Balancing of Forwarding and Address Resolution in Overlay Networks

• US 20130227108A1
• Filed: 02/22/2013
• Published: 08/29/2013
• Est. Priority Date: 02/24/2012
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Dunbar, Linda, Qu, XiaoRong
• Granted Patent: US 9,426,068 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: H04L 12/46 Interconnection of networks
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 2101/618 Details of network addresses
• 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 45/64 using an overlay routing layer
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering

Abstract

A network node comprising a processor configured to maintain a plurality of mapping entries for one or more virtual network instances, receive a data packet within a first virtual network instance, wherein the data packet comprises an inner destination address, match the inner destination address with one of the mapping entries, obtain an outer destination address that corresponds to the matched mapping entry, encapsulate the data packet with the outer destination address, and forward the encapsulated data packet based on the outer destination address, wherein the mapping entries maps out all of the addresses for a plurality of end nodes that participate in the first virtual network instance.

Claims

1. A network node comprising:

a processor configured to;

maintain a plurality of mapping entries for one or more virtual network instances;

receive a data packet within a first virtual network instance, wherein the data packet comprises an inner destination address;

match the inner destination address with one of the mapping entries;

obtain an outer destination address that corresponds to the matched mapping entry;

encapsulate the data packet with the outer destination address; and

forward the encapsulated data packet based on the outer destination address,

wherein the mapping entries maps out all of the addresses for a plurality of end nodes that participate in the first virtual network instance.

2. The network node of claim 1, wherein the processor is further configured to advertise a capability to provide a directory service or a forwarding service for one or more virtual network instances.

3. The network node of claim 2, wherein the processor is further configured to receive the mapping request message from a first node for the inner destination address within a group of virtual network instances maintained by the network node and forward a mapping of the inner destination address and the outer destination address requested by the mapping request message to the first node.

4. The network node of claim 1, wherein the processor is further configured to advertise a plurality of virtual network instances that the network node maintains mapping entries for.

5. The network node of claim 1, wherein the processor is further configured to advertise a connectivity status for a plurality of connections, wherein the connections couple the network node to some of the end nodes.

6. The network node of claim 1, wherein the processor is further configured to receive the plurality of mapping entries from a node.

7. The network node of claim 1, wherein the addresses for the plurality of end nodes that participate in the first virtual network instance are mapped to a plurality of boundary nodes configured to communicate with the first virtual network instance and an underlay network.

8. The network node of claim 1, wherein the processor is further configured to advertise a forwarding capability for one or more virtual network instances.

9. The network node of claim 1, wherein the first virtual network instance comprises a plurality of end nodes, and wherein the processor is further configured to maintain the mapping entries for all of the end nodes in the first virtual network instance when a number of end nodes in the virtual network instance that are directly connected to the network node exceeds a threshold value.

10. The network node of claim 9, wherein the processor is further configured to delete the mapping entries for the first virtual network instance when a second node has agreed to maintain the mapping entries for the first virtual network instance, and wherein the processor is further configured to not maintain mapping entries for end nodes in the first virtual network instance when the number of end nodes in the virtual network instance that are directly connected to the network node is under a certain threshold value.

11. The network node of claim 1, wherein the processor is further configured to prioritize the virtual network instances that have mapping entries maintained by the network node.

12. A network node comprising:

a processor configured to;

maintain a plurality of mapping entries for a set of virtual network instances;

receive a connection status message associated with a first virtual network instance;

determine whether the first virtual network instance is found within the set of virtual network instances; and

update the mapping entries when the first virtual network instance is found within the set of virtual network instances,

wherein the connection status message indicates the status of connections within the first virtual network instances, and

wherein the mapping entries maps out all of the addresses for a plurality of end nodes that participate in the first virtual network instance.

13. The network node of claim 12, wherein the connection status message is a link-state advertisement, and wherein the processor is further configured to discard the connection status message when the first virtual network instance is not found within the set of virtual network instances.

14. The network node of claim 12, wherein the processor is further configured to advertise the set of virtual network instances and the ability to provide the mapping entries to other nodes and advertise a forwarding capability for the set of virtual network instances.

15. The network node of claim 14, wherein the processor is further configured to:

receive a mapping request message within the first virtual network instance, wherein the mapping request comprises an target destination address in a virtual network instance;

map the target destination address to a boundary node address to which the target is attached; and

transmit the boundary node address,

wherein the boundary node address represents a boundary node that participates in the first virtual network instance.

16. The network node of claim 12, wherein the mapping entries comprise a plurality of either flat or fragmented addresses that correspond to a plurality of nodes that participate in the set of virtual network instances, and wherein the plurality of nodes represents all of the nodes that participate in the set of virtual network instances.

17. A method for maintaining a plurality of mapping entries for one or more virtual network instances within a node, wherein the method comprises:

sending a first message that requests the node be removed as a first designated directory node for a first virtual network instance;

determining whether a first reply message was received from a second designated directory node for the first virtual network instance;

deleting the mapping entries for the first virtual network instances when the reply message is received; and

sending an announcement message that comprises a second virtual network instances when the node is selected as the designated directory node,

wherein the reply message indicates that a second designated directory node participating in the first virtual network instance will maintain the mapping entries for the first virtual network instance, and

wherein the mapping entries for the first virtual network instance provides a plurality of boundary node addresses associated with a plurality of end node addresses that participate in the first virtual network instance.

18. The method of claim 17 further comprising:

sending a second message that requests a boundary node to take over as a second designated directory node;

receiving a second reply message; and

either sending the mapping entries for the first virtual network instance to the boundary node or requesting the boundary node to get mapping entries from a directory service.

19. The method of claim 17, wherein the first virtual network instance has a lower priority value than a second virtual network instance maintained by the node, and wherein the priority level value for the first virtual network instance is calculated based on a forwarding capacity of the node.

20. The method of claim 17 further comprising forwarding a data packet to the second designated node within the first network instance when the mapping entries for the first virtual network instances have been deleted.