Layer 2 funnel in fan out network device

• US 6,850,529 B1
• Filed: 10/06/1999
• Issued: 02/01/2005
• Est. Priority Date: 10/06/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wong, Bruce F.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): George, Keith M.
• Application Number:
  US09/414,748
• Time in Patent Office: 1,945 Days
• Field of Search: 370/401, 370/402, 370/407, 370/408, 370/445, 370/446, 370/465, 370/468, 370/466
• US Class Current: 370/401
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00

Abstract

A funnel in fan out network device includes a fast uplink port operating at a first data rate. A plurality of slow ports operate at a second data rate. The second data rate is slower than the first data rate. A processor is configured to direct a packet received on one of the slower ports directly to the fast uplink port without looking up the destination address of the packet.

Claims

1. A funnel in fan out network device comprising:

a fast uplink port operating at a first data rate, wherein the fast uplink port is coupled to a network appliance;

a plurality of slow ports operating at a second data rate, the second data rate being slower than the first data rate;

a memory operable to store addresses, each address associated with a network device reachable via one of the plurality of slower ports; and

a processor configured to direct a first packet received on one of the slower ports directly to the fast uplink port without looking up a destination address of the first packet, and configured to direct a second packet received on the fast uplink port to a particular slow port based on a destination address of the second packet; and

wherein the funnel in fan out network device comprises a port multiplier for the network appliance.

2. A funnel in fan out network device as recited in claim 1, wherein the processor is further configured to store a source address of the first packet in the memory.

3. A funnel in fan out network device as recited in claim 2 wherein the source address is stored in a hash table.

4. A funnel in fan out network device as recited in claim 2 wherein the source address is stored in a binary tree.

5. A funnel in fan out network device as recited in claim 2 wherein the source address comprises a MAC address.

6. A funnel in fan out network device as recited in claim 2 wherein the packet received on one of the slower ports comprises a first packet and wherein the processor is further configured to direct a second packet received on the fast uplink port to a selected slow port from the plurality of slow ports based on a table of addresses stored in the memory, the table indicating that the destination address of the second packet is reachable via the selected slow port.

7. A funnel in fan out network device as recited in claim 1 wherein the funnel in fan out device comprises a layer 2 device.

8. A funnel in fan out network device as recited in claim 1 wherein the destination address of the first packet comprises a MAC address that corresponds to a device connected to one of the slow ports.

9. A funnel in fan out network device as recited in claim 1 wherein the uplink port is designated to receive all packets sent from the slow ports.

10. A funnel in fan out network device as recited in claim 1 wherein the funnel in fan out network device comprises a bridge.

11. A funnel in fan out network device as recited in claim 1 wherein the funnel in fan out network device comprises a switch.

12. A funnel in fan out network device as recited in claim 1 wherein the network appliance comprises a load balancer.

13. A funnel in fan out network device as recited in claim 1 wherein the network appliance comprises a firewall.

14. A funnel in fan out network device as recited in claim 1 wherein the network appliance comprises a packet monitor.

15. A method of directing packets to a network appliance comprising:

receiving a first packet on one of a plurality of slow ports of a port multiplier, the slow ports operating at a first data rate;

transmitting the first packet to a network appliance through a fast uplink port operating at a second data rate, the second data rate being faster than the first data rate, wherein the first packet is transmitted to the network appliance without determining whether a device connected to the fast uplink port corresponds to a packet destination address of the first packet;

receiving a second packet from the network appliance on the fast uplink post; and

transferring the second packet to a slow port that corresponds to a destination address of the second packet.

16. A method of directing packets to a network appliance as recited in claim 15 further including recording a source address of the first packet, and

wherein transferring the second packet comprises transferring the packet to a slow port that has previously sent a packet having a source address that corresponds to the destination address of the second packet.

17. The method of claim 15, further comprising storing a source address and a port indicator, wherein the source address comprises the address of a previous packet received on one of the slower ports and wherein the port identifier identifies the slower port on which the previous packet was received and wherein transferring the second packet comprises transferring the second packet only if the destination address of the second packet corresponds to the source address of a previous packet.

18. The method of claim 17, wherein storing comprises storing using a hash table.

19. The method of claim 17, wherein storing comprises storing using a binary tree.

20. The method of claim 17, wherein the source address further comprises a MAC address.

21. The method of claim 17, wherein transferring the second packet comprises directing a second packet received on the fast uplink port to a selected slow port, the slow port selected using a destination address of the second packet and the hash table.

22. The method of claim 15, wherein receiving a first packet comprises receiving on a layer 2 device.

23. The method of claim 15, wherein the destination address of the second packet comprises a MAC address that corresponds to a device connected to one of the slow ports.

24. The method of claim 15, wherein transmitting the first packet comprises transmitting any packet received on the plurality of slow ports to the network appliance through the fast uplink port.

25. The method of claim 15, wherein receiving a first packet comprises receiving on a bridge.

26. The method of claim 15, wherein receiving a first packet comprises receiving on a switch.

27. The method of claim 15, further comprising serving as a port multiplier for the network appliance.

28. The method of claim 27, wherein the network appliance comprises a load balancer.

29. The method of claim 27, wherein the network appliance comprises a firewall.

30. The method of claim 27, wherein the network appliance comprises a packet monitor.

31. A computer program product for directing packets to a network appliance, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

receiving a first packet on one of a plurality of slow ports of a port multiplier, the slow ports operating at a first data rate;

transmitting the first packet to a network appliance through a fast uplink port operating at a second data rate, the second data rate being faster than the first data rate, wherein the first packet is transmitted to the network appliance without determining whether a device connected to the fast uplink port corresponds to a packet destination address of the first packet;

receiving a second packet on the fast uplink port; and

transferring the second packet to a slow port that corresponds to the packet destination address of the second packet.

32. A computer program product as recited in claim 31 further including instructions for recording a source address of the first packet and

wherein transferring the second packet comprises transferring the packet to a slow port that has previously sent a packet having a source address that corresponds to the destination address of the second packet.

33. The computer program product of claim 32, wherein recording comprises storing using a hash table.

34. The computer program product of claim 32, wherein recording comprises storing using a binary tree.

35. The computer program product of claim 32, wherein the source address further comprises a MAC address.

36. The computer program product of claim 32, wherein transferring the second packet comprises directing a second packet received on the fast uplink port to a selected slow port, the slow port selected using a destination address of the second packet and a port identifier associated with the second packet in memory.

37. The computer program product of claim 31, wherein recording comprises storing the source address of the first packet and a port indicator, wherein the port identifier identifies the slow port on which the first packet was received.

38. The computer program product of claim 31, wherein receiving comprises receiving on a layer 2 device.

39. The computer program product of claim 31, wherein the destination address of the second packet comprises a MAC address that corresponds to a device connected to one of the slow ports.

40. The computer program product of claim 31, wherein transmitting the first packet comprises transmitting any packet received on the plurality of slow ports to the network appliance through the fast uplink port.

41. The computer program product of claim 31, wherein receiving comprises receiving on a bridge.

42. The computer program product of claim 31, wherein receiving comprises receiving on a switch.

43. The computer program product of claim 31, further comprising computer instructions for:

serving as a port multiplier for the network appliance.

44. The computer program product of claim 43, wherein the network appliance comprises a load balancer.

45. The computer program product of claim 43, wherein the network appliance comprises is a firewall.

46. The computer program product of claim 43, wherein the network appliance is a packet monitor.

47. A device for directing packets to a network appliance comprising:

means for receiving a first packet on one of a plurality of slow ports of a port multiplier, the slow ports operating at a first data rate; and

means for transmitting the first packet to a network appliance through a fast uplink port operating at a second data rate, the second data rate being faster than the first data rate, wherein the first packet is transmitted to the network appliance without determining whether a device connected to the fast uplink port corresponds to a packet destination address of the first packet;

means for receiving a second packet from the network appliance on the fast uplink port; and

means for transferring the second packet to a slow port that corresponds to a destination address of the second packet.

48. A funnel in fan out network device comprising:

a port multiplier comprising;

fast uplink port operating at a first data rate; and

a plurality of slow ports operating at a second data rate, the second data rate being slower than the first data rate;

a memory operable to store addresses, each address associated with a network device reachable via one of the plurality of slower ports; and

a processor configured to direct a first packet received on one of the slower ports directly to the fast uplink port without looking up a destination address of the first packet, and configured to direct a second packet received on the fast uplink port to a particular slow port based on a destination address of the second packet; and

wherein the funnel in fan out network device comprises a bridge.

49. A funnel in fan out network device as recited in claim 48, wherein the processor is further configured to store a source address of the first packet in the memory.

50. A funnel in fan out network device as recited in claim 49 wherein the source address is stored in a hash table.

51. A funnel in fan out network device as recited in claim 49 wherein the source address is stored in a binary tree.

52. A funnel in fan out network device as recited in claim 49 wherein the source address comprises a MAC address.

53. A funnel in fan out network device as recited in claim 49 wherein the packet received on one of the slower ports comprises a first packet and wherein the processor is further configured to direct a second packet received on the fast uplink port to a selected slow port from the plurality of slow ports based on a table of addresses stored in the memory, the table indicating that the destination address of the second packet is reachable via the selected slow port.

54. A funnel in fan out network device as recited in claim 48 wherein the destination address of the first packet comprises a MAC address that corresponds to a device connected to one of the slow ports.

55. A funnel in fan out network device as recited in claim 48 wherein the uplink port is designated to receive all packets sent from the slow ports.

56. A method of directing packets to a network appliance comprising:

receiving, at a port multiplier, a first packet on one of a plurality of slow ports operating at a first data rate;

transferring the first packet to a fast uplink port operating at a second data rate, the second data rate being faster than the first data rate, wherein the first packet is transmitted to the fast uplink port without determining whether a device connected to the fast uplink port corresponds to a packet destination address of the first packet;

receiving a second packet on the fast uplink post; and

transferring the second packet to a slow port that corresponds to a destination address of the second packet.

57. The method of claim 56, further comprising recording a source address of the first packet, and

wherein transferring the second packet comprises transferring the packet to a slow port that has previously sent a packet having a source address that corresponds to the destination address of the second packet.

58. The method of claim 56, further comprising storing a source address and a port indicator, wherein the source address comprises the address of a previous packet received on one of the slower ports and wherein the port identifier identifies the slower port on which the previous packet was received and wherein transferring the second packet comprises transferring the second packet only if the destination address of the second packet corresponds to the source address of a previous packet.

59. The method of claim 58, wherein storing comprises storing in a hash table.

60. The method of claim 58, wherein storing comprises storing in a binary tree.

61. The method of claim 58, wherein the source address further comprises a MAC address.

62. The method of claim 58, wherein transferring the second packet comprises directing a second packet received on the fast uplink port to a selected slow port, the slow port selected using a destination address of the second packet and the hash table.

63. The method of claim 56, wherein the destination address of the second packet comprises a MAC address that corresponds to a device connected to one of the slow ports.

64. The method of claim 56, wherein transferring the first packet comprises transferring any packet received on the plurality of slow ports fast uplink port.

65. A computer program product for directing packets to a network appliance, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

receiving, at a port multiplier, a first packet on one of a plurality of slow ports operating at a first data rate;

transferring the first packet to a fast uplink port operating at a second data rate, the second data rate being faster than the first data rate, wherein the first packet is transmitted to the fast uplink port without determining whether a device connected to the fast uplink port corresponds to a packet destination address of the first packet;

receiving a second packet on the fast uplink port; and

transferring the second packet to a slow port that corresponds to the packet destination address of the second packet.

66. The computer program product of claim 65 further comprises instructions for recording a source address of the first packet and

wherein transferring the second packet comprises transferring the packet to a slow port that has previously sent a packet having a source address that corresponds to the destination address of the second packet.

67. The computer program product of claim 66, wherein recording comprises storing using a hash table.

68. The computer program product of claim 66, wherein recording comprises storing using a binary tree.

69. The computer program product of claim 66, wherein the source address further comprises a MAC address.

70. The computer program product of claim 66, wherein transferring the second packet comprises directing a second packet received on the fast uplink port to a selected slow port, the slow port selected using a destination address of the second packet and a port identifier associated with the second packet in memory.

71. The computer program product of claim 66, wherein receiving comprises receiving on a layer 2 device.

72. The computer program product of claim 65, wherein recording comprises storing the source address of the first packet and a port indicator, wherein the port identifier identifies the slow port on which the first packet was received.

73. The computer program product of claim 65, wherein the destination address of the second packet comprises a MAC address that corresponds to a device connected to one of the slow ports.

74. The computer program product of claim 65, wherein transferring the first packet comprises transferring any packet received on the plurality of slow ports to the fast uplink port.