Network system, layer 3 communication device, layer 2 communication device, and route selection method

• US 7,983,190 B2
• Filed: 09/15/2005
• Issued: 07/19/2011
• Est. Priority Date: 03/15/2005
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Hirota, Masaki
• Primary Examiner(s): Moe; Aung S
• Assistant Examiner(s): RIYAMI, ABDULLA A
• Application Number:
  US11/226,406
• Publication Number:
  US 20060209895A1
• Time in Patent Office: 2,133 Days
• Field of Search: 370/254, 370/252, 370/400, 370/469, 370/392, 370/401, 370/352, 370/216, 370/389, 370/256, 370/419, 370/395.53, 370/218, 370/219, 370/222, 370/224, 370/225, 370/404, 370/408, 370/475, 709/226, 709/238, 709/230, 709/236, 709/242, 709/249, 379/112.04
• US Class Current: 370/254
• 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 45/28 using route fault recovery
• CPC Class Codes: H04L 49/602 Multilayer or multiprotocol switching, e.g. IP switching

Abstract

In a layer 2 communication device included in multiple layer 2 networks, an identifying unit identifies a layer 3 control packet from among packets passing through, and an embedding unit embeds routing control information for the layer 2 network in the layer 3 control packet. In a layer 3 communication device connected to the multiple layer 2 networks, a selecting unit selects from the multiple layer 2 networks, an optimum L2 network, that is a layer 2 network forming an optimum communication route, based on a communication destination, and a setting unit sets a packet to be transmitted to the optimum L2 network.

Claims

1. A network system comprising:

a plurality of layer 2 communication devices that constitute a plurality of layer 2 networks that have loop configurations with blocks positioned differently; and

a layer 3 communication device that performs communication through the plurality of layer 2 networks without communicating through the blocks, wherein

each of the layer 2 communication devices includes

an identifying unit to identify an Open Shortest Path First (OSPF) packet or a Routing Information Protocol (RIP) packet from among packets passing through the layer 2 communication device; and

an embedding unit to embed routing control information for a layer 2 network in the OSPF packet or the RIP packet, and

the layer 3 communication device includes

a selecting unit to select, from the plurality of layer 2 networks that have the loop configurations with the blocks positioned differently, an optimum layer 2 network based on the routing control information for the layer 2 network embedded in the OSPF packet or the RIP packet; and

a setting unit to set a packet to be transmitted to the optimum layer 2 network.

2. The network system according to claim 1, wherein the layer 3 communication device further includes

a replicating unit to replicate the OSPF packet or the RIP packet by a number of the plurality of layer 2 networks that have the loop configurations with the blocks positioned differently, if the OSPF packet or the RIP packet is to be transmitted over the plurality of layer 2 networks.

3. A layer 3 communication device connected to a plurality of layer 2 networks that have loop configurations with blocks positioned differently, comprising:

a selecting unit to select, from the plurality of layer 2 networks that have loop configurations with blocks positioned differently, an optimum layer 2 network based on routing control information for a layer 2 network embedded in an Open Shortest Path First (OSPF) packet or a Routing Information Protocol (RIP) packet by a layer 2 communication device; and

a setting unit to set a packet to be transmitted to the optimum layer 2 network.

4. The layer 3 communication device according to claim 3, further comprising:

an analyzing unit to receive a layer 2 control packet, and analyzes a state of multiplicity of the layer 2 networks, based on information in the layer 2 control packet received.

5. A route selecting method for a network system that includes a plurality of layer 2 communication devices that constitute a plurality of layer 2 networks that have loop configurations with blocks positioned differently, and a layer 3 communication device that performs communication through the plurality of layer 2 networks without communicating through the blocks, the method comprising:

identifying, performed by the layer 2 communication device, an Open Shortest Path First (OSPF) packet or a Routing Information Protocol (RIP) packet from among packets passing through the layer 2 communication device;

embedding, performed by the layer 2 communication device, routing control information for a layer 2 network in the OSPF packet or the RIP packet; and

selecting, performed by the layer 3 communication device, from the plurality of layer 2 networks that have the loop configurations with the blocks positioned differently, an optimum layer 2 network based on the routing control information for the layer 2 network embedded in the OSPF packet or the RIP packet.

6. A layer 2 communication device comprising:

an identifying unit to identify an Open Shortest Path First (OSPF) packet or a Routing Information Protocol (RIP) packet from among packets passing through the layer 2 communication device that constitutes a plurality of layer 2 networks that have loop configurations with blocks positioned differently; and

an embedding unit to embed routing control information for a layer 2 network in the OSPF packet or the RIP packet, the routing control information enables the selecting, from the plurality of layer 2 networks, an optimum layer 2 network by a layer 3 communication device.