# US 11,115,285 B2 · Device detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,285 B2 - Document ID: US11115285B2 - Status: Granted - Kind: B2 - Application number: 16/303,955 - Filed: 2017-07-17 - Published: 2020-10-08 - Granted: 2021-09-07 - Earliest claimed: 2016-07-28 - Assignees: New H3C Technologies Co., Ltd. - Applicants: New H3C Technologies Co., Ltd. - Inventors: Weifeng Wang - Web page: https://patentgrep.com/patent/US11115285B2 ## CPC - 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 12/12: Arrangements for remote connection or disconnection of substations or of equipment thereof - H04L 41/0816: the condition being an adaptation, e.g. in response to network events - H04L 41/0895: Configuration of virtualised networks or elements, e.g. virtualised network function or OpenFlow elements - Y02D 30/50: in wire-line communication networks, e.g. low power modes or reduced link rate - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A Software Defined Network (SDN) controller receives a detecting packet reported by a first switch and initiated by a first device. The SDN controller sends, for each of switches having an SDN connection with the SDN controller, the detecting packet and information of all downlink ports of the switch to the switch in a way that the switch is capable of sending the detecting packet through the downlink port. The SDN controller receives a response packet which is sent by a second switch and initially generated by a second device in response to receiving the detecting packet from the second switch, wherein an IP address of the second device matches a destination IP address of the detecting packet. The SDN controller sends forwarding configuration information to the second switch in a way that the second switch is capable of configuring a port through which the response packet is received. ## Claims ### Claim 1 A method of detecting a device, comprising: receiving, by a Software Defined Network (SDN) controller, a detecting packet which is sent by a first switch and initiated by a first device accessing the first switch, wherein the detecting packet carries an identifier of a Virtual Local Area Network (VLAN) to which the first device belongs; sending, by the SDN controller, for each of switches having an SDN connection with the SDN controller, the detecting packet and information of all downlink ports of the switch having an SDN connection with the SDN controller to the switch having an SDN connection with the SDN controller in a way that the switch having an SDN connection with the SDN controller sends the detecting packet through the downlink port without checking whether the identifier of the VLAN carried in the detecting packet matches an identifier of Permit VLAN configured on the downlink port; receiving, by the SDN controller, a response packet which is sent by a second switch, wherein the response packet is sent by a second device to the second switch accessing the second switch in response to receiving the detecting packet, wherein an Internet Protocol (IP) address of the second device matches a destination IP address of the detecting packet; and sending, by the SDN controller, forwarding configuration information to the second switch in a way that the second switch configures a port through which the response packet is received. ### Claim 2 (depends on 1) The method according to claim 1, wherein the information of the downlink ports sent to the first switch excludes information of the port through which the first switch receives the detecting packet. ### Claim 3 (depends on 1) The method according to claim 1, wherein the response packet carries an identifier of a VLAN to which the second device belongs. ### Claim 4 (depends on 3) The method according to claim 3, wherein the forwarding configuration information comprises an identifier of a Permit VLAN and mapping information between the Permit VLAN and Virtual Extensible Local Area Network (VXLAN), the identifier of the Permit VLAN indicates the VLAN to which the second device belongs. ### Claim 5 (depends on 1) The method according to claim 1, wherein the detecting packet is an Address Resolution Protocol (ARP) request packet, and the response packet is an ARP response packet. ### Claim 6 A Software Defined Network (SDN) controller, comprising: a processor; and a non-transitory machine-readable storage medium to store machine-executable instructions which are executable by the processor to: receive a detecting packet which is sent by a first switch and initiated by a first device accessing the first switch, wherein the detecting packet carries an identifier of a Virtual Local Area Network (VLAN) to which the first device belongs; send, for each of switches having an SDN connection with the SDN controller, the detecting packet and information of all downlink ports of the switch having an SDN connection with the SDN controller to the switch having an SDN connection with the SDN controller in a way that the switch having an SDN connection with the SDN controller sends the detecting packet through the downlink port without checking whether the identifier of the VLAN carried in the detecting packet matches an identifier of Permit VLAN configured on the downlink port; receive a response packet which is sent by a second switch, wherein the response packet is sent by a second device accessing the second switch to the second switch in response to receiving the detecting packet, wherein an Internet Protocol (IP) address of the second device matches a destination IP address of the detecting packet; and send forwarding configuration information to the second switch in a way that the second switch configures a port through which the response packet is received. ### Claim 7 (depends on 6) The SDN controller according to claim 6, wherein, the information of the downlink ports sent to the first switch excludes information of the port through which the first switch receives the detecting packet. ### Claim 8 (depends on 6) The SDN controller according to claim 6, wherein, the response packet carries an identifier of a VLAN to which the second device belongs. ### Claim 9 (depends on 8) The SDN controller according to claim 8, wherein the forwarding configuration information comprises an identifier of Permit VLAN and mapping information between the Permit VLAN and Virtual Extensible Local Area Network (VXLAN), the identifier of the Permit VLAN indicates the VLAN to which the second device belongs. ### Claim 10 (depends on 6) The SDN controller according to claim 6, wherein, the detecting packet is an Address Resolution Protocol (ARP) request packet, and the response packet is an ARP response packet. ### Claim 11 A non-transitory machine-readable storage medium storing machine executable instructions which are invoked and executed by the processor to: receive a detecting packet which is sent by a first switch and initiated by a first device accessing the first switch, wherein the detecting packet carries an identifier of a Virtual Local Area Network (VLAN) to which the first device belongs; send, for each of switches having an Software Defined Network (SDN) connection with the SDN controller, the detecting packet and information of all downlink ports of the switch having an SDN connection with the SDN controller to the switch having an SDN connection with the SDN controller in a way that the switch sends the detecting packet through the downlink port without checking whether the identifier of the VLAN carried in the detecting packet matches an identifier of Permit VLAN configured on the downlink port; receive a response packet which is sent by a second switch, wherein the response packet is sent by a second device accessing the second switch to the second switch in response to receiving the detecting packet, wherein an Internet Protocol (IP) address of the second device matches a destination IP address of the detecting packet; and send forwarding configuration information to the second switch in a way that the second switch configures a port through which the response packet is received. ### Claim 12 (depends on 11) The non-transitory machine-readable storage medium according to claim 11, wherein, the response packet carries an identifier of a VLAN to which the second device belongs. ### Claim 13 (depends on 12) The non-transitory machine-readable storage medium according to claim 12, wherein, the forwarding configuration information comprises an identifier of Permit VLAN and mapping information between the Permit VLAN and Virtual Extensible Local Area Network (VXLAN); the identifier of the Permit VLAN indicates the VLAN to which the second device belongs.