Mirroring of data in a network device

• US 20060114831A1
• Filed: 10/19/2005
• Published: 06/01/2006
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Buduma, Venkateshwar, Wu, Chien-Hsien
• Granted Patent: US 7,738,385 B2
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: H04L 49/208 Port mirroring
• CPC Class Codes: H04L 49/3063 Pipelined operation
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches

Abstract

A network device for processing packets includes an ingress module for performing switching functions on an incoming packet, a memory management unit for storing packets and performing resource checks on each packet and an egress module for performing packet modification and transmitting a modified packet to an appropriate egress port. The egress module is configured to send an unmodified version of the incoming packet to an ingress mirrored-to-port when an ingress port, upon which the incoming packet is received, is configured to mirror packets received by the ingress port.

Claims

1. A network device for processing packets, the network device comprising:

an ingress module for performing switching functions on an incoming packet;

a memory management unit for storing packets and performing resource checks on each packet; and

an egress module for performing packet modification and transmitting a modified packet to an appropriate egress port;

wherein the egress module is configured to send an unmodified version of the incoming packet to an ingress mirrored-to-port when an ingress port, upon which the incoming packet is received, is configured to mirror packets received by the ingress port.

2. The network device according to claim 1, wherein the egress module is further configured to forward a copy of the modified packet to an egress mirrored-to-port, when the appropriate egress port is configured to mirror packets transmitted by the appropriate egress port.

3. The network device according to claim 1, wherein the egress module is configured to perform a lookup of a mirror table to determine the ingress mirrored-to-port.

4. The network device according to claim 3, wherein the ingress mirrored-to-port is obtained from a trunk group identifier.

5. The network device according to claim 3, wherein the egress module is configured to perform lookups of both an ingress mirror index table and an egress mirror index table to determine at least one of the ingress mirrored-to-port and an egress mirrored-to-port.

6. The network device according to claim 1, wherein the egress module is further configured to forward a copy of the modified packet to an address-based mirrored-to-port, when a port having a specific address is configured to mirror packets transmitted by the port.

7. The network device according to claim 1, further comprising a plurality of high speed ports and at least one port for communicating with an external processing unit, wherein the network device interfaces with the external processing unit through a CPU processing module that is connected to the at least port for communicating with the external processing unit.

8. The network device according to claim 1, wherein the egress module is configured to forward the modified packet to a not-unicast mirrored-to-port when the packet is a multicast packet.

9. The network device according to claim 1, wherein the memory management module is configured to replicate the modified or incoming packet based on the number of packets to be forwarded.

10. A method for processing packets in a network device, the method comprises the steps of:

receiving an incoming packet;

storing the incoming packet;

performing resource checks on the incoming packet;

modifying the incoming packet to form a modified packet;

transmitting the modified packet to an appropriate egress port,

sending an unmodified version of the incoming packet to an ingress mirrored-to-port when an ingress port, upon which the incoming packet is received, is configured to mirror packets received by the ingress port.

11. The method according to claim 10, further comprising forwarding a copy of the modified packet to an egress mirrored-to-port, when the appropriate egress port is configured to mirror packets transmitted by the appropriate egress port.

12. The method according to claim 11, wherein the step of forwarding a copy of the modified packet comprises forwarding the modified packet to a not-unicast mirrored-to-port when the modified packet is a multicast packet.

13. The method according to claim 10, further comprising performing a lookup of a mirror table to determine the ingress mirrored-to-port.

14. The method according to claim 12, wherein the ingress mirrored-to-port is obtained from a trunk group identifier.

15. The method according to claim 12, further comprising performing lookups of both an ingress mirror index table and an egress mirror index table to determine at least one of the ingress mirrored-to-port and an egress mirrored-to-port.

16. The method according to claim 10, wherein the step of receiving an incoming packet comprises receiving the incoming packet through a plurality of high speed ports and at least one port for communicating with an external processing unit.

17. The method according to claim 10, wherein the method further comprises replicating the modified or incoming packet based on the number of packets to be forwarded.

18. An apparatus for processing packets in a network device, the apparatus comprising:

receiving means for receiving an incoming packet;

storing means for storing the incoming packet;

checking means for performing resource checks on the incoming packet;

modifying means for modifying the incoming packet to form a modified packet;

transmitting means for transmitting the modified packet to an appropriate egress port,

sending means for sending an unmodified version of the incoming packet to an ingress mirrored-to-port when an ingress port, upon which the incoming packet is received, is configured to mirror packets received by the ingress port.

19. The apparatus according to claim 18, further comprising forwarding means for forwarding a copy of the modified packet to an egress mirrored-to-port, when the appropriate egress port is configured to mirror packets transmitted by the appropriate egress port.

20. The apparatus according to claim 18, further comprising lookup means for performing a lookup of a mirror table to determine the ingress mirrored-to-port.

21. The apparatus according to claim 20, wherein the ingress mirrored-to-port is obtained from a trunk group identifier.

22. The apparatus according to claim 20, the lookup means further comprising means for performing lookups of both an ingress mirror index table and an egress mirror index table to determine at least one of the ingress mirrored-to-port and an egress mirrored-to-port.

23. The apparatus according to claim 18, wherein the receiving means comprises means for receiving the incoming packet through a plurality of high speed ports and at least one port for communicating with an external processing unit.