as its source address, and in response, translating the first native MAC address to a first external MAC address based on said MAC address information maintained in the data structure and sending a second packet including the first external MAC address as its source address, the second packet being generated based on the contents of the first packet;

receiving a third packet including the first external MAC address as its destination, and in response, translating the first external MAC address to the first native MAC address, and sending a fourth packet including the first native MAC address as its destination address, the fourth packet being generated based on the contents of the third packet.

16. The computer-readable media of claim 15, wherein said native MAC addresses are flat addresses.

17. The computer-readable media of claim 15, comprising receiving an authentication request from a first local device associated with the first native MAC address, and in response, authenticating the first local device and updating the data structure, in response to said authentication of the first local device, with the association between the first native MAC address and the first external MAC address.

18. The computer-readable media of claim 15, wherein the first native MAC address corresponds to a device local to the switch.

19. The computer-readable media of claim 15, wherein the first packet includes an indication that the first native MAC address is a globally assigned MAC address, and the second packet includes an indication that the first external MAC address is a locally assigned MAC address.

20. The computer-readable media of claim 15, wherein the first native MAC address includes an indication that it is a globally assigned MAC address, and the first external MAC address includes an indication that it is a locally assigned MAC address.

21. The computer-readable media of claim 15, wherein the hierarchical address includes one or more network identification portions.

22. An apparatus for switching packets, the apparatus comprising:

means for maintaining a data structure relating native Media Access Control (MAC) addresses of devices and external MAC addresses, wherein each of said external MAC addresses comprises a hierarchical address including a portion identifying the apparatus for switching packets and a second portion identifying a device of which the hierarchical address represents;

means for receiving a request packet from a source to identify a destination MAC address based on a higher-level protocol destination address, the request packet including a native MAC address as its source MAC address, and in response, identifying an external address corresponding to the native MAC address based on the data structure and sending a translated request packet based on the request packet to identify the destination MAC address, the translated request packet including the external address as its source MAC address, wherein the external MAC address comprises a hierarchical address including a portion identifying the apparatus for switching packets and a second portion identifying a device associated with the native MAC address; and

means for receiving a reply packet to the translated request packet, the reply packet including the external MAC address, and in response, translating the external MAC address to the native MAC address based on the data structure, and sending a translated reply packet including the native MAC address, the translated reply packet being generated based on the contents of the reply packet.

23. The apparatus of claim 22, wherein the native MAC address is a flat address.

24. The apparatus of claim 22, comprising means for receiving an authentication request from a first local device associated with the native MAC address, and in response, authenticating the first local device and updating the data structure, in response to said authentication of the first local device, with the association between the native MAC address and the external MAC address.

25. The apparatus of claim 22, wherein the native MAC address corresponds to a device local to the apparatus for switching packets.

26. The apparatus of claim 22, wherein the external MAC address includes an indication that it is a locally assigned MAC address, and the native MAC address includes an indication that it is a globally assigned MAC address.

27. The apparatus of claim 22, wherein the request packet includes an indication that the native MAC address is a globally assigned MAC address, and the translated request packet includes an indication that the external MAC address is a locally assigned MAC address.

28. The apparatus of claim 22, wherein the hierarchical address includes one or more network identification portions.