System and method for enhancing network stability by selectively controlling adjacency formation

• US 8,036,213 B1
• Filed: 03/30/2006
• Issued: 10/11/2011
• Est. Priority Date: 03/30/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Moore, Steven Edward, Savage, Donnie Van, Yang, Yi, Tran, Thuan Van, Slice, Donald Earl Jr., Ng, James L.
• Primary Examiner(s): Shah; Chirag
• Assistant Examiner(s): NGUYEN, MINH TRANG T
• Application Number:
  US11/395,846
• Time in Patent Office: 2,021 Days
• Field of Search: 370/252, 370/401, 370/349, 709/224, 709/228
• US Class Current: 370/355
• 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
• CPC Class Codes: H04L 45/123 Evaluation of link metrics techniques for monitoring network metrics H04L43/08
• CPC Class Codes: H04W 40/12 based on transmission quality or channel quality

Abstract

A system and method for facilitating connecting a switch to a network to improve network performance. In an illustrative embodiment, the system includes a first module for determining when the switch is initially connected to a network and providing a signal in response thereto. A second module selectively forms adjacencies with peers of the switch in response to the signal and based on one or more predetermined parameters. In a more specific embodiment, the switch is a router or Layer-3 (L3) switch. The one or more predetermined parameters include a load factor, values pertaining to capabilities of a processor included in the router, bandwidth capabilities of the interface and/or the router, internal router queue counts, and so on. The router employs a routing protocol such as Enhanced Interior Gateway Routing Protocol (EIGRP). The second module throttles and adjacency-formation rate based on the predetermined parameters.

Claims

1. A system comprising:

a processor comprising integrated circuits;

a first module device configured to interact with the processor to determine when a switch is initially connected to a network and to provide a signal in response thereto; and

a second module device, configured to interact with the processor to selectively form adjacencies between the switch and a plurality of subsets of peers of the switch in response to the signal and based on one or more predetermined parameters, wherein the second module device includes one or more routines for selectively controlling a rate at which adjacencies are formed with the switch based on the one or more predetermined parameters, wherein the one or more routines are configured to control the rate at which adjacencies are formed by controlling the rate at which adjacency-forming messages are sent between the second module device and the peers of a particular subset, wherein the rate determines a number of adjacencies formed with each subset of peers, and wherein the second module device is configured to process slow-start instructions.

2. The system of claim 1 wherein the switch includes a router.

3. The system of claim 2 wherein the one or more predetermined parameters include a load factor.

4. The system of claim 3 wherein the load factor incorporates numbers of peers connected to the network and the router via a similar interface.

5. The system of claim 2 wherein the one or more predetermined parameters include one or more values pertaining to capabilities of a processor included in the router.

6. The system of claim 2 wherein the one or more predetermined parameters include bandwidth capabilities of at least one of an interface and the router.

7. The system of claim 2 wherein the one or more predetermined parameters include path delay values associated with an interface.

8. The system of claim 2 wherein the one or more predetermined parameters include internal router queue counts associated with the router.

9. The system of claim 2 wherein the router includes a vector-based routing protocol.

10. The system of claim 9 wherein the vector-based routing protocol includes enhanced interior gateway routing protocol (EIGRP).

11. The system of claim 9 wherein the router includes a link-state routing protocol.

12. The system of claim 11 wherein the link-state routing protocol includes vector-based routing protocol includes open shortest path first (OSPF) protocol.

13. The system of claim 11 wherein the link-state routing protocol includes intermediate-system-to-intermediate-system (IMIS) protocol.

14. A router comprising:

a processor comprising integrated circuits;

a slow-start module device, configured to interact with the processor, that contains slow-start instructions for controlling a rate at which adjacencies are formed between a router and a plurality of subsets of peers of the router based on the one or more predetermined factors, wherein the slow-start instructions are configured to control the rate at which adjacencies are formed by controlling the rate at which adjacency-forming messages are sent between the router and the peers of a particular subset, and wherein the rate determines a number of adjacencies formed with each subset of peers; and

a routing module device in communication with the slow-start module device, wherein the routing module device is responsive to control signals received from the slow-start module device.

15. The system of claim 14 wherein the slow-start instructions include first means for determining when the router is initially connected to an interface of a network and providing a signal in response thereto.

16. The system of claim 15 wherein the slow-start instructions further include second means for issuing the control signals to the routing module device, wherein the control signals are configured to adjust the rate at which adjacencies are formed, based on one or more predetermined factors.

17. The system of claim 16 wherein the one or more predetermined factors include one or more of a load factor, capabilities of a processor included in the router;

numbers of peers connected to the network and the router via a similar interface;

bandwidth capabilities of at least one of the interface and the router;

path delay values associated with the interface; and

internal router queue counts associated with the router.

18. An apparatus comprising:

one or more processors comprising integrated circuits; and

a non-transitory computer-readable medium including instructions executable by the one or more processors for;

determining when a router is initially connected to a network and providing a signal in response thereto; and

selectively forming adjacencies between the router and a plurality of subsets of peers of the router in response to the signal and based on one or more predetermined parameters, wherein one or more routines selectively control a rate at which adjacencies are formed based on the one or more predetermined parameters, wherein the one or more routines are configured to control the rate at which adjacencies are formed by controlling the rate at which adjacency-forming messages are sent between the router and the peers of a particular subset, and wherein the rate determines a number of adjacencies formed with each subset of peers.

19. A system comprising:

a first device, at least partially implemented in hardware, for determining when a router is initially connected to a network and providing a signal in response thereto; and

a second device for selectively forming adjacencies between the router and a plurality of subsets of peers of the router in response to the signal and based on one or more predetermined parameters, wherein one or more routines selectively control a rate at which adjacencies are formed based on the one or more predetermined parameters, wherein the one or more routines are configured to control the rate at which adjacencies are formed by controlling the rate at which adjacency-forming messages are sent between the router and the peers of a particular subset, and wherein the rate determines a number of adjacencies formed with each subset of peers.

20. A method comprising:

determining, by a first device, when a router is initially connected to a network and providing a signal in response thereto; and

selectively forming, by a second device, adjacencies between the router and a plurality of subsets of peers of the router in response to the signal and based on one or more predetermined parameters, wherein one or more routines selectively control a rate at which adjacencies are formed based on the one or more predetermined parameters, wherein the one or more routines are configured to control the rate at which adjacencies are formed by controlling the rate at which adjacency-forming messages are sent between the router and the peers of a particular subset, and wherein the rate determines a number of adjacencies formed with each subset of peers.