USING TRANSACTIONS TO COMPUTE AND PROPAGATE NETWORK FORWARDING STATE

• US 20140247753A1
• Filed: 04/18/2013
• Published: 09/04/2014
• Est. Priority Date: 04/18/2012
• Status: Active Grant

• Current Assignee: Nicira Incorporated (Broadcom, Inc.)
• Original Assignee: Nicira Incorporated (Broadcom, Inc.)
• Inventors: Koponen, Teemu, Padmanabhan, Amar
• Granted Patent: US 9,306,843 B2
• Time in Patent Office: Days
• US Class Current: 370/255
• CPC Class Codes: G06F 2009/4557 Distribution of virtual machine instances; Migration and load balancing
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects
• CPC Class Codes: H04L 41/0654 using network fault recovery ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437
• CPC Class Codes: H04L 41/08 Configuration management of networks or network elements address allocation H04L61/50
• CPC Class Codes: H04L 41/0803 Configuration setting
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements
• CPC Class Codes: H04L 41/0894 Policy-based network configuration management
• CPC Class Codes: H04L 41/0895 Configuration of virtualised networks or elements, e.g. virtualised network function or OpenFlow elements
• CPC Class Codes: H04L 41/122 of virtualised topologies, e.g. software-defined networks [SDN] or network function virtualisation [NFV]
• CPC Class Codes: H04L 43/0823 Errors, e.g. transmission errors
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/64 using an overlay routing layer
• CPC Class Codes: H04L 45/72 Routing based on the source address
• CPC Class Codes: H04L 49/70 Virtual switches

Abstract

For a controller for managing a network comprising several managed forwarding elements that forward data in the network, a method for configuring a managed forwarding element is described. The method generates a first set of flow entries for defining forwarding behaviors of the managed forwarding element based on a current network policy for a logical network implemented in the several managed forwarding elements. The method sends the first set of flow entries to the managed forwarding element in order for the managed forwarding element to forward data that the managed forwarding element directly receives from an end machine based on the current network policy. The method generates a second set of flow entries for modifying forwarding behaviors of the managed forwarding element based on a new network policy for the logical network. The method sends the second set of flow entries to the managed forwarding element in order for the managed forwarding element to forward the data based on the new network policy.

Claims

1. For a controller for managing a network comprising a plurality of managed forwarding elements that forward data in the network, a method for configuring a managed forwarding element, the method comprising:

generating a first set of flow entries for defining forwarding behaviors of the managed forwarding element based on a current network policy for a logical network implemented in the plurality of managed forwarding elements;

sending the first set of flow entries to the managed forwarding element in order for the managed forwarding element to forward data that the managed forwarding element directly receives from an end machine based on the current network policy;

generating a second set of flow entries for modifying forwarding behaviors of the managed forwarding element based on a new network policy for the logical network; and

sending the second set of flow entries to the managed forwarding element in order for the managed forwarding element to forward the data based on the new network policy,

wherein the managed forwarding element forwards the data by making a set of logical forwarding decisions for identifying a physical port to which a logical egress port of a logical forwarding element is mapped, wherein the logical forwarding element is implemented in the plurality of managed forwarding elements.

2. The method of claim 1, wherein other managed forwarding elements do not make any logical forwarding decisions for the data.

3. The method of claim 1, wherein the managed forwarding element starts using the second set of flow entries when the managed forwarding element completely receives the second set of flow entries.

4. The method of claim 1 further comprising sending a command to the managed forwarding element for the managed forwarding element to start using the second set of flow entries.

5. The method of claim 1, wherein the managed forwarding element removes the first set of flow entries from the managed forwarding element when a period of time elapses after receiving the second set of flow entries.

6. For a controller for managing a network comprising a plurality of managed forwarding elements that forward data in the network, a method for configuring the managed forwarding elements, the method comprising:

generating a first set of configuration data for configuring a managed forwarding elements as a first-hop forwarding element for (i) receiving a packet directly from an end machine that is a source of the packet and (ii) forwarding the packet towards an end machine that is a destination of the packet;

generating a second set of configuration data for configuring a set of managed forwarding elements as non-first-hop forwarding elements for (i) receiving the packet not directly from the source end machine and (ii) forwarding the packet towards the destination end machine; and

sending the second set of configuration data to the set of managed forwarding elements prior to sending the first set of configuration data to the managed forwarding element.

7. The method of claim 6 further comprising:

before sending the second set of configuration data to the set of managed forwarding elements;

generating a third set of configuration data for (i) configuring the managed forwarding element as a first-hop forwarding element and (ii) configuring the managed forwarding element to attach version information to a particular packet that the managed forwarding element as a first-hop forwarding element receives and forwards;

generating a fourth set of configuration data for configuring the set of managed forwarding elements as non-first-hop forwarding elements;

sending the third set of configuration data to the managed forwarding element; and

sending the fourth set of configuration data to the set of managed forwarding elements,

wherein after receiving the second set of configuration data from the controller, the set of managed forwarding elements uses the version information to choose the fourth set of configuration data over the second set of configuration data to use to forward the particular packet that the set of managed switching elements as non-first-hop forwarding elements receive and forward.

8. The method of claim 7, wherein the version information has a size of a single binary bit.

9. The method of claim 7 further comprising:

sending the first set of flow entries to the managed forwarding element,

wherein the first set of flow entries is further for configuring the managed forwarding element to attach different version information to the packet that the set of managed forwarding elements as a first-hop forwarding element receives and forwards,

wherein after receiving the second set of flow entries, the set of managed forwarding elements uses the different version information to choose the second set of configuration data over the fourth set of configuration data to use to forward the packet that the set of managed switching elements receives as non-first-hop forwarding elements.

10. The method of claim 7 further comprising configuring the managed forwarding elements to remove the third set of configuration data after a certain period of time elapses after receiving the first set of configuration data.

11. The method of claim 7 further comprising sending a command to the managed forwarding elements to remove the third set of configuration data after receiving the first set of configuration data.

12. The method of claim 6, wherein the managed forwarding element operates in a host, wherein the source end machine operates within the same host.

13. The method of claim 6, wherein the second set of configuration data is further for configuring a particular managed forwarding element of the set of managed forwarding elements as a last-hop forwarding element for sending a packet, which the particular forwarding element receives as a non-first-hop forwarding element, to the destination end machine directly.

14. The method of claim 13, wherein the particular managed forwarding element operates in a host, wherein the destination end machine operates within the same host.

15. For a controller for managing a network comprising managed forwarding elements that forward data in the network, a method for configuring a set of managed forwarding elements, the method comprising:

generating (i) a first set of flow entries for configuring the set of managed forwarding elements as first-hop forwarding elements that forward data received directly from a set of end machines and (ii) a second set of flow entries for configuring the set of managed forwarding elements as non-first-hop forwarding elements that forward data not received from the set of end machines; and

sending the second set of flow entries to the set of managed forwarding elements prior to sending the first set of flow entries to the set of managed forwarding elements.

16. The method of claim 15 further comprising:

before sending the second set of flow entries;

generating a third set of flow entries for (i) configuring the set of managed forwarding elements as first-hop forwarding elements and (ii) configuring the set of managed forwarding elements to attach version information to data that the set of managed forwarding elements as first-hop forwarding elements receives and forwards;

generating a fourth set of flow entries for configuring the set of managed forwarding elements as non-first-hop forwarding elements;

sending the third and fourth sets of flow entries to the set of managed forwarding elements,

wherein after receiving the second set of flow entries from the controller, the set of managed forwarding elements uses the version information to choose the fourth set of flow entries over the second set of flow entries to use to forward the data that the set of managed switching elements receives as non-first-hop forwarding elements

17. The method of claim 16, wherein the version information has a size of a single binary bit.

18. The method of claim 16 further comprising:

sending the first set of flow entries to the set of managed forwarding elements,

wherein the first set of flow entries is further for configuring the set of managed forwarding elements to attach different version information to the data that the set of managed forwarding elements as first-hop forwarding elements receives and forwards,

wherein after receiving the second set of flow entries, the set of managed forwarding elements uses the different version information to choose the second set of flow entries over the fourth set of flow entries to use to forward the data that the set of managed switching elements receives as non-first-hop forwarding elements.

19. The method of claim 16 further comprising configuring the set of managed forwarding elements to remove the third and fourth sets of flow entries after a certain period of time elapses after receiving the first set of flow entries.

20. The method of claim 16 further comprising sending a command to the set of managed forwarding elements to remove the third and fourth sets of flow entries after receiving the first set of flow entries.

21. For a managed forwarding element for forwarding data in a network, a method for forwarding data comprising:

forwarding data based on old forwarding state information that defines forwarding behaviors of the managed forwarding element, the old forwarding state information received through a plurality of communication channels established between the managed forwarding element and a controller that sends forwarding state information to the managed forwarding element;

receiving new forwarding state information from the controller through the communication channel established with the controller, the new forwarding state information for modifying the forwarding behaviors of the managed forwarding element, the new forwarding state received as sets of transactional input flow entries through the communication channels, one set of transactional input flow entries received through a particular channel, the other sets of transactional input flow entries received through other channels of the plurality of channels; and

using the new forwarding state information to forward data only after completely receiving the set of transactional input flow entries through the particular channel.

22. The method of claim 21, wherein each set of transactional input flow entries comprises an indicator that indicates that, when received by the managed forwarding elements, all of the transactional input flow entries of the set of the transactional input flow entries have been received at the managed forwarding elements.

23. The method of claim 21, wherein the managed forwarding element operates in a host, the method further comprising:

receiving data from the network, the data originating from a source machine that is connected to the network; and

forwarding data to an end machine that is operating in the same host.

24. The method of claim 21, wherein the managed forwarding element operates in a host, the method further comprising:

receiving data from an end machine that is operating in the same host; and

forwarding data to the network towards a destination of the data that is connected to the network.

25. For a first network controller that pushes flow entries to a managed forwarding element in order to configure the managed forwarding element to forward data in a network, the method for pushing flow entries comprising:

receiving a set of flow entries from a second controller that generates flow entries;

processing the received set of flow entries;

based on certain criteria, determining whether the set of flow entries should be pushed to the managed forwarding element immediately;

when it is determined that the set of flow entries should be pushed to the managed forwarding element immediately, pushing each flow entry of the set of flow entries to the managed forwarding element as soon as the flow entry is processed; and

when it is determined that the set of flow entries do not have to be pushed to the managed forwarding element immediately, pushing the set of flow entries to the managed forwarding element only after processing all of the flow entries of the set of flow entries.

26. The method of claim 25 further comprising:

when it is determined the set of flow entries should be pushed to the managed forwarding element immediately, receiving flow entries computed by the managed forwarding element in response to receiving the flow entries that the managed forwarding element receives from the first network controller; and

generating a set of flow entries from the set of flow entries computed by the managed forwarding element in order to send the generated flow entries to the managed forwarding element.

27. The method of claim 25, wherein the set of flow entries comprises an indicator that indicates that, when received by the managed forwarding element, all of the flow entries of the set of flow entries have been received by the managed forwarding element.