Network apparatus enabling roaming across subnets

• US 8,503,396 B2
• Filed: 08/04/2011
• Issued: 08/06/2013
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Blanchette, Richard H., Bouchard, Martin, Gupta, Anil, Koehler, Yannick, Moineau, Gilbert, Sands, Roger D., Trudeau, Pierre, Mouveaux, Frderic D.
• Primary Examiner(s): Edouard, Patrick N.
• Assistant Examiner(s): PHAM, TIMOTHY X
• Application Number:
  US13/198,084
• Publication Number:
  US 20120039230A1
• Time in Patent Office: 733 Days
• Field of Search: 370/312, 370/328
• US Class Current: 370/331
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's
• CPC Class Codes: H04W 40/36 due to handover
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 80/02 Data link layer protocols
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

To enable a network apparatus to detect L3 roaming users and to take appropriate forwarding actions, L3 knowledge is introduced inside an L2 bridge forwarding table in the network apparatus. As a client moves from a subnet associated with a first network element to a subnet associated with the network apparatus, a determination is made regarding whether the client is roaming by evaluating a source IP address within a L3 packet header within a first frame received at the network apparatus. If, as a result of the evaluating step, it is determined that the client is roaming, the L2 bridge forwarding table is configured to include a source MAC address of the client together with information identifying a destination interface for use in directing client data traffic back towards the subnet associated with the first network element.

Claims

1. A network apparatus comprising:

a data storage to store a layer 2 (L2) bridge forwarding table; and

a processor to configure the L2 bridge forwarding table, wherein when a client is determined to be moving from a subnet associated with a first network element to a subnet associated with the network apparatus, evaluating a source Internet Protocol (IP) address within a Layer 3 (L3) header in a first frame to determine if the client is roaming, and when the client is determined to be roaming, the processor is to configure the L2 bridge forwarding table to include a source Medium Access Control (MAC) address of the client together with information identifying an interface for use in directing client data traffic back towards the subnet associated with the first network element,

wherein an encapsulation tunnel is associated with the first network element and the network apparatus prior to the client moving from the subnet associated with the first network.

2. The network apparatus of claim 1, wherein the processor is to direct the client data traffic in the first frame towards the subnet associated with the first network element via the interface associated with the source MAC address.

3. The network apparatus of claim 1, wherein the client data traffic is tunneled from the network apparatus to the first network element via the encapsulation tunnel.

4. The network apparatus of claim 3, wherein the encapsulation tunnel is a Generic Rounding Encapsulation (GRE) encapsulation tunnel.

5. The network apparatus of claim 1, wherein the network apparatus is a service controller.

6. The network apparatus of claim 1, wherein the network apparatus is a bridge.

7. The network apparatus of claim 1, wherein the L2 bridge forwarding table also includes information identifying at least a source interface for use in receiving data traffic returned towards the subnet associated with the network apparatus.

8. The network apparatus of claim 1, wherein IP address information of the client stored at the network apparatus is used to enable the client to receive inbound data, and the inbound data is one of a unicast, a multicast and a broadcast.

9. The network apparatus of claim 8, wherein receipt of the multicast or broadcast data is enabled via exchange of given messages between the first network element and the network apparatus, where the given messages are delivered over a secure tunnel, a non-secure tunnel, or without using a tunnel.

10. The network apparatus of claim 8, wherein the processor is to enable receipt of the unicast data by configuring the L2 bridge forwarding table.

11. The network apparatus of claim 1, wherein the inbound data is received at the client prior to transmission of the first frame by the client or the forwarding of the first frame after configuration of the L2 bridge forwarding table.

12. The network apparatus of claim 1, wherein the processor is to direct the client data traffic in any frame after the first frame towards the subnet associated with the first network element via the interface associated with the source MAC address.

13. The network apparatus of claim 1, wherein the client data traffic is associated with one of unicast traffic, multicast traffic, broadcast traffic, an ARP data packet, and a DHCP renew packet.

14. A network apparatus comprising:

a plurality of interfaces; and

a bridge interface connected to the plurality of interfaces and to access an layer 2 (L2) forwarding table to identify an interface of the plurality of interfaces to send data in a network,

wherein when a client is determined to be moving from a subnet associated with a first network element to a subnet associated with the network apparatus by evaluating a source Internet Protocol (IP) address within a Layer 3 (L3) header in a first frame to determine if the client is roaming, and when the client is determined to be roaming, the network apparatus is to configure the L2 bridge forwarding table to include a source Medium Access Control (MAC) address of the client together with information identifying one of the plurality of interfaces, and the bridge interface is to direct client data traffic back towards the subnet associated with the first network element through the one of the plurality of interfaces,

wherein an encapsulation tunnel is associated with the first network element and the network apparatus prior to the client moving from the subnet associated with the first network.

15. The network apparatus of claim 14, wherein the client data traffic is tunneled from the network apparatus to the first network element via the encapsulation tunnel.

16. The network apparatus of claim 14, wherein the network apparatus is a service controller.

17. The network apparatus of claim 14, wherein the network apparatus is a bridge.

18. The network apparatus of claim 14, wherein the L2 bridge forwarding table also includes information identifying a source interface of the plurality of interfaces for use in receiving data traffic returned towards the subnet associated with the network apparatus.

19. A non-transitory computer readable medium including machine readable instructions that when executed by a processor are to:

when a client is determined to be moving from a subnet associated with a first network element to a subnet associated with a second network element by evaluating a source Internet Protocol (IP) address within a Layer 3 (L3) header in a first frame to determine if the client is roaming, and when the client is determined to be roaming, configure an layer 2 (L2) bridge forwarding table in the second network element to include a source Medium Access Control (MAC) address of the client together with information identifying an interface for use in directing client data traffic back towards the subnet associated with the first network element,

wherein an encapsulation tunnel is associated with the first network element and the network apparatus prior to the client moving from the subnet associated with the first network.

20. The non-transitory compute readable medium of claim 19, wherein the method comprises directing the client data traffic in the first frame towards the subnet associated with the first network element via the interface associated with the source MAC address via the encapsulation tunnel.