SYSTEMS AND METHODS FOR TESTING NETWORKS WITH A CONTROLLER

• US 20150138993A1
• Filed: 11/20/2013
• Published: 05/21/2015
• Est. Priority Date: 11/20/2013
• Status: Active Grant

• Current Assignee: Arista Networks, Inc.
• Original Assignee: Big Switch Networks, Inc. (Arista Networks, Inc.)
• Inventors: Forster, R. Kyle, Zhou, Shudong, Sherwood, Robert W., Parraga, Jason
• Granted Patent: US 9,819,551 B2
• Time in Patent Office: Days
• US Class Current: 370/248
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 41/122 of virtualised topologies, e.g. software-defined networks [SDN] or network function virtualisation [NFV]
• CPC Class Codes: H04L 41/24 using dedicated network management hardware
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: Y02D 30/00 Reducing energy consumption in communication networks

Abstract

A controller may control switches such as physical and software switches in a network. The controller may generate virtual switches from groups of end hosts in forming a virtual network topology. The controller may receive one or more network policy rules that govern network traffic through the switches. For a given network policy rule, the controller may perform a test in determining whether the network satisfies the network policy rule. The test may be performed based on a testing rule identifying test parameters and expected test results. The controller may perform tests in determining whether the network satisfies the testing rule and the corresponding network policy rule. The tests may be performed via simulation at the controller or by injecting a tagged test packet into the network.

Claims

1. A method of using a controller that controls switches in a network having end hosts that are coupled to the switches, the method comprising:

receiving a given network policy rule; and

performing a test in determining whether the network satisfies the given network policy rule.

2. The method defined in claim 1 further comprising:

generating virtual switches from groups of end hosts, wherein each virtual switch has virtual ports assigned to respective end hosts and wherein the given network policy rule is defined for a given virtual port; and

generating a virtual network topology from the virtual switches, wherein performing the test in determining whether the network satisfies the given network policy rule comprises performing the test based on the generated virtual network topology.

3. The method defined in claim 2 further comprising:

receiving a testing rule that identifies test parameters and expected test results.

4. The method defined in claim 3 wherein performing the test in determining whether the network satisfies the given network policy rule based on the generated virtual network topology comprises:

generating a test packet based on the test parameters of the received testing rule.

5. The method defined in claim 4 wherein performing the test in determining whether the network satisfies the given network policy rule based on the generated virtual network topology further comprises:

simulating packet traversal of the test packet through a virtual path of the virtual network topology.

6. The method defined in claim 5 wherein the controller implements a plurality of network policy rules that include the given network policy rule, the method further comprising:

identifying network policy rules that are triggered during simulation of the packet traversal of the virtual network topology.

7. The method defined in claim 6 wherein performing the test in determining whether the network satisfies the given network policy rule based on the generated virtual network topology further comprises:

determining a set of switches that form an underlying path of the virtual path.

8. The method defined in claim 7 wherein performing the test in determining whether the network satisfies the given network policy rule based on the generated virtual network topology further comprises:

generating flow table entries that implement the underlying path of the virtual path without providing the flow table entries to the set of switches.

9. The method defined in claim 8 wherein performing the test in determining whether the network satisfies the given network policy rule based on the generated virtual network topology further comprises:

comparing results of the simulated packet traversal with the expected results to determine whether the network satisfies the given network policy rule.

10. The method defined in claim 9 wherein the expected results of the testing rule include a list of network policy rules that are expected to be triggered and wherein comparing the results of the simulated packet traversal with the expected results to determine whether the network satisfies the given network policy rule comprises:

comparing the list of network policy rules to the triggered network policy rules.

11. The method defined in claim 4 wherein performing the test in determining whether the network satisfies the given network policy rule based on the generated virtual network topology further comprises:

generating a tagged test packet from the test packet;

injecting the tagged test packet into the network; and

based on the expected results of the testing rule and on information received from the switches on the tagged test packet, determining whether the network satisfies the given network policy rule.

12. The method defined in claim 11 wherein performing the test in determining whether the network satisfies the given network policy rule based on the generated virtual network topology further comprises:

providing flow table entries to the switches that direct the switches to send information on the tagged test packet to the controller, wherein the flow table entries prevent the switches from forwarding the tagged test packet to a destination end host of the tagged test packet; and

based on the information from the switches and the expected results of the testing rule, determining whether the network satisfies the given network policy rule.

13. A method of using a controller that controls switches in a network having end hosts that are coupled to the switches, the method comprising:

maintaining network topology information for the network;

receiving a user-defined testing rule;

based on the user-defined testing rule, generating a test packet; and

determining whether the network satisfies the user-defined testing rule by processing the test packet based on the network topology information.

14. The method defined in claim 13 further comprising:

forming virtual switches from groups of end hosts, wherein the network topology information includes network topology information for the switches and virtual network topology information for the virtual switches.

15. The method defined in claim 14 wherein the user-defined testing rule includes expected results and test parameters identifying a source end host and a destination end host, wherein the test packet identifies the source end host and the destination end host of the user-defined testing rule, and wherein processing the test packet comprises:

simulating traversal of the network packet from the source end host to the destination end host through the network based on the network topology information.

16. The method defined in claim 15 wherein determining whether the network satisfies the user-defined testing rule comprises:

determining whether the simulated traversal of the network packet matches the expected results of the user-defined testing rule.

17. A method of using a controller that controls switches in a network, the method comprising:

receiving a user-defined testing rule;

based on the user-defined testing rule, generating a tagged test packet; and

injecting the tagged test packet into the network.

18. The method defined in claim 17 wherein generating the tagged test packet comprises:

generating a test packet; and

inserting identification information into header fields of the test packet to produce the tagged test packet.

19. The method defined in claim 17 wherein generating the tagged test packet comprises:

generating a test packet; and

encapsulating the test packet using identification information to produce the tagged test packet.

20. The method defined in claim 17 further comprising:

controlling the switches to provide information on the test packet in response to receiving the tagged test packet; and

identifying a path traversed by the tagged test packet based on the information provided by the switches.

21. The method defined in claim 20 wherein the user-defined testing rule includes expected results, the method further comprising:

based on the identified path, determining whether the network satisfies the expected results of the user-defined testing rule.