System and method for managing topology changes in a network environment

• US 8,982,733 B2
• Filed: 03/04/2011
• Issued: 03/17/2015
• Est. Priority Date: 03/04/2011
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Bulusu, Shekher, Sane, Sanjay, Desai, Ronak
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Moutaouakil, Mounir
• Application Number:
  US13/041,148
• Publication Number:
  US 20120224510A1
• Time in Patent Office: 1,474 Days
• Field of Search: 370241-242, 370254-256
• US Class Current: 370/256
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/03 by updating link state protocols
• CPC Class Codes: H04L 45/48 Routing tree calculation

Abstract

A method is provided in one example embodiment and includes receiving a spanning tree protocol topology change notification (STP TCN) in a network; removing topology data for a first plurality of gateways associated with a first network segment ID that is shared by a particular gateway that communicated the STP TCN; and communicating an edge TCN to a second plurality of gateways associated with a second network segment ID and for which topology data has not been removed based on the STP TCN.

Claims

1. A method, comprising:

receiving a spanning tree protocol topology change notification (STP TCN) in a network;

removing topology data using an STP for a first plurality of gateways associated with a first network segment ID that is shared by a particular gateway that communicated the STP TCN; and

communicating an edge TCN over an intermediate system to intermediate system (IS-IS) protocol to a second plurality of gateways associated with a second network segment ID and for which topology data has not been removed based on the STP TCN; and

removing topology data from the second plurality of gateways that was learned from a communicating network element that communicated the edge TCN without communicating the STP TCN into a second network associated with the second network segment ID.

2. The method of claim 1, wherein the network includes a Data Center Ethernet (DCE) network, a first Classical Ethernet (CE) network, and a second CE network, which collectively form a layer-2 (L2) domain.

3. The method of claim 1, wherein removing the topology data comprises removing Media Access Control (MAC) addresses from a MAC table, and wherein the first and second network segment IDs are encoded in respective MAC addresses.

4. The method of claim 1, wherein the edge TCN contains a generate bit, which causes a receiving network element to remove MAC addresses learned from a communicating network element that provided the edge TCN.

5. The method of claim 1, wherein the edge TCN contains a propagate bit, and wherein a receiving network element processes the edge TCN if it belongs to a same CE segment and removes MAC addresses on STP designated ports.

6. The method of claim 1, wherein a manual configuration mechanism is used to associate the network segment IDs with respective gateways.

7. The method of claim 1, wherein STP hello messages are used to associate the network segment IDs with respective gateways.

8. Logic encoded in non-transitory media that includes code for execution and when executed by a processor operable to perform operations comprising:

receiving a spanning tree protocol topology change notification (STP TCN) in a network;

removing topology data using an STP for a first plurality of gateways associated with a first network segment ID that is shared by a particular gateway that communicated the STP TCN; and

communicating an edge TCN over an intermediate system to intermediate system (IS-IS) protocol to a second plurality of gateways associated with a second network segment ID and for which topology data has not been removed based on the STP TCN; and

removing topology data from the second plurality of gateways that was learned from a communicating network element that communicated the edge TCN without communicating the STP TCN into a second network associated with the second network segment ID.

9. The logic of claim 8, wherein the network includes a Data Center Ethernet (DCE) network, a first Classical Ethernet (CE) network, and a second CE network, which collectively form a layer-2 (L2) domain.

10. The logic of claim 8, wherein removing the topology data comprises removing Media Access Control (MAC) addresses from a MAC table, and wherein the first and second network segment IDs are encoded in respective MAC addresses.

11. The logic of claim 8, wherein the edge TCN contains a generate bit, which causes a receiving network element to remove MAC addresses learned from a communicating network element that provided the edge TCN.

12. The logic of claim 8, wherein the edge TCN contains a propagate bit, and wherein a receiving network element processes the edge TCN if it belongs to a same CE segment and removes MAC addresses on STP designated ports.

13. The logic of claim 8, wherein STP hello messages are used to associate the network segment IDs with respective gateways.

14. An apparatus, comprising:

a memory element configured to store electronic code;

a processor operable to execute instructions associated with the electronic code; and

a routing module configured to interface with the processor such that the apparatus is configured for;

receiving a spanning tree protocol topology change notification (STP TCN) in a network;

removing topology data using an STP for a first plurality of gateways associated with a first network segment ID that is shared by a particular gateway that communicated the STP TCN; and

communicating an edge TCN over an intermediate system to intermediate system (IS-IS) protocol to a second plurality of gateways associated with a second network segment ID and for which topology data has not been removed based on the STP TCN; and

removing topology data from the second plurality of gateways that was learned from a communicating network element that communicated the edge TCN without communicating the STP TCN into a second network associated with the second network segment ID.

15. The apparatus of claim 14, wherein the network includes a Data Center Ethernet (DCE) network, a first Classical Ethernet (CE) network, and a second CE network, which collectively form a layer-2 (L2) domain.

16. The apparatus of claim 14, wherein removing the topology data comprises removing Media Access Control (MAC) addresses from a MAC table, and wherein the first and second network segment IDs are encoded in respective MAC addresses.

17. The apparatus of claim 14, wherein the edge TCN contains a generate bit, which causes a receiving network element to remove MAC addresses learned from a communicating network element that provided the edge TCN.

18. The apparatus of claim 14, wherein the edge TCN contains a propagate bit, and wherein a receiving network element processes the edge TCN if it belongs to a same CE segment and removes MAC addresses on STP designated ports.

19. The apparatus of claim 15, wherein STP hello messages are used to associate the network segment IDs with respective gateways.