Detection of overlapping subnets in a network

• US 10,644,946 B2
• Filed: 07/28/2017
• Issued: 05/05/2020
• Est. Priority Date: 06/19/2017
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Harneja, Sanchay, Sundaresan, Sanjay, Jagannati, Harsha
• Primary Examiner(s): Whipple, Brian
• Assistant Examiner(s): Fan, John
• Application Number:
  US15/663,618
• Publication Number:
  US 20180367392A1
• Time in Patent Office: 1,012 Days
• Field of Search: 709220
• CPC Class Codes: H04L 41/06 Management of faults, events, alarms or notifications
• CPC Class Codes: H04L 41/0866 Checking the configuration
• CPC Class Codes: H04L 41/0873 Checking configuration conflicts between network elements
• CPC Class Codes: H04L 41/145 involving simulating, designing, planning or modelling of a network

Abstract

Disclosed are systems, methods, and computer-readable media for assuring tenant forwarding in a network environment. Network assurance can be determined in layer 1, layer 2 and layer 3 of the networked environment including, internal-internal (e.g., inter-fabric) forwarding and internal-external (e.g., outside the fabric) forwarding in the networked environment. The network assurance can be performed using logical configurations, software configurations and/or hardware configurations.

Claims

1. A system for performing a network assurance check of proper deployment of a configuration in a fabric, the system comprising:

at least one memory configured to store data; and

at least one processor operable to execute instructions associated with the data which, when executed by the at least one processor, cause the at least one processor to;

receive, from a controller, a global logical model in a first format, the global logical model containing endpoint communication instructions indicating how endpoints connected to a network fabric communicate within the fabric;

receive, from one or more network devices within the fabric, a software model, the software model being at least a subset of instructions from the global logical model in a second format executable on the one or more network devices, the subset of instructions being operability instructions regarding operability of the one or more network devices;

determine whether one or more bridge domain (BD) subnets, in the global logical model and the software model, overlap;

when the overlap is not identified, determine the one or more BD subnets have been properly deployed;

when the overlap is identified, determine whether the overlap satisfies an exception; and

when the exception is not satisfied, determine the one or more BD subnets have been properly deployed.

2. The system of claim 1, wherein the instructions further cause the at least one processor to:

inspect IP addresses of the software model;

determine the overlap when two or more of the IP addresses match.

3. The system of claim 2, wherein inspection of the IP addresses is performed in each virtual routing and forwarding instance (VRF) of each of the one or more network devices.

4. The system of claim 1, wherein the exception is when the one or more BD subnets are within a learned route.

5. The system of claim 1, wherein the exception is when the one or more BD subnets are the same.

6. The system of claim 1, wherein determining the one or more BD subnets have been properly deployed includes generating an error event.

7. A method for performing a network assurance check of proper deployment of a configuration in a fabric, the method comprising:

receiving from a controller, a global logical model in a first format, the global logical model containing endpoint communication instructions indicating how endpoints connected to a network fabric communicate within the fabric;

receiving from one or more network devices within the fabric, a software model, the software model being at least a subset of instructions from the global logical model in a second format executable on the one or more network devices, the subset of instructions being operability instructions regarding operability of the one or more network devices;

determining whether one or more bridge domain (BD) subnets, in the global logical model and the software model, overlap;

when the overlap is not identified, determining the one or more BD subnets have been properly deployed;

when the overlap is identified, determining whether the overlap satisfies an exception; and

when the exception is not satisfied, determine the one or more BD subnets have been properly deployed.

8. The method of claim 7, further comprising:

inspecting IP addresses of the software model;

determining the overlap when two or more of the IP addresses match.

9. The method of claim 8, wherein the inspecting is performed in each virtual routing and forwarding instance (VRF) of each of the one or more network devices.

10. The method of claim 7, wherein the exception is when the one or more BD subnets are within a learned route.

11. The method of claim 7, wherein the exception is when the one or more BD subnets are the same.

12. The method of claim 7, further comprising:

generating an error event in response to overlap without an applicable exception.

13. At least one non-transitory computer readable medium storing instructions which, when executed by a processor, cause the processor to:

receive, from a controller, a global logical model in a first format, the global logical model containing communication information instructions how endpoints connected to a network fabric communicate within the network fabric;

receive, from one or more network devices within the network fabric, a software model, the software model being at least a subset of instructions from the global logical model in a second format executable on the one or more network devices, the subset of instructions being operability instructions regarding operability of the one or more network devices;

determine whether one or more bridge domain (BD) subnets, in the global logical model and the software model, overlap;

when the overlap is not identified, determine the one or more BD subnets have been properly deployed;

when the overlap is not identified, determine whether the overlap satisfies an exception;

when the exception is not satisfied, determine the one or more BD subnets have been properly deployed.

14. The at least one non-transitory computer readable medium of claim 13, wherein the instructions further cause the processor to:

inspect IP addresses of the software model;

determine the overlap when two or more of the IP addresses match.

15. The at least one non-transitory computer readable medium of claim 14, wherein inspection of the IP addresses is performed in each virtual routing and forwarding instance (VRF) of each of the one or more network devices.

16. The at least one non-transitory computer readable medium of claim 13, wherein the an exception is when the one or more BD subnets are within a learned route.

17. The at least one non-transitory computer readable medium of claim 13, wherein the exception is when the one or more BD subnets are the same.