Switch port analyzers

• US 7,474,666 B2
• Filed: 09/03/2003
• Issued: 01/06/2009
• Est. Priority Date: 09/03/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Cressa, Matthew, Kloth, Raymond J., Edsall, Thomas James, Ghosh, Kalyan K., Dutt, Dinesh Ganapathy, Rastogi, Gaurav
• Primary Examiner(s): Ho; Duc C
• Application Number:
  US10/655,452
• Publication Number:
  US 20050053073A1
• Time in Patent Office: 1,952 Days
• Field of Search: 370/235, 370/392, 370/401, 370/241
• US Class Current: 370/401
• CPC Class Codes: H04L 2212/00 Encapsulation of packets
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/18 Protocol analysers
• CPC Class Codes: H04L 49/357 Fibre channel switches
• CPC Class Codes: H04L 49/555 Error detection

Abstract

Methods and devices are provided for non-disruptive monitoring of network traffic through one or more ports of a Fibre Channel network device. Preferred embodiments of the invention are used in conjunction with the switched port analyzer (“SPAN”) and/or remote SPAN (“RSPAN”) features. SPAN mode operation allows traffic through any Fibre Channel interface of a network device to be replicated and delivered to a single port on the same network device. Ingress SPAN allows the monitoring of some or all packets that ingress a specified port or ports. Egress SPAN allows the monitoring of some or all packets that egress a specified port or ports. RSPAN allows the delivery of the replicated traffic to a port on a remote network device. Filtering may be applied, for example, to SPAN packets having selected virtual storage area network numbers.

Claims

1. A network device, comprising:

an ingress port;

at least one buffer associated with the ingress port;

at least one egress port; and

at least one processor configured to do the following;

receive a first Fibre Channel packet from ingress port;

determining that a header of the first Fibre Channel packet indicates that the first Fibre Channel packet should be transmitted to a first egress port;

store a copy of the first Fibre Channel packet in a buffer associated with the ingress port;

transmit a first replica of the first Fibre Channel packet to the first egress port; and

transmit a second replica of the first Fibre Channel packet to a second egress port, the second egress port is not configured to participate in the buffer-to-buffer credit flow control mechanism of the Fibre Channel protocol, wherein the second egress port is not configured to act as an ingress port.

2. The network device of claim 1, wherein the second egress port is a port of the network device.

3. The network device of claim 1, wherein the second egress port is a port of another network device.

4. The network device of claim 1, wherein the network device is configured to transmit the second replica of the first Fibre Channel packet to the second egress port regardless of the identity of the first egress port.

5. The network device of claim 1, further configured to do the following:

receive a second Fibre Channel packet at the ingress port, a header of the second Fibre Channel packet indicating that the second Fibre Channel packet should be transmitted to a third egress port;

store a copy of the second Fibre Channel packet in a buffer associated with the ingress port;

transmit a first replica of the second Fibre Channel packet to the third egress port; and

transmit a second replica of the second Fibre Channel packet to the second egress port.

6. A method for use in a Fibre Channel network, the method comprising:

receiving a first Fibre Channel packet, a header of the first Fibre Channel packet indicating that the first Fibre Channel packet should be transmitted to a first egress port;

storing a copy of the first Fibre Channel packet;

transmitting a first replica of the first Fibre Channel packet to the first egress port; and

transmitting a second replica of the first Fibre Channel packet to a second egress port, the second egress port is not configured to participate in the buffer-to-buffer credit flow control mechanism of the Fibre Channel protocol, wherein the second egress port is not configured to act as an ingress port.

7. The method of claim 6, wherein the second egress port is a port of the network device.

8. The method of claim 6, wherein the second egress port is a port of another network device.

9. The method of claim 6, wherein the second replica of the first Fibre Channel packet is transmitted to the second egress port regardless of the identity of the first egress port.

10. The method of claim 6, further comprising:

receiving a second Fibre Channel packet, a header of the second Fibre Channel packet indicating that the second Fibre Channel packet should be transmitted to a third egress port;

storing a copy of the second Fibre Channel packet;

transmitting a first replica of the second Fibre Channel packet to the third egress port; and

transmit a second replica of the second Fibre Channel packet to the second egress port.

11. A computer readable medium encoded with a computer program, the computer program comprising instructions for controlling a network device to perform the following steps:

receiving a first Fibre Channel packet at an ingress port of the network device, a header of the first Fibre Channel packet indicating that the first Fibre Channel packet should be transmitted to a first egress port of the network device;

storing a copy of the first Fibre Channel packet in a buffer associated with the ingress port;

transmitting a first replica of the first Fibre Channel packet to the first egress port; and

transmitting a second replica of the first Fibre Channel packet to a second egress port, the second egress port is not configured to participate in the buffer-to-buffer credit flow control mechanism of the Fibre Channel protocol , wherein the second egress port is not configured to act as an ingress port.

12. The computer readable medium of claim 11, wherein the second egress port is a port of the network device.

13. The computer readable medium of claim 11, wherein the second egress port is a port of another network device.

14. A method for use in a Fibre Channel network, the method comprising:

receiving a Fibre Channel packet;

determining, based on a header of the Fibre Channel packet, that the Fibre Channel packet should be transmitted to a first egress port and that the Fibre Channel packet has been assigned a virtual storage area network number;

storing a copy of the Fibre Channel packet;

transmitting a first replica of the Fibre Channel packet to the first egress port; and

determining, based at least in part on the virtual storage area network number, whether to transmit a second replica of the Fibre Channel packet to a second egress port.

15. The method of claim 14, wherein the second egress port is a port of the network device.

16. The method of claim 14, wherein the second egress port is a port of another network device.

17. A computer readable medium encoded with a computer program, the computer program comprising instructions for controlling a network device to perform the following steps:

receive a Fibre Channel packet at an ingress port;

determine, based on a header of the Fibre Channel packet, that the Fibre Channel packet should be transmitted to a first egress port and that the Fibre Channel packet has been assigned a virtual storage area network number;

store a copy of the Fibre Channel packet in a buffer associated with the ingress port;

transmit a first replica of the Fibre Channel packet to the first egress port; and

determine, based at least in part on the virtual storage area network number, whether to transmit a second replica of the Fibre Channel packet to a second egress port.

18. The computer readable medium of claim 17, wherein the second egress port is a port of the network device.

19. The computer readable medium of claim 17, wherein the second egress port is a port of another network device.

20. A network device, comprising:

an ingress port;

at least one buffer associated with the ingress port;

at least one egress port; and

at least one processor configured to do the following;

receive a Fibre Channel packet at the ingress port;

determine that the Fibre Channel packet should be transmitted to a first egress port;

store a copy of the Fibre Channel packet in a buffer associated with the ingress port;

transmit a first replica of the Fibre Channel packet to the first egress port; and

apply a rule to determine whether to rewrite, drop, decrypt or truncate a second replica of the Fibre Channel packet that is transmitted to a second egress port, wherein the second egress port is not configured to act as an ingress port.

21. The network device of claim 20, wherein the rule involves the ingress port.

22. The network device of claim 20, wherein the rule involves the first egress port.

23. The network device of claim 20, further configured to obtain a virtual storage area network number from the Fibre Channel packet and wherein the rule involves the virtual storage area network number.

24. The network device of claim 20, wherein the modifying of the second replica comprises dropping the second replica.

25. A method for use in a Fibre Channel network, the method comprising:

receiving a Fibre Channel packet;

determining that the Fibre Channel packet should be transmitted to a first egress port;

storing a copy of the Fibre Channel packet;

transmitting a first replica of the Fibre Channel packet to the first egress port; and

applying a rule to determine whether to rewrite, drop, decrypt or truncate a second replica of the Fibre Channel packet that is transmitted to a second egress port, wherein the second egress port is not configured to act as an ingress port.

26. The method of claim 25, wherein the rule involves the ingress port.

27. The method of claim 25, wherein the rule involves the first egress port.

28. The method of claim 25, further comprising obtaining a virtual storage area network number from the Fibre Channel packet and wherein the rule involves the virtual storage area network number.

29. A computer readable medium encoded with a computer program, the computer program comprising instructions for controlling a network device to perform the following steps:

receive a Fibre Channel packet at an ingress port;

determine that the Fibre Channel packet should be transmitted to a first egress port;

store a copy of the Fibre Channel packet in a buffer associated with the ingress port;

transmit a first replica of the Fibre Channel packet to the first egress port; and

apply a rule to determine whether to rewrite, drop, decrypt or truncate a second replica of the Fibre Channel packet that is transmitted to a second egress port, wherein the second egress port is not configured to act as an ingress port.

30. The computer readable medium of claim 29, wherein the rule involves the ingress port.

31. The computer readable medium of claim 29, wherein the rule involves the first egress port.

32. The computer readable medium of claim 29, further comprising instructions for controlling the network device to obtain a virtual storage area network number from the Fibre Channel packet and wherein the rule involves the virtual storage area network number.

33. A computer readable medium encoded with a computer program, the computer program comprising instructions for controlling a port of a network device for use in a Fibre Channel protocol network to perform the following steps:

ignore the buffer-to-buffer credit flow control mechanism of the Fibre Channel protocol for data traffic received at an egress port; and

allow the data traffic to be sent only in the egress port'"'"'s egress direction.

34. The computer readable medium of claim 33, further comprising instructions for controlling the port to receive frames from within the network device.

35. The computer readable medium of claim 33, further comprising instructions for controlling the port to output frames with an extended inter-switch link header.

36. The computer readable medium of claim 33, further comprising instructions for controlling the port to output frames without an extended inter-switch link header.

37. A method for controlling a port of a network device for use in a Fibre Channel protocol network, the method comprising:

ignoring the buffer-to-buffer credit flow control mechanism of the Fibre Channel protocol for data traffic received at an egress port; and

allowing the data traffic to be sent only in the egress port'"'"'s egress direction.

38. The method of claim 37, further comprising controlling the port to receive frames from within the network device.

39. The method of claim 37, further comprising controlling the port to output frames with an extended inter-switch link header.

40. The method of claim 37, further comprising controlling the port to output frames without an extended inter-switch link header.

41. A network device for use in a Fibre Channel network, the network device comprising:

an ingress port configured to receive a Fibre Channel packet, a header of the Fibre Channel packet indicating that the Fibre Channel packet should be transmitted to a first egress port, wherein the ingress port is further configured to;

store a copy of the Fibre Channel packet in a buffer associated with the ingress port;

transmit a first replica of the Fibre Channel packet to the first egress port; and

transmit a second replica of the Fibre Channel packet;

a reflector port configured to;

receive the second replica of the Fibre Channel packet;

encapsulate the second replica of the Fibre Channel packet with routing information such that the Fibre Channel packet can traverse an intervening network to a second network device; and

transmit the encapsulated second replica of the Fibre Channel packet to a second egress port of the second network device, the second egress port is not configured to participate in the buffer-to-buffer credit flow control mechanism of the Fibre Channel protocol, wherein the second egress port is not configured to act as an ingress port.

42. The network device of claim 41, wherein the reflector port does not make a third replica of the Fibre Channel packet.

43. The network device of claim 41, wherein the reflector port makes a determination not to make a third replica of the Fibre Channel packet based on internal header information of the second replica of the Fibre Channel packet.

44. An apparatus, comprising:

means for receiving a first Fibre Channel packet, a header of the first Fibre Channel packet indicating that the first Fibre Channel packet should be transmitted to a first egress port;

means for storing a copy of the first Fibre Channel packet;

means for transmitting a first replica of the first Fibre Channel packet to the first egress port; and

means for transmitting a second replica of the first Fibre Channel packet to a second egress port, the second egress port is not configured to participate in the buffer-to-buffer credit flow control mechanism of the Fibre Channel protocol, wherein the second egress port is not configured to act as an ingress port.

45. An apparatus, comprising:

means for receiving a Fibre Channel packet;

means for determining, based on a header of the Fibre Channel packet, that the Fibre Channel packet should be transmitted to a first egress port and that the Fibre Channel packet has been assigned a virtual storage area network number;

means for storing a copy of the Fibre Channel packet;

means for transmitting a first replica of the Fibre Channel packet to the first egress port; and

means for determining, based at least in part on the virtual storage area network number, whether to transmit a second replica of the Fibre Channel packet to a second egress port.

46. The apparatus of claim 45, wherein the second egress port is a port of the network device.

47. The apparatus of claim 45, wherein the second egress port is a port of another network device.