Arrangement for reducing layer 3 header data supplied to switching logic on a network switch

• US 6,728,246 B1
• Filed: 02/11/2000
• Issued: 04/27/2004
• Est. Priority Date: 12/07/1999
• Status: Expired due to Term

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Kanuri, Mrudula, Egbert, Chandan
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Qureshi, Afsar M.
• Application Number:
  US09/502,570
• Time in Patent Office: 1,537 Days
• Field of Search: 370/352, 370/353, 370/355, 370/389, 370/392, 370/393, 370/465, 370/466, 370/467, 370/469, 370/475, 370/400, 370/422, 709/230, 709/238, 709/240, 709/242
• US Class Current: 370/392
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]
• CPC Class Codes: H04L 49/602 Multilayer or multiprotocol switching, e.g. IP switching

Abstract

A network switch, configured for performing layer 2 and layer 3 switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes network switch ports, each including a port filter configured for obtaining and filtering relevant layer 2 and layer 3 information from a received layer 2 frame. Each port filter, upon filtering the relevant layer 2 and layer 3 information from a received layer 2 frame, outputs the relevant layer 2 and layer 3 information to switching logic, enabling the switching logic to perform layer 3 processing to determine a layer 3 switching operation to be performed on the received layer 2 frame. Hence, the switching logic performs the layer 3 processing based on the relevant layer 2 and layer 3 information, without the necessity of parsing the received layer 2 and layer 3 information by the switching logic.

Claims

1. A method in a network switch the method comprising:

receiving a first layer 2 frame at a network switch port, the first layer 2 frame including layer 3 information;

outputting selected portions of the layer 3 header information from the network switch port, wherein the outputting step includes selecting the portions of the layer 3 header information that are relevant to generation of the layer 3 switching decision; and

generating a layer 3 switching decision in a switching module based on the selected portions of the layer 3 header information.

2. The method of claim 1, wherein the selecting step includes selecting at least an Internet Protocol (IP) source address field and an IP destination address field for the selected portions.

3. The method of claim 2, wherein the selecting step further includes selecting a time to live (TTL) field for the selected portions.

4. The method of claim 2, wherein the outputting step further includes outputting selected portions of layer 2 header information in the first layer 2 frame from the network switch port, the generating step including generating the layer 3 switching decision based on the selected portions of the layer 2 header information.

5. The method of claim 4, wherein the step of outputting selected portions of layer 2 header information includes selecting at least a Media Access Control (MAC) destination address field and MAC source address field for the selected portions of the layer 2 header information.

6. The method of claim 5, wherein the step of outputting selected portions of layer 2 header information further includes selecting a Virtual Local Area Network (VLAN) identifier field for the selected portions of the layer 2 header information.

7. The method of claim 1, wherein the outputting step includes outputting selected portions of layer 2 header information in the first layer 2 frame from the network switch port, the generating step including generating the layer 3 switching decision based on the selected portions of the layer 2 header information.

8. The method of claim 7, wherein the step of outputting selected portions of layer 2 header information includes selecting at least a Media Access Control (MAC) destination address field and MAC source address field for the selected portions of the layer 2 header information.

9. The method of claim 8, wherein the step of outputting selected portions of layer 2 header information further includes selecting a Virtual Local Area Network (VLAN) identifier field for the selected portions of the layer 2 header information.

10. An integrated network switch configured for executing layer 3 switching decisions, the network switch comprising:

a plurality of network switch ports, each network switch port including a port filter configured for obtaining layer 3 information from a received layer 2 frame and outputting portions of the layer 3 information based on a determined relevance of the portions for generation of a layer 3 switching decision; and

a switching module configured for generating the layer 3 switching decision based on the portions of the layer 3 information.

11. The switch of claim 10, wherein the port filter outputs at least an Internet Protocol (IP) source address field and an IP destination address field from the received layer 2 frame for the selected portions.

12. The switch of claim 11, wherein the port filter further outputs a time to live (TTL) field from the received layer 2 frame for the selected portions.

13. The switch of claim 12, wherein the port filter further outputs selected portions of layer 2 header information in the received layer 2 frame, the switching module generating the layer 3 switching decision based on the selected portions of the layer 2 header information.

14. The switch of claim 13, wherein the port filter outputs at least a Media Access Control (MAC) destination address field and a MAC source address field for the selected portions of the layer 2 header information.

15. The switch of claim 14, wherein the port filter further outputs a Virtual Local Area Network (VLAN) identifier field for the selected portions of the layer 2 header information.

16. The switch of claim 10, wherein the port filter further outputs selected portions of layer 2 header information in the received layer 2 frame, the switching module generating the layer 3 switching decision based on the selected portions of the layer 2 header information.

17. The switch of claim 16, wherein the port filter outputs at least a Media Access Control (MAC) destination address field and a MAC source address field for the selected portions of the layer 2 header information.

18. The switch of claim 17, wherein the port filter further outputs a Virtual Local Area Network (VLAN) identifier field for the selected portions of the layer 2 header information.