Interface bundles in virtual network devices

• US 20050198371A1
• Filed: 02/19/2004
• Published: 09/08/2005
• Est. Priority Date: 02/19/2004
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wang, Jeffrey YM, Golshan, Ali, Smith, Michael R.
• Granted Patent: US 8,990,430 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/583 Stackable routers
• CPC Class Codes: H04L 45/586 of virtual routers
• CPC Class Codes: H04L 49/1553 Interconnection of ATM switching modules, e.g. ATM switching fabrics
• CPC Class Codes: H04L 49/30 Peripheral units, e.g. input or output ports
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]
• CPC Class Codes: H04L 49/552 by ensuring the integrity of packets received through redundant connections
• CPC Class Codes: H04L 49/70 Virtual switches

Abstract

A virtual network device includes several different virtual network device sub-units, which collectively operate as a single logical network device. An interface bundle includes interfaces in more than one of the different virtual network device sub-units included in the virtual network device. The interface bundle is coupled to a virtual link bundle, which connects the virtual network device to another device. The interface bundle is managed as a single logical interface.

Claims

1. A system comprising:

a virtual link bundle comprising a plurality of communication links, wherein

a first end of each of the communication links is configured to be coupled to a first network device;

a second end of each of a first one of the communication links is configured to be coupled to a first virtual network device sub-unit within a virtual network device; and

a second end of each of a second one of the communication links is configured to be coupled to a second virtual network device sub-unit within the virtual network device.

2. The system of claim 1, further comprising the first network device, wherein

the first network device is configured to select a communication link of the plurality of communication links on which to send a particular packet.

3. The system of claim 2, wherein

each packet sent between the virtual network device and the first network device is sent via only a one of the communication links.

4. The system of claim 2, wherein

the first network device comprises a plurality of ports, each of the ports configured to communicate packets with a respective client,

the first network device is configured to append a header to a packet before sending the packet to the virtual network device via one of the communication links, the header identifies a one of the ports having received the packet.

5. The system of claim 1, further comprising the first virtual network device sub-unit, wherein

the first virtual network device sub-unit is configured to identify whether a one of the communication links is coupled to another virtual network device sub-unit within the virtual network device.

6. The system of claim 1, further comprising the first virtual network device sub-unit and the second virtual network device sub-unit, wherein

the first virtual network device sub-unit and the second virtual network device sub-unit are configured to communicate packets with each other via a virtual network device link.

7. The system of claim 1, wherein

the communication links are configured to be managed as a single link.

8. A system comprising:

a first virtual network device sub-unit comprising;

a first interface; and

a controller coupled to the first interface and configured to forward packets received via the first interface, wherein

the first interface is identified by a first logical identifier,

a second interface is identified by the first logical identifier,

an interface bundle comprises the first interface and the second interface, and

the second interface is comprised in a second virtual network device sub-unit.

9. The system of claim 8, further comprising the second virtual network device sub-unit.

10. The system of claim 9, wherein

the first virtual network device sub-unit is configured to maintain consistent forwarding information with the second virtual network device sub-unit.

11. The system of claim 10, wherein

the controller is configured to perform control protocol processing for the first interface according to a routing protocol running on the interface bundle,

the controller is configured to provide information generated when performing the control protocol processing to a secondary controller comprised in the second virtual network device sub-unit, and

the secondary controller is configured to use the information to manage the second interface.

12. The system of claim 8, wherein

the controller is configured to lookup a destination address of a packet in a lookup table, and

if the lookup table returns the first logical identifier, the first virtual network device sub-unit is configured to prioritize sending the packet via the first interface over sending the packet via the second interface.

13. The system of claim 12, wherein

if the lookup table returns the first logical identifier, the first virtual network device sub-unit is configured to send the packet via the first interface instead of sending the packet via the second interface, unless one or more of the first interface and a link coupled to the first interface are failed.

14. The system of claim 13, wherein

the first virtual network device sub-unit comprises a plurality of interfaces,

more than one of the interfaces are each comprised in the interface bundle, and

the more than one of the interfaces comprises the first interface.

15. The system of claim 14, wherein

if each respective communication link coupled to the more than one of the interfaces fails, the first virtual network device sub-unit is configured to forward the packet via the second interface comprised in the second virtual network device sub-unit.

16. The system of claim 8, wherein

the first virtual network device sub-unit is coupled to the second virtual network device sub-unit by a virtual network device link.

17. The system of claim 16, wherein

the first virtual network device sub-unit is configured to learn that a source address of the second packet is behind the first interface, in response to receiving a second packet via the virtual network device link.

18. The system of claim 16, wherein

the first interface is configured to filter the second packet from a packet flow being sent via the first interface if the second packet was received via the virtual network device link.

19. A system comprising:

a virtual link bundle;

a first virtual network device sub-unit; and

a second virtual network device sub-unit, wherein

a first interface of the first virtual network device sub-unit is coupled to the virtual link bundle,

a second interface of the second virtual network device sub-unit is coupled to the virtual link bundle, and

each of the first interface and the second interface is identified by a first logical identifier.

20. The system of claim 19, further comprising:

a network device coupled to the first virtual network device sub-unit and the second virtual network device sub-unit by the virtual link bundle.

21. The system of claim 20, wherein

the network device is configured to use a hash-based load-sharing algorithm to select one of a plurality of communication links comprised in the virtual link bundle, and

the network device is configured to send a packet via the selected one of the communication links.

22. The system of claim 19, wherein

a primary controller comprised in the first virtual network device sub-unit is configured to perform control protocol processing for the first interface according to a routing protocol running on the virtual link bundle,

the primary controller is configured to send information generated by performing the control protocol processing to a secondary controller comprised in the second virtual network device sub-unit, and

the secondary controller is configured to use the information to manage the second interface.

23. The system of claim 19, wherein

the first virtual network device sub-unit is configured to lookup a destination address of a packet in a lookup table, and

if the lookup table returns the first logical identifier, the first virtual network device sub-unit is configured to prioritize sending the packet via the first interface over sending the packet via the second interface.

24. The system of claim 23, wherein

each of a plurality of interfaces comprised in the first virtual network device sub-unit is coupled to a respective communication link comprised in the virtual link bundle, and

the interfaces comprise the first interface.

25. The system of claim 24, wherein

if each respective communication link coupled to the interfaces fails, the first virtual network device sub-unit is configured to send the packet via the second interface comprised in the second virtual network device sub-unit.

26. The system of claim 23, wherein

the first virtual network device sub-unit is coupled to the second virtual network device sub-unit by a virtual network device link.

27. The system of claim 26, wherein

the first network device is configured to learn that a source address of a packet is behind the first interface, in response to receiving the packet via the virtual network device link.

28. The system of claim 26, wherein

the first interface is configured to filter a second packet from a packet flow being sent via the first interface if the second packet was received via the virtual network device link.

29. A method comprising:

assigning a first logical identifier to each interface included within an interface bundle, wherein

the interface bundle comprises a first interface of a first virtual network device sub-unit and a second interface of second virtual network device sub-unit;

coupling a first end of a first link to the first interface, the first link comprised within a virtual link bundle; and

coupling a first end of second link to the second interface, the second link comprised within the virtual link bundle.

30. The method of claim 29, further comprising:

coupling a second end of the first link to a third network device; and

coupling a second end of the second link to the third network device.

31. The method of claim 30, further comprising:

selecting one of the first link and the second link on which to send a packet from the third network device.

32. The method of claim 31, wherein the selecting is performed using a hash-based algorithm.

33. The method of claim 31, wherein

each packet sent between the third network device and a virtual network device is sent via one, but not both, of the first link and the second link, and

the virtual network device comprises the first virtual network device sub-unit and the second virtual network device sub-unit.

34. The method of claim 33, further comprising:

appending a header to a packet; and

sending the packet and the header from the third network device to the virtual network device via the virtual link bundle, wherein

the third network device comprises a plurality of ports, each of the ports configured to communicate packets with a respective client, and

the header identifies which one of the ports received the packet.

35. The method of claim 29, further comprising:

identifying whether any of the links comprised in the virtual link bundle are anchored to different virtual network device sub-units within the virtual network device.

36. The method of claim 35, wherein the identifying is performed by the first virtual network device sub-unit within the virtual network device.

37. The method of claim 29, further comprising:

communicating packets between the first virtual network device sub-unit and the second virtual network device sub-unit via a virtual network device link.

38. A method comprising:

sending a first packet via a first link of a virtual link bundle if a destination identifier associated with the first packet identifies the virtual link bundle; and

sending a second packet via a second link of the virtual link bundle if a destination identifier associated with the second packet identifies the virtual link bundle, wherein

the first link is coupled to a first virtual network device sub-unit, and

the second link is coupled to a second virtual network device sub-unit.

39. The method of claim 38, further comprising:

selecting the first link from a plurality of links comprised in the virtual link bundle, wherein

the selecting comprises performing a hash-based algorithm.

40. The method of claim 39, further comprising:

appending a header to the first packet, wherein

the header identifies which port of a plurality of ports received the first packet, and

the sending the first packet via the first link comprises sending the header via the first link.

41. A method comprising:

receiving a packet, wherein

a destination identifier for the packet identifies an interface bundle, and the interface bundle comprises a first interface; and

filtering the packet from a packet flow being sent via the first interface if the packet was received via a virtual network device link.

42. The method of claim 41, further comprising:

sending the packet via the first interface if the packet was not received via the virtual network device link.

43. The method of claim 42, further comprising:

maintaining consistency between a lookup table comprised in a first virtual network device sub-unit and a second lookup table comprised in a second virtual network device sub-unit.

44. The method of claim 42, further comprising

performing control protocol processing for the interface bundle at a primary controller comprised in a first virtual network device sub-unit, wherein

the first interface is comprised in the first virtual network device sub-unit.

45. The method of claim 44, further comprising:

managing a second interface of the second virtual network device sub-unit in response to information generated by the performing the control protocol processing, wherein

the second interface is comprised in the interface bundle.

46. The method of claim 45, further comprising:

looking up a destination address of a second packet in a lookup table, and

if the lookup table returns the destination identifier, sending the sending packet via the first interface of the first virtual network device sub-unit instead of sending the packet via the second interface of the second virtual network device sub-unit.

47. The method of claim 41, further comprising:

learning that a source address of the packet is behind a local interface, in response to receiving the packet via the virtual network device link.

48. A system comprising:

means for sending a first packet via a first link of a virtual link bundle if a destination identifier associated with the first packet identifies the virtual link bundle; and

means for sending a second packet via a second link of the virtual link bundle if a destination identifier associated with the second packet identifies the virtual link bundle, wherein

the first link is coupled to a first virtual network device sub-unit, and

the second link is coupled to a second virtual network device sub-unit.

49. The system of claim 48, further comprising:

means for selecting the first link from a plurality of links comprised in the virtual link bundle, wherein

the selecting comprises performing a hash-based algorithm.

50. The system of claim 49, further comprising:

means for appending a header to the first packet, wherein

the header identifies which port of a plurality of ports received the first packet, and

the sending the first packet via the first link comprises sending the header via the first link.

51. A system comprising:

means for receiving a packet, wherein

a destination identifier for the packet identifies an interface bundle, and

the interface bundle comprises a first interface; and

means for filtering the packet from a packet flow being sent via the first interface if the packet was received via a virtual network device link.

52. The system of claim 51, further comprising:

means for sending the packet via the first interface if the packet was not received via the virtual network device link.

53. The system of claim 52, further comprising:

means for maintaining consistency between a lookup table comprised in a first virtual network device sub-unit and a second lookup table comprised in a second virtual network device sub-unit.

54. The system of claim 52, further comprising

means for performing control protocol processing for the interface bundle at a primary controller comprised in a first virtual network device sub-unit, wherein

the first interface is comprised in the first virtual network device sub-unit.

55. The system of claim 54, further comprising:

means for managing a second interface of the second virtual network device sub-unit in response to information generated by the performing the control protocol processing, wherein

the second interface is comprised in the interface bundle.

56. The system of claim 55, further comprising:

means for looking up a destination address of a second packet in a lookup table, and

means for sending the sending packet via the first interface of the first virtual network device sub-unit instead of sending the packet via the second interface of the second virtual network device sub-unit if the lookup table returns the destination identifier.

57. The system of claim 51, further comprising:

means for learning that a source address of the packet is behind a local interface, in response to receiving the packet via the virtual network device link.

58. A computer readable medium comprising program instructions executable to:

send a first packet via a first link of a virtual link bundle if a destination identifier associated with the first packet identifies the virtual link bundle; and

send a second packet via a second link of the virtual link bundle if a destination identifier associated with the second packet identifies the virtual link bundle, wherein

the first link is coupled to a first virtual network device sub-unit, and

the second link is coupled to a second virtual network device sub-unit.

59. The computer readable medium of claim 58, wherein the program instructions are further executable to:

select the first link from a plurality of links comprised in the virtual link bundle, wherein

selecting the first link from the plurality of links comprises performing a hash-based algorithm.

60. The computer readable medium of claim 59, wherein the program instructions are further executable to:

append a header to the first packet, wherein

the header identifies which port of a plurality of ports received the first packet, and

sending the first packet via the first link comprises sending the header via the first link.

61. A computer readable medium comprising program instructions executable to:

detect reception of a packet, wherein

a destination identifier for the packet identifies an interface bundle, and

the interface bundle comprises a first interface; and

filter the packet from a packet flow being sent via the first interface if the packet was received via a virtual network device link.

62. The computer readable medium of claim 61, wherein the program instructions are further executable to:

send the packet via the first interface if the packet was not received via the virtual network device link.

63. The computer readable medium of claim 62, wherein the program instructions are further executable to:

maintain consistency between a lookup table comprised in a first virtual network device sub-unit and a second lookup table comprised in a second virtual network device sub-unit.

64. The computer readable medium of claim 62, wherein the program instructions are further executable to:

perform control protocol processing for the interface bundle at a primary controller comprised in a first virtual network device sub-unit, wherein

the first interface is comprised in the first virtual network device sub-unit.

65. The computer readable medium of claim 64, wherein the program instructions are further executable to:

manage a second interface of the second virtual network device sub-unit in response to information generated by performing the control protocol processing, wherein

the second interface is comprised in the interface bundle.

66. The computer readable medium of claim 65, wherein the program instructions are further executable to:

look up a destination address of a second packet in a lookup table, and

if the lookup table returns the destination identifier, send the sending packet via the first interface of the first virtual network device sub-unit instead of sending the packet via the second interface of the second virtual network device sub-unit.

67. The computer readable medium of claim 61, wherein the program instructions are further executable to:

learn that a source address of the packet is behind a local interface, in response to detecting reception of the packet via the virtual network device link.