Leaking routes in a service chain

• US 10,063,468 B2
• Filed: 01/15/2016
• Issued: 08/28/2018
• Est. Priority Date: 01/15/2016
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Bosch, Hendrikus G. P., Mullender, Sape Jurrien, Napper, Jeffrey, Kumar, Surendra M., Duminuco, Alessandro
• Primary Examiner(s): Ton, Dang
• Application Number:
  US14/997,212
• Publication Number:
  US 20170208000A1
• Time in Patent Office: 956 Days
• Field of Search: 370392
• CPC Class Codes: H04L 45/38 Flow based routing
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering

Abstract

Particular embodiments described herein provide for a communication system that can be configured for receiving, at a network element, a flow offload decision for a first service node. The flow offload decision can include a portion of a service chain for processing a flow and updating next hop flow based routing information for the flow. A next hop in the flow can insert flow specific route information in its routing tables to bypass a packet forwarder serving the service that offloaded the flow in the reverse direction.

Claims

1. A method, comprising:

receiving, at a network element, a flow offload decision for a first service node in a portion of a service chain for processing a flow; and

updating next hop flow based routing information for the flow, wherein a next hop in the flow can insert flow specific route information in its routing tables to bypass a packet forwarder serving a service that offloaded the flow.

2. The method of claim 1, wherein each packet forwarder in the flow can be defined by a service path identifier and each packet that traverses the service chain carries the service path identifier in a network services header.

3. The method of claim 2, wherein each packet forwarder is provided with next and previous hop information for the service path identifier.

4. The method of claim 1, wherein a service path identifier routing table is stored on the packet forwarder with flow specific routes that can be extended.

5. The method of claim 1, wherein information carried forward is previous hop information for the flow and can include a flow route update.

6. The method of claim 1, wherein the next hop flow based routing information for the flow is discarded after the flow ends or after a specific amount of time.

7. The method of claim 1, further comprising:

delaying the update of a routing table in a previous hop in a reverse direction of the flow.

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

receiving, at a network element, a flow offload decision for a first service node in a portion of a service chain for processing a flow; and

updating next hop flow based routing information for the flow, wherein a next hop can insert flow specific route information in its routing tables to bypass a packet forwarder serving the service that offloaded the flow.

9. The logic of claim 8, wherein each packet forwarder in the flow can be defined by a service path identifier and each packet that traverses the service chain carries the service path identifier in a network services header.

10. The logic of claim 9, wherein each packet forwarder is provided with next and previous hop information for the service path identifier.

11. The logic of claim 8, wherein a service path identifier routing table is stored on the packet forwarder with flow specific routes that can be extended.

12. The logic of claim 8, wherein information carried forward is previous hop information for the flow and can include a flow route update.

13. The logic of claim 8, wherein the next hop flow based routing information for the flow is discarded after the flow ends, after a specific amount of time, or when the capacity of the flow routing table is exhausted.

14. An apparatus, comprising:

a memory element configured to store data,

a processor operable to execute instructions associated with the data, and

a routing module configured to;

receive a flow offload decision for a first service node in a portion of a service chain for processing a flow, wherein the service chain is identified by a service path identifier; and

update next hop flow based routing information for the flow, wherein a next hop in the flow can insert flow specific route information in its routing tables to bypass a packet forwarder serving a service that offloaded the flow in a reverse direction.

15. The apparatus of claim 14, wherein each packet forwarder in the flow can be defined by a unique service path identifier and each packet that traverses the service chain carries the unique service path identifier in a network services header.

16. The apparatus of claim 15, wherein the routing module is provided with next and previous hop information for the unique service path identifier.

17. The apparatus of claim 14, wherein the routing module includes a routing table and the routing table with flow specific routes can be extended.

18. The apparatus of claim 17, wherein information carried forward is previous hop information for that flow and can include a flow route update.

19. The apparatus of claim 14, wherein the next hop flow based routing information for the flow is discarded after the flow ends, after a specific amount of time, or when a flow routing table capacity is exhausted.

20. The apparatus of claim 14, wherein the next hop flow based routing information for the flow is discarded after a predetermined amount of time or when a routing table capacity is exhausted.