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

• US 7,760,720 B2
• Filed: 11/09/2004
• Issued: 07/20/2010
• 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: Kaluve, Shyamasundar, Pullela, Venkateshwar Rao
• Primary Examiner(s): Pérez-Gutiérrez; Rafael
• Assistant Examiner(s): VIANA DI PRISCO, GERMAN
• Application Number:
  US10/984,305
• Publication Number:
  US 20060098644A1
• Time in Patent Office: 2,079 Days
• Field of Search: 370/389
• 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 request packet from a source to identify a destination MAC address based on a higher-level protocol destination address, with the request packet including;

(1) a native MAC address as;

(a) its source MAC address in the header of the request packet and (b) as a hardware address of the sender of the request packet in the packet data of the request packet, and (2) the higher-level protocol destination address in the packet data of the request packet; 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;

(1) the external address as its source MAC address in the header of the translated request packet, and (2) the external MAC address as the hardware address of the sender in the packet data of the request packet, and (3) the higher-level protocol destination address in the packet data of the request packet;

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;

(1) the external MAC address (a) in the header of the request packet and (b) as a hardware address of the sender of the request packet in the packet data of the reply packet, and (2) the destination MAC address in the packet data of the reply packet, 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 as its destination MAC address in the header of the translated request packet, and packet data including;

(1) the native MAC address as the hardware address of the sender of the request packet, and (2) the destination MAC address, with the translated reply packet being generated based on the contents of the reply packet.

2. The method of claim 1, wherein the native MAC address is a flat address.

3. The method of claim 1, 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.

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

5. The method of claim 1, 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.

6. The method of claim 1, 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.

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

8. 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, with the request packet including;

(1) a native MAC address as;

(a) its source MAC address in the header of the request packet and (b) as a hardware address of the sender of the request packet in the packet data of the request packet, and (2) the higher-level protocol destination address in the packet data of the request packet; 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;

(1) the external address as its source MAC address in the header of the translated request packet, and (2) the external MAC address as the hardware address of the sender in the packet data of the request packet, and (3) the higher-level protocol destination address in the packet data of the request packet;

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

means for receiving a reply packet to the translated request packet, the reply packet including;

(1) the external MAC address (a) in the header of the request packet and (b) as a hardware address of the sender of the request packet in the packet data of the reply packet, and (2) the destination MAC address in the packet data of the reply packet, 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 as its destination MAC address in the header of the translated request packet, and packet data including;

(1) the native MAC address as the hardware address of the sender of the request packet, and (2) the destination MAC address, with the translated reply packet being generated based on the contents of the reply packet.

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

10. The apparatus of claim 8, 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.

11. The apparatus of claim 8, wherein the native MAC address corresponds to a device local to the apparatus for switching packets.

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

15. An apparatus comprising:

one or more interfaces configured for sending and receiving packets;

one or more memories; and

one or more processing elements configured to perform operations, with said operations 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 apparatus and a second portion identifying a device of which the hierarchical address represents;

translating a request packet, received from a source, to a translated request packet for sending out of the apparatus;

wherein the request packet is a request for identifying a destination MAC address based on a higher-level protocol destination address, with the request packet including;

(1) a native MAC address as;

(a) its source MAC address in the header of the request packet and (b) as a hardware address of the sender of the request packet in the packet data of the request packet, and (2) the higher-level protocol destination address in the packet data of the request packet; and

wherein said translating the request packet includes;

identifying an external address corresponding to the native MAC address based on the data structure and creating a translated request packet based on the request packet for identifying the destination MAC address, with the translated request packet including;

(1) the external address as its source MAC address in the header of the translated request packet, and (2) the external MAC address as the hardware address of the sender in the packet data of the request packet, and (3) the higher-level protocol destination address in the packet data of the request packet;

wherein the external MAC address comprises a hierarchical address including a portion identifying the apparatus and a second portion identifying a device associated with the native MAC address; and

translating a reply packet, received in response to the translated request packet, to a translated reply packet for sending out of the apparatus, with the reply packet including;

(1) the external MAC address (a) in the header of the request packet and (b) as a hardware address of the sender of the request packet in the packet data of the reply packet, and (2) the destination MAC address in the packet data of the reply packet;

wherein said translating the reply packet includes translating the external MAC address to the native MAC address based on the data structure; and

wherein the translated reply packet includes;

the native MAC address as its destination MAC address in the header of the translated request packet, and packet data including;

(1) the native MAC address as the hardware address of the sender of the request packet, and (2) the destination MAC address, with the translated reply packet being generated based on the contents of the reply packet.

16. The apparatus of claim 15, wherein the native MAC address is a flat address.

17. The apparatus of claim 15, wherein said operations include:

updating the data structure, in response to authenticating a local device communicatively coupled to the apparatus, with the association between the native MAC address and the external MAC address.

18. The apparatus of claim 15, wherein the native MAC address corresponds to a local device communicatively coupled to the apparatus.

19. The apparatus of claim 15, 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.

20. The apparatus of claim 15, 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.

21. The apparatus of claim 15, wherein the hierarchical address includes one or more network identification portions.

22. One or more tangible computer-readable media encoded thereon with executable instructions for performing operations when said instructions are executed by one or more processing elements of an apparatus, said operations 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 apparatus and a second portion identifying a device of which the hierarchical address represents;

translating a request packet, received from a source, to a translated request packet for sending out of the apparatus;

wherein the request packet is a request for identifying a destination MAC address based on a higher-level protocol destination address, with the request packet including;

(1) a native MAC address as;

(a) its source MAC address in the header of the request packet and (b) as a hardware address of the sender of the request packet in the packet data of the request packet, and (2) the higher-level protocol destination address in the packet data of the request packet; and

wherein said translating the request packet includes;

identifying an external address corresponding to the native MAC address based on the data structure and creating a translated request packet based on the request packet for identifying the destination MAC address, with the translated request packet including;

(1) the external address as its source MAC address in the header of the translated request packet, and (2) the external MAC address as the hardware address of the sender in the packet data of the request packet, and (3) the higher-level protocol destination address in the packet data of the request packet;

wherein the external MAC address comprises a hierarchical address including a portion identifying the apparatus and a second portion identifying a device associated with the native MAC address; and

translating a reply packet, received in response to the translated request packet, to a translated reply packet for sending out of the apparatus, with the reply packet including;

(1) the external MAC address (a) in the header of the request packet and (b) as a hardware address of the sender of the request packet in the packet data of the reply packet, and (2) the destination MAC address in the packet data of the reply packet;

wherein said translating the reply packet includes translating the external MAC address to the native MAC address based on the data structure; and

wherein the translated reply packet includes;

the native MAC address as its destination MAC address in the header of the translated request packet, and packet data including;

(1) the native MAC address as the hardware address of the sender of the request packet, and (2) the destination MAC address, with the translated reply packet being generated based on the contents of the reply packet.

23. The computer-readable media of claim 22, wherein the native MAC address is a flat address.

24. The computer-readable media of claim 22, wherein said operations include:

updating the data structure, in response to authenticating a local device communicatively coupled to the apparatus, with the association between the native MAC address and the external MAC address.

25. The computer-readable media of claim 22, wherein the native MAC address corresponds to a local device communicatively coupled to the apparatus.

26. The computer-readable media 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 computer-readable media 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 computer-readable media of claim 22, wherein the hierarchical address includes one or more network identification portions.