Method and system for automatic configuration of network links to attached devices

• US 6,128,729 A
• Filed: 12/16/1997
• Issued: 10/03/2000
• Est. Priority Date: 12/16/1997
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Faulk, Robert L. Jr., McGuire, Robert M., Kimball, Karen E.
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): OMAR, OMAR B
• Application Number:
  US08/991,943
• Time in Patent Office: 1,022 Days
• Field of Search: 370/16.1, 370/85.13, 370/54, 370/255, 364/471.03, 709/200, 709/220, 709/238, 709/239, 713/1, 713/2, 713/100, 708/200
• US Class Current: 713/1
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 41/046 comprising network management agents or mobile agents therefor
• CPC Class Codes: H04L 41/0836 to enhance reliability, e.g. reduce downtime
• CPC Class Codes: H04L 41/0886 Fully automatic configuration

Abstract

An intelligent network agent software application for multi-segment network devices (such as bridges or multi-segment repeaters) which have one or more network links automatically configures the network links. Several automatic configuration and loop-recovery features are encompassed, each of which applies toward intelligently making decisions on the user'"'"'s behalf, without special knowledge or intervention on the part of the user. Such configuration includes: assigning bridged links to different segments (to maximize the connectivity offered by the bridging and to prevent looping); setting up bridged links on a bridge to form full connectivity across the network with another bridge; setting up redundant connections; disabling ports which are causing loops in the network, or other configuration actions. The agent is preferably fully embedded in the hardware device. However, the agent can also exist remotely and communicate with other software intelligence embedded in the hardware device via either an in-band (network) or an out-of-band (non-network) hardware connection.

Claims

1. A method by which a multi-segment network device configures network device connections to a first link, the method comprising the following step:

(a) if the multi-segment network device detects that a first bridging device is attached to the first link and that no repeating device is attached to the first link, performing the following substep;

(a.1) if the first bridging device has been designated as a preferred bridging device, performing the following substeps;

adding the first link to a segment, if available, that does not include a link to the first bridging device and

if there is no segment available that does not include a link to the first bridging device, disabling the first link.

2. A method as in claim 1 wherein step (a) additionally includes the following substep:

(a.2) if the first bridging device has not been designated as the preferred bridging device, performing the following substeps;

if no other links to the first bridging device have been configured, adding the first link to any supported segment, and

if another link to the first bridging device has already been configured, disabling the first link.

3. A method as in claim 1 additionally comprising the following substep:

(b) if the multi-segment network device detects that a first repeating device is attached to the first link, performing the following substep;

(b.1) if another link to the first repeating device has already been configured, disabling the first link.

4. A method as in claim 3 wherein step (b) additionally includes the following substep:

(b.2) if another link to the first repeating device has not already been configured and the preferred bridging device is also attached to the first link, performing the following substeps;

adding the first link to a segment, if available, that does not include a link to the preferred bridging device, and

if there is no segment available that does not include a link to the preferred bridging device, disabling the first link.

5. A method as in claim 4 wherein step (b) additionally includes the following substep:

(b.3) if another link to the first repeating device has not already been configured and a bridging device which is not the preferred bridging device is attached to the first link, performing the following substep;

adding the first link to any supported segment.

6. A method by which a multi-segment network device configures network device connections to a first link, the method comprising the following step:

(a) if the network device detects that a first repeating device is attached to the first link, performing the following substeps;

(a.1) if another link to the first repeating device has already been configured, disabling the first link

(a.2) if another link to the first repeating device has not already been configured and a preferred bridging device is also attached to the first link, performing the following substeps;

adding the first link to a segment, if available, that does not include a link to the preferred bridging device, and

if there is no segment available that does not include a link to the preferred bridging device, disabling the first link.

7. A method as in claim 6 wherein step (a) additionally includes the following substep:

(a.3) if another link to the first repeating device has not already been configured and a bridging device which is not the preferred bridging device is attached to the first link, performing the following substep;

adding the first link to any supported segment.

8. A multi-segment network device comprising:

a plurality of segments;

a plurality of links;

an agent used to configure network device connections to the plurality of links, the agent adding the first link to a segment, if available, that does not include a link to the preferred bridging device when the multi-segment network device detects that a first bridging device is attached to the first link, that no repeating device is attached to the first link and that the first bridging device has been designated as a preferred bridging device, the agent disabling the first link when the first bridging device is attached to the first link, no repeating device is attached to the first link, the first bridging device has been designated as the preferred bridging device and there is available no segment that does not include a link to the first bridging device.

9. A multi-segment network device as in claim 8 wherein the agent adds the first link to any supported segment when the multi-segment network device detects that a first bridging device is attached to the first link, that no repeating device is attached to the first link, that the first bridging device has not been designated as the preferred bridging device, and that no other links to the first bridging device have been configured, and the agent disables the first link when the multi-segment network device detects that a first bridging device is attached to the first link, that no repeating device is attached to the first link, that the first bridging device has not been designated as the preferred bridging device, and that another link to the first bridging device has already been configured.

10. A multi-segment network device as in claim 8, wherein the agent disables the first link when the multi-segment network device detects a first repeating device is attached to the first link and that another link to the first repeating device has already been configured, disabling the first link.

11. A multi-segment network device as in claim 10, wherein the agent adds the first link to a segment, if available, that does not include a link to the preferred bridging device when the multi-segment network device detects a first repeating device is attached to the first link, that another link to the first repeating device has not already been configured and that the preferred bridging device is also attached to the first link, and the agent disables the first link when the multi-segment network device detects a first repeating device is attached to the first link, that another link to the first repeating device has not already been configured, that the preferred bridging device is also attached to the first link, and that there is no available segment that does not include a link to the preferred bridging device.

12. A multi-segment network device as in claim 11 wherein the agent adds the first link to any supported segment step when the multi-segment network device detects the first repeating device is attached to the first link, that another link to the first repeating device has not already been configured, and that a bridging device which is not the preferred bridging device is attached to the first link.

13. A multi-segment network device comprising:

a plurality of segments;

a plurality of links;

an agent used to configure network device connections to the plurality of links, the agent adding the first link to a segment, if available, that does not include a link to the preferred bridging device when the multi-segment network device detects a first repeating device is attached to the first link, that another link to the first repeating device has not already been configured and that the preferred bridging device is also attached to the first link, and the agent disabling the first link when the multi-segment network device detects a first repeating device is attached to the first link, that another link to the first repeating device has not already been configured, that the preferred bridging device is also attached to the first link, and that there is no available segment that does not include a link to the preferred bridging device.

14. A multi-segment network device as in claim 13 wherein the agent adds the first link to any supported segment step when the multi-segment network device detects the first repeating device is attached to the first link, that another link to the first repeating device has not already been configured, and that a bridging device which is not the preferred bridging device is attached to the first link.

15. A method by which a multi-segment network device configures network device connections to a first link, the method comprising the following step:

(a) if the multi-segment network device detects that a first bridging device is attached to the first link and that no repeating device is attached to the first link, performing the following substep;

(a.1) if the first bridging device has been designated as a preferred bridging device, performing the following substeps;

adding the first link to a segment, if available, that does not include a link to the first bridging device and

if there is no segment available that does not include a link to the first bridging device, making the first link a redundant connection.

16. A method as in claim 15 wherein step (a) additionally includes the following substep:

(a.2) if the first bridging device has not been designated as the preferred bridging device, performing the following substeps;

if no other links to the first bridging device have been configured, adding the first link to any supported segment, and

if another link to the first bridging device has already been configured, making the first link a redundant connection.

17. A method as in claim 16 additionally comprising the following substep:

(b) if the multi-segment network device detects that a first repeating device is attached to the first link, performing the following substep;

(b.1) if another link to the first repeating device has already been configured, making the first link a redundant connection.

18. A method as in claim 17 wherein step (b) additionally includes the following substep:

(b.2) if another link to the first repeating device has not already been configured and the preferred bridging device is also attached to the first link, performing the following substeps;

adding the first link to a segment, if available, that does not include a link to the preferred bridging device, and

if there is no segment available that does not include a link to the preferred bridging device, making the first link a redundant connection.

19. A method by which a multi-segment network device configures network device connections to a first link, the method comprising the following step:

(a) if the network device detects that a first repeating device is attached to the first link, performing the following substeps;

(a.1) if another link to the first repeating device has already been configured, making the first link a redundant connection

(a.2) if another link to the first repeating device has not already been configured and a preferred bridging device is also attached to the first link, performing the following substeps;

adding the first link to a segment, if available, that does not include a link to the preferred bridging device, and

if there is no segment available that does not include a link to the preferred bridging device, making the first link a redundant connection.

20. A multi-segment network device comprising:

a plurality of segments;

a plurality of links;

an agent used to configure network device connections to the plurality of links, the agent adding the first link to a segment, if available, that does not include a link to the preferred bridging device when the multi-segment network device detects that a first bridging device is attached to the first link, that no repeating device is attached to the first link and that the first bridging device has been designated as a preferred bridging device, the agent making the first link a redundant connection when the first bridging device is attached to the first link, no repeating device is attached to the first link, the first bridging device has been designated as the preferred bridging device and there is available no segment that does not include a link to the first bridging device.

21. A multi-segment network device as in claim 20, wherein the agent disables the first link when the multi-segment network device detects a first repeating device is attached to the first link and that another link to the first repeating device has already been configured, making the first link a redundant connection.

22. A multi-segment network device as in claim 21, wherein the agent adds the first link to a segment, if available, that does not include a link to the preferred bridging device when the multi-segment network device detects a first repeating device is attached to the first link, that another link to the first repeating device has not already been configured and that the preferred bridging device is also attached to the first link, and the agent disables the first link when the multi-segment network device detects a first repeating device is attached to the first link, that another link to the first repeating device has not already been configured, that the preferred bridging device is also attached to the first link, and that there is no available segment that does not include a link to the preferred bridging device.

23. A multi-segment network device as in claim 22 wherein the agent adds the first link to any supported segment step when the multi-segment network device detects the first repeating device is attached to the first link, that another link to the first repeating device has not already been configured, and that a bridging device which is not the preferred bridging device is attached to the first link.

24. A multi-segment network device comprising:

a plurality of segments;

a plurality of links;

an agent used to configure network device connections to the plurality of links, the agent adding the first link to a segment, if available, that does not include a link to the preferred bridging device when the multi-segment network device detects a first repeating device is attached to the first link, that another link to the first repeating device has not already been configured and that the preferred bridging device is also attached to the first link, and the agent making the first link a redundant connection when the multi-segment network device detects a first repeating device is attached to the first link, that another link to the first repeating device has not already been configured, that the preferred bridging device is also attached to the first link, and that there is no available segment that does not include a link to the preferred bridging device.

25. A method by which a multi-segment network device configures network device connections to a first link, the method comprising the following step:

(a) if the network device detects that a first repeating device is attached to the first link, performing the following substeps;

(a.1) if another link to the first repeating device has already been configured, disabling the first link.

26. A multi-segment network device comprising:

a plurality of segments;

a plurality of links; and

,

an agent used to configure the plurality of links, the agent obtaining information about devices connected to links in the plurality of links, and based on the information, the agent configuring each link by performing one of the following actions for each link;

disabling the link, and

assigning the link to one of the plurality of segments;

wherein in configuring links, the agent does not allow two links connected to a same external bridging device to be assigned to a same segment from the plurality of segments.

27. A multi-segment network device as in claim 26, wherein in configuring links, when more than one link from the plurality of links are connected to a first bridging device, a maximum number of links connected to the first bridging device are enabled with the following constraints:

no looping is caused, and

no two links connected to the first bridging device are assigned to a same segment from the plurality of segments.

28. A multi-segment network device as in claim 26 wherein the agent is embedded within hardware that is in a same housing that houses hardware implementing the plurality of segments.

29. A multi-segment network device as in claim 26 wherein the agent is embedded within hardware that is external to housing that houses hardware implementing the plurality of segments.

30. A multi-segment network device as in claim 26 wherein the multi-segment network device is one of the following:

a network bridge;

a switch;

a router;

a repeater; and

a multi-segment repeater.

31. A multi-segment network device as in claim 26 wherein the information about the devices connected to the links in the plurality of links is detected by the agent.

32. A multi-segment network device as in claim 26 wherein the information about the devices connected to the links in the plurality of links is furnished by an application that is external to the agent.

33. A multi-segment network device as in claim 26 wherein the information about the devices connected to the links in the plurality of links is supplied by a user of the multi-segment network device.

34. A method by which an agent configures a plurality of links within a multi-segment network device, the method comprising the following steps:

(a) obtaining, by the agent, information about devices connected to links in the plurality of links; and

,

(b) based on the information, configuring, by the agent, each link, including one and only one of the following substeps being performed for each link;

(b.1) disabling the link, and

(b.2) assigning the link to one of a plurality of segments;

wherein in configuring links, the agent does not allow two links connected to a same external bridging device to be assigned to a same segment from the plurality of segments.

35. A method as in claim 34, wherein in step (b) the agent configures link so that when more than one link from the plurality of links are connected to a first bridging device, a maximum number of links connected to the first bridging device are enabled with the following constraints:

no looping is caused, and

no two links connected to the first bridging device are assigned to a same segment from the plurality of segments.

36. A method as in claim 34 wherein the multi-segment network device is one of the following:

a network bridging device;

a switch;

a router;

a repeater; and

a multi-segment repeater.

37. A method as in claim 34 wherein step (a) includes the following substep:

(a.1) detecting, by the agent, the information about the devices connected to the links in the plurality of links.

38. A method as in claim 34 wherein step (a) includes the following substep:

(a.1) receiving, by the agent, the information about the devices connected to the links in the plurality of links from an application that is external to the agent.

39. A method as in claim 34 wherein step (a) includes the following substep:

(a.1) receiving, by the agent, the information about the devices connected to the links in the plurality of links from a user of the multi-segment network device.

40. A system for reconfiguring a network communications topology ("NCT"), the system comprising;

a multi-segment device having a plurality of links and at least one segment; and

an agent that evaluates the NCT for bridging and repeating devices, and subsequently, for each link of the plurality of links,

assigns the link to a segment of the at least one segment or

disables the link from a segment of the at least one segment to reconfigure the NCT.

41. The system of claim 40, wherein the reconfiguration of the NCT is such that the bridging and repeating devices operate without looping.

42. The system of claim 40, wherein the reconfiguration of the NCT is such that the reconfiguration maximizes the number of available segments that can be bridged by the bridging device without looping.

43. The system of claim 40, wherein the agent assigns or disables each link of the NCT to reconfigure the NCT such that redundant connections to the bridging and repeating devices can be created.

44. The system of claim 43 wherein the agent monitors the active links of the redundant connections of the reconfigured NCT for link failure.

45. The system of claim 44, wherein the agent manages the redundant connections such that when a monitored link fails the agent reconfigures the NCT again by activating an appropriate redundant connection to replace a failed link.

46. The system of claim 40, wherein the bridging and repeating devices are external to the multi-segment device.

47. The system of claim 40, wherein the multi-segment device may be selected from the group including:

a router;

a bridging device;

a switch;

a repeater; and

a multi-segment repeater.

48. The system of claim 40, wherein the agent evaluates the appropriateness of assigning the link to the segment based on one or more conditions selected from the group including:

the attached device is the preferred bridging device;

further segments are available within the multi-segment device on which to place links attached to the given bridging device; and

placing a link on a given segment will not create a bridging or repeating loop in the attached topology; and

this is the first instance of consideration for the attached repeating device.

49. The system of claim 40, wherein the agent disables the link from the segment when a predetermined condition is met, the conditions being selected from the group including:

there are no more available segments in the multi-segment device to which links attached to the given bridging device may be assigned without creating a loop; and

a link to the attached repeating device has already been configured, thus any additional links to said repeating device must be disabled to prevent looping.

50. The system of claim 40, wherein the agent is embedded in and integrated with the multi-segment device.

51. The system of claim 40, wherein the agent is remotely connected to the multi-segment device via an out-of-band hardware control connection.

52. The system of claim 40 wherein the reconfiguration of the NCT may be triggered by manual or automatic means.

53. A method for reconfiguring a multi-segment device of a network communications topology ("NCT"), the device having a plurality of links and at least one segment, the method comprising:

evaluating the NCT for bridging and repeating devices residing external to the multi-segment device; and

reconfiguring the multi-segment device using the NCT evaluation by;

assigning a link of the plurality of links to a segment of the at least one segment or

disabling a link of the plurality of links from a segment of the at least one segment.

54. The method of claim 53, wherein the reconfiguration of the multi-segment device is such that the external bridging and repeating devices operate without looping.

55. The method of claim 53, wherein the reconfiguration of the NCT is such that the reconfiguration maximizes the number of available segments that can be bridged by the external bridging device without looping.

56. The method of claim 53, wherein the steps of assigning or disabling a link of the NCT to reconfigure the NCT may create redundant connections to the external bridging and repeating devices.

57. The method of claim 56, further including the step of monitoring the active links of the redundant connections of the reconfigured NCT for link failure.

58. The method of claim 57, further including the step of managing the redundant connections such that when a monitored link fails the step of reconfiguring occurs again to activate an appropriate redundant connection to replace the failed link.

59. A network management system for reconfiguring a network communications topology having bridging and repeating devices, the system comprising:

a multi-segment element having a plurality of links and at least one segment;

a network evaluation component that evaluates the bridging or repeating devices of the network communications topology for configuration conditions and determines a link assignment or link disablement action; and

a network control element that either

assigns a link of the plurality of links to a segment of the at least one segment or

disables a link of the plurality of links from a segment of the at least one segment

based on the determination of the network evaluation component.

60. The system of claim 59, wherein the determination for a link assignment by the network evaluation component occurs due to one or more of the following conditions selected from the group including:

the attached device is the preferred bridging device;

further segments are available within the multi-segment device on which to place links attached to the given bridging device;

placing a link on a given segment will not create a bridging or repeating loop in the attached topology; and

this is the first instance of consideration for the attached repeating device.

61. The system of claim 59, wherein the determination for a link disablement by the network evaluation component occurs due to one or more of the following conditions selected from the group including:

there are no more available segments in the multi-segment device to which links attached to the given bridging device may be assigned without creating a loop; and

a link to the attached repeating device has already been configured, thus any additional links to said repeating device must be disabled to prevent looping.