Method and System for Preventing Loops in Mesh Networks

• US 20130100872A1
• Filed: 10/25/2011
• Published: 04/25/2013
• Est. Priority Date: 10/25/2011
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Aruba Networks Incorporated (Hewlett-Packard Enterprise Company)
• Inventors: Zou, Xu, Huang, Kangchang, Liu, Yan
• Granted Patent: US 9,060,322 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/18 Loop-free operations
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing

Abstract

The present disclosure discloses a network device and/or method for preventing loops in routing paths of network frames in a wireless digital network. The disclosed network device at a network node receives a frame from a wired network. The frame includes a site identifier uniquely corresponding to the wired network, a source physical address, and a destination physical address. If the network node is selected as a representative portal node, the network device forwards the frame. Otherwise, if another network node is selected as the representative portal node, the network device drops the received frame to prevent forming a loop in a routing path corresponding to the frame. If not other network is selected as the representative portal node, the network device floods the frame to other network nodes in the wireless network.

Claims

1. A method comprising:

receiving, at a network device at a first network node in a wireless network, a frame from a wired network, wherein the frame comprises a site identifier uniquely corresponding to the wired network and a destination physical address;

determining, by the network device, whether the network node is selected as a representative portal node based on the site identifier and the destination physical address; and

responsive to the first network node being selected as the representative portal node, forwarding, by the network device, the frame to a second network node.

2. The method of claim 1, further comprising:

responsive to the first network node not being selected as the representative portal node, determining, by the network device, whether any other network node in the wireless network is selected as the representative portal node based on the site identifier and the destination physical address; and

responsive to a third network node being selected as the representative portal node, dropping, by the network device, the received frame to prevent forming a loop in a routing path corresponding to the frame.

3. The method of claim 2, further comprising:

responsive to no other network node in the wireless network being selected as the representative portal node, determining whether the destination physical address exist in a forwarding table at the first network node;

responsive to the destination physical address existing in the forwarding table, transmitting, by the network device, the frame to a fourth network node at a forwarding address corresponding to the destination physical address in the forwarding table; and

responsive to the destination physical address not existing in the forwarding table, transmitting, by the network device, the frame to one or more other network nodes in the wireless network.

4. The method of claim 2, wherein determining whether any other network node in the wireless network is selected as the representative portal node based on the site identifier and the destination physical address further comprises:

identifying, by the network device, one or more other network nodes which are portal nodes associated with the wired network from which the frame is received;

sending, by the network device, an inquiry comprising the site identifier and the destination physical address;

receiving, by the network device, a response from the one or more other network nodes; and

determining, by the network device, whether any of the one or more other network nodes is selected as the representative portal node based on the response.

5. The method of claim 1, further comprises:

determining whether the destination physical address indicates that the frame is a multicast frame; and

responsive to the destination physical address indicating that the frame is the multicast frame, multicasting the frame to a group of network nodes based on the destination physical address.

6. The method of claim 1, wherein the frame further comprises a source physical address, and wherein the method further comprises:

determining, by the network device, whether the source physical address is associated with any previously received frame; and

responsive to the source physical address not being associated with any previously received frame, dropping, by the network device, the frame.

7. The method of claim 6, further comprising:

storing, by the network device, the source physical address at the first network node;

determining, by the network device, whether the source physical address is known to any portal node associated with the site identifier;

responsive to the source physical address being known to a portal node, associating the source physical address with the portal node associated with the site identifier in a forwarding table at the first network node; and

responsive to the source physical address being known to no portal node, associating the source physical address with the first network node in the forwarding table at the first network node.

8. A network device comprising:

a processor;

a memory;

a receiving mechanism coupled to the processor, at a first network node in a wireless network, the receiving mechanism to receive a frame from a wired network, wherein the frame comprises a site identifier uniquely corresponding to the wired network and a destination physical address;

a determining mechanism coupled to the processor, the determining mechanism to determine whether the network node is selected as a representative portal node based on the site identifier and the destination physical address; and

a frame handling mechanism coupled to the processor, the frame handling mechanism to forward, in response to the first network node being selected as the representative portal node, the frame to a second network node.

9. The network device of claim 8,

wherein the determine mechanism further to determine, in response to the first network node not being selected as the representative portal node, whether any other network node in the wireless network is selected as the representative portal node based on the site identifier and the destination physical address;

and

wherein the frame handling mechanism further to drop, in response to a third network node being selected as the representative portal node, the received frame to prevent forming a loop in a routing path corresponding to the frame.

10. The network device of claim 9, further comprising:

wherein the determining mechanism further to determine, in response to no other network node in the wireless network being selected as the representative portal node, whether the destination physical address exist in a forwarding table at the first network node;

wherein the frame handling mechanism further to transmit, in response to the destination physical address existing in the forwarding table, the frame to a fourth network node at a forwarding address corresponding to the destination physical address in the forwarding table; and

wherein the frame handling mechanism further to transmit, in response to the destination physical address not existing in the forwarding table, the frame to one or more other network nodes in the wireless network.

11. The network device of claim 9, wherein the determining mechanism further to:

identify one or more other network nodes which are portal nodes associated with the wired network from which the frame is received;

send an inquiry comprising the site identifier and the destination physical address;

receive a response from the one or more other network nodes; and

determine whether any of the one or more other network nodes is selected as the representative portal node based on the response.

12. The network device of claim 8,

wherein the determining mechanism further determines whether the destination physical address indicates that the frame is a multicast frame;

and

wherein the frame handling mechanism multicasts the frame to a group of network nodes based on the destination physical address in response to the destination physical address indicating that the frame is the multicast frame.

13. The network device of claim 8,

wherein the frame further comprises a source physical address;

wherein the determining mechanism further to determine whether the source physical address is associated with any previously received frame; and

wherein the frame handling mechanism further to drop the frame in response to the source physical address not being associated with any previously received frame.

14. The network device of claim 13, further comprising:

a storing mechanism coupled to the processor, the storing mechanism to store the source physical address at the first network node;

wherein the determining mechanism further determines whether the source physical address is known to any portal node associated with the site identifier;

wherein the storing mechanism associates, in response to the source physical address being known to a portal node, the source physical address with the portal node associated with the site identifier in a forwarding table at the first network node; and

wherein the storing mechanism associates, in response to the source physical address being known to no portal node, the source physical address with the first network node in the forwarding table at the first network node.

15. A non-transitory computer-readable storage medium storing embedded instructions that are executed by one or more mechanisms implemented within a network device to perform a plurality of operations comprising:

receiving, at a first network node in a wireless network, a frame from a wired network, wherein the frame comprises a site identifier uniquely corresponding to the wired network and a destination physical address;

determining whether the network node is selected as a representative portal node based on the site identifier and the destination physical address; and

forwarding, in response to the first network node being selected as the representative portal node, the frame to a second network node.

16. The non-transitory computer-readable storage medium of claim 15, wherein the plurality of operations further comprises:

determining whether any other network node in the wireless network is selected as the representative portal node based on the site identifier and the destination physical address in response to the first network node not being selected as the representative portal node; and

dropping the received frame to prevent forming a loop in a routing path corresponding to the frame in response to a third network node being selected as the representative portal node.

17. The non-transitory computer-readable storage medium of claim 16, wherein the plurality of operations further comprises:

determining whether the destination physical address exist in a forwarding table at the first network node in response to no other network node in the wireless network being selected as the representative portal node;

transmitting the frame to a fourth network node at a forwarding address corresponding to the destination physical address in the forwarding table in response to the destination physical address existing in the forwarding table; and

transmitting the frame to one or more other network nodes in the wireless network in response to the destination physical address not existing in the forwarding table.

18. The non-transitory computer-readable storage medium of claim 16, wherein determining whether any other network node in the wireless network is selected as the representative portal node based on the site identifier and the destination physical address further comprises:

identifying, by the network device, one or more other network nodes which are portal nodes associated with the wired network from which the frame is received;

sending, by the network device, an inquiry comprising the site identifier and the destination physical address;

receiving, by the network device, a response from the one or more other network nodes; and

determining, by the network device, whether any of the one or more other network nodes is selected as the representative portal node based on the response.

19. The non-transitory computer-readable storage medium of claim 15, wherein the plurality of operations further comprises:

determining whether the destination physical address indicates that the frame is a multicast frame; and

multicasting the frame to a group of network nodes based on the destination physical address in response to the destination physical address indicating that the frame is the multicast frame.

20. The non-transitory computer-readable storage medium of claim 15, wherein the frame further comprises a source physical address, and wherein the plurality of operations further comprises:

determining whether the source physical address is associated with any previously received frame; and

dropping the frame in response to the source physical address not being associated with any previously received frame.

21. The non-transitory computer-readable storage medium of claim 20, wherein the plurality of operations further comprises:

storing the source physical address at the first network node;

determining whether the source physical address is known to any portal node associated with the site identifier;

associating the source physical address with the portal node associated with the site identifier in a forwarding table at the first network node in response to the source physical address being known to a portal node; and

associating the source physical address with the first network node in the forwarding table at the first network node in response to the source physical address being known to no portal node.