Load sharing and redundancy scheme

• US 9,276,834 B2
• Filed: 11/18/2011
• Issued: 03/01/2016
• Est. Priority Date: 06/29/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Kanekar, Bhushan Mangesh, Rajendran, Saravanakumar, Davar, Jonathan
• Primary Examiner(s): Jagannathan, Melanie
• Application Number:
  US13/300,377
• Publication Number:
  US 20120076048A1
• Time in Patent Office: 1,565 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/58 Association of routers

Abstract

Methods and apparatus for providing a device for forwarding packets in a network are disclosed. A first router and a second router having a shared set of interfaces are provided, enabling the first router and the second router to share forwarding data for forwarding packets on the shared set of interfaces.

Claims

1. A computing device comprising:

a chassis;

a communication backplane;

a first router disposed in the chassis, the first router being configured to operate as a master router and to generate and store a configuration file; and

a second router disposed in the chassis, the second router being configured to operate as a slave router and to share a set of interfaces with the first router and to generate and store at least a partial copy of the configuration file;

wherein the first router is configured to transmit information indicating a hardware state of the computing device and spanning tree protocol updates to the second router over the shared set of interfaces, and to communicate a failure of the first router to the second router over the communication backplane.

2. The computing device of claim 1, wherein the first router and the second router share a set of security information.

3. The computing device of claim 1, wherein the set of interfaces enable the first router and the second router to share forwarding data for forwarding packets on the set of interfaces.

4. The computing device of claim 1, wherein both the first router and the second router run Hot Standby Redundancy Protocol (HSRP).

5. The computing device of claim 1, wherein both the first router and the second router run a redundancy protocol.

6. The computing device of claim 1, wherein each of the first router and the second router maintains its own spanning tree database, forwarding table, and routing table.

7. The computing device of claim 2, wherein the set of security information comprises access lists.

8. The computing device of claim 1, wherein the first router and the second router are configured with unique priorities, wherein the unique priorities are used to assign one of the first router and the second router as the master router.

9. The computing device of claim 1, wherein the first router is configured to assert a signal via the communication backplane indicating that the first router is the master router.

10. The computing device of claim 1, wherein the master router is configured to run a layer 2 spanning tree protocol until the master router fails, at which time the slave router is configured to run the layer 2 spanning tree protocol.

11. A method, comprising:

by a first router disposed in a chassis of a computing device;

transmitting a first signal to a second router disposed in the chassis, the first signal indicating that the first router is operating as a master router, the second router sharing a set of interfaces with the first router;

transmitting information indicating a hardware state of the computing device and spanning tree protocol updates to the second router over the shared set of interfaces; and

transmitting a second signal to the second router via a communication backplane of the computing device in response to a failure of the first router.

12. An apparatus, comprising:

a backplane; and

first and second routers disposed within a single chassis and sharing a set of interfaces;

wherein the first router and the second router implement a redundancy protocol such that one of the first and second routers operates as a master router and another one of the first and second routers operates as a slave router;

wherein a failure of the master router is detectable by the slave router via the backplane; and

wherein the master router is configured to transmit information indicating a hardware state of the apparatus and spanning tree protocol updates to the slave router over the shared set of interfaces.

13. The apparatus as recited in claim 12, wherein the redundancy protocol is Hot Standby Redundancy Protocol (HSRP).

14. The apparatus as recited in claim 12, wherein the master router is configured to send a signal to the slave router via the backplane of the apparatus upon a failure of the master router.

15. The apparatus as recited in claim 12, wherein the master router is configured to send a signal to the slave router via the backplane of the apparatus to indicate that the master router is operating as the master router for the apparatus.