# US 2001/0025318 A1 · Apparatus and method for configuring spanning tree and spanning tree protocol system and bridge system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2001/0025318 A1 - Document ID: US20010025318A1 - Status: Published application - Kind: A1 - Application number: 09/805,276 - Filed: 2001-03-13 - Published: 2001-09-27 - Earliest claimed: 2000-03-17 - Assignees: Anritsu Corporation - Inventors: Mitsuru Higashiyama - Web page: https://patentgrep.com/patent/US20010025318A1 ## CPC - H04L 45/48: Routing tree calculation - H04L 12/462: {LAN interconnection over a bridge based backbone} - 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)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract An apparatus for configuring a spanning tree is used for a network in which a plurality of virtual LANs coexist. This apparatus for configuring the spanning tree has at least one bridge and a holding section. The above at least one bridge has a plurality of ports, and is capable of configuring a plurality of virtual LANs by logically combining the plurality of ports. The holding section holds on the bridge for each of the plurality of virtual LANs, information that is a combination between a code for identifying each of the plurality of virtual LANs configured by the bridge and a code for identifying a root bridge in the spanning tree for each of the plurality of virtual LANs. ## Claims ### Claim 1 An apparatus for configuring a spanning tree used for a network in which a plurality of virtual LANs coexist comprising: at least one bridge having a plurality of ports, the bridge capable of configuring a plurality of virtual LANs by logically combining the plurality of ports; and holding means for holding on the bridge by each of the plurality of virtual LANs, information that is a combination between a code for identifying each of the plurality of virtual LANs configured by the bridge and a code for identifying a root bridge in a spanning tree for each of the plurality of virtual LANs. ### Claim 2 (depends on 1) An apparatus according to claim 1, wherein the holding means is provided by the number of virtual LANs in the device as a VLAN-ID for each of the plurality of virtual LANs that is information to be held in the bridge and as a spanning tree protocol instance that is a database containing an MAC address of a root bridge in the plurality of virtual LANs. ### Claim 3 (depends on 1) An apparatus according to claim 1, further comprising: means for discriminating whether or not Configuration Bridge Protocol Data Units (hereinafter, referred to as BPDUs) that the bridge receives bundle BPDUs corresponding to a plurality of VLANs in one packet, and releasing the bundled BPDUs for each VLAN; means for processing a spanning tree by instance of each VLAN based on the BPDU, thereby updating the instance; and means for discriminating whether or not a BPDU outputted after updating the instance is a BPDU relevant to a trunk port, and when the BPDU is the BPDU relevant to trunk port, bundling a plurality of BPDUs in one packet, and outputting them. ### Claim 4 A method for configuring a spanning tree used for a network in which a plurality of virtual LANs coexist, the method comprising the steps of: providing at least one bridge having a plurality of ports, the bridge being capable of configuring a plurality of virtual LANs by logically combining the plurality of ports; and holding on the bridge for each of the plurality of virtual LANs, information that is a combination between a code for identifying each of the plurality of virtual LANs configured by the bridge and a code for identifying a root bridge in a spanning tree for each of the plurality of virtual LANs. ### Claim 5 An apparatus for configuring a spanning tree used for a network in which a plurality of virtual LANs coexist, the apparatus comprising: at least two bridges each having a plurality of ports, the bridges each being capable of configuring a plurality of virtual LANs by logically combining the plurality of ports; holding means for holding on the bridge for each of the plurality of virtual LANs, information that is a combination between a code for identifying each of the plurality of virtual LANs configured by the bridge and a code for identifying a root bridge in a spanning tree for each of the plurality of virtual LANs; output means for, when there is outputted plural items of spanning tree configuration information containing a code in which one of the bridges identifies a root bridge for each of the plurality of virtual LANs, bundling in one packet at least two items of spanning tree configuration information contained in the plurality of spanning tree configuration information and outputting them; and control means for acquiring the spanning tree configuration information on each of the plurality of virtual LANs from the packet in a bridge which receives the packet, thereby controlling opening and closing of each of the plurality of ports that the bridge has for each of the plurality of virtual LANs. ### Claim 6 (depends on 5) An apparatus according to claim 5, wherein the holding means is provided by the number of virtual LANs in the apparatus as a spanning tree protocol instance that is a database containing a VLAN-ID of each of the plurality of virtual LANs that is information to be held on the bridge and an MAC address of a root bridge in the plurality of virtual LANs. ### Claim 7 (depends on 6) An apparatus according to claim 6, further comprising: means for discriminating whether or not BPDUs that the bridge receives are bundled BPDUs that correspond to a plurality of VLANs in one packet, and releasing the bundled BPDUs for each VLAN; means for processing spanning tree by instance for each VLAN based on the BPDU, and updating the instance; and means for discriminating whether or not a BPDU to be outputted after updating the instance is a BPDU relevant to a trunk port, and, when the BPDU is the BPDU relevant to the trunk port, bundling a plurality of BPDUs in one packet, and outputting them. ### Claim 8 A method for configuring a spanning tree used for a network in which a plurality of virtual LANs coexist, the method comprising the steps of: providing at least two bridges each having a plurality of ports, the bridges each being capable of configuring a plurality of virtual LANs by logically combining the plurality of ports; holding on the bridge for each of the plurality of virtual LANs, information that is a combination between a code for identifying each of the plurality of virtual LANs configured by the bridge and a code for identifying a root bridge in a spanning tree for each of the plurality of virtual LANs; when there is outputted plural items of spanning tree configuration information containing a code in which one of the bridges identifies a root bridge for each of the plurality of virtual LANs, bundling in one packet at least two items of spanning tree configuration information contained in the plurality of spanning tree configuration information and outputting them; and acquiring the spanning tree configuration information on each of the plurality of virtual LANs from the packet in a bridge which receives the packet, thereby controlling opening and closing of each of the plurality of ports that the bridge has for each of the plurality of virtual LANs. ### Claim 9 A spanning tree protocol system, comprising: a network in which a plurality of VLANs coexist and a spanning tree protocol is applied; and a spanning tree protocol instance having a database containing a VLAN-ID of at least the VLAN in the plurality of VLANs and an MAC address of a root bridge in the VLAN for each of the plurality of VLANs. ### Claim 10 A bridge system used for a network in which there exists a plurality of VLANs to which a spanning protocol is applied, the bridge system comprising: at least one bridge having a plurality of ports, the bridge being capable of configuring a plurality of virtual LANs by logically combining the plurality of ports; and a spanning tree protocol instance having a database containing a VLAN-ID of at least the VLAN of the plurality of VLANs and an MAC address of a root bridge in the VLAN for each of the plurality of VLANs. ### Claim 11 A bridge system used for a network in which there exists a plurality of VLANs to which a spanning tree protocol is applied, the bridge system comprising: at least two bridges each having a plurality of ports, the bridges each being capable of configuring a plurality of virtual LANs by logically combining the plurality of ports; a spanning tree protocol instance having a VLAN-ID of at least the VLAN of the plurality of VLANs and an MAC address of a root bridge in the VLAN for each of the plurality of VLANs; output means for, when one of the bridges outputs plural items of spanning tree configuration information containing a code for identifying a root bridge for each of the plurality of virtual LANs, bundling in one packet at least two items of spanning configuration information contained in the plural items of spanning tree configuration information and outputting them; and control means for acquiring the spanning tree configuration information on each of the plurality of virtual LANs from the packet in a bridge which receives the packet, thereby controlling opening and closing of each of the plurality of ports that the bridge has for each of the plurality of virtual LANs.