# US 10,454,882 B2 · DHCP in layer-3 overlay with anycast address support and network address transparency > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,454,882 B2 - Document ID: US10454882B2 - Status: Granted - Kind: B2 - Application number: 15/638,413 - Filed: 2017-06-30 - Published: 2019-01-03 - Granted: 2019-10-22 - Earliest claimed: 2017-06-30 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Sanjay Kumar Hooda; Aniket Ghule; Vimarsh Puneet; Atri Indiresan - Web page: https://patentgrep.com/patent/US10454882B2 ## CPC - H04L 61/5014: using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP] - H04L 12/4633: {Interconnection of networks using encapsulation techniques, e.g. tunneling} - H04L 12/4645: {Details on frame tagging (routing of packets H04L45/00; support for virtual LAN H04L49/354)} - H04L 63/0272: {Virtual private networks} - H04L 63/0471: {applying encryption by an intermediary, e.g. receiving clear information at the intermediary and encrypting the received information at the intermediary before forwarding} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Address support and network address transparency may be provided. First, a border device may receive a processed network configuration parameter request having an address of a subnet to which a client device is associated and information data in an information field of the network configuration parameter request. The information data may comprise an address of a network device and an identifier of the subnet to which the client device is associated. Next, the border device may encapsulate the processed network configuration parameter request with the information data extracted from the processed network configuration parameter request. The border device may then forward the encapsulated network configuration parameter response to the network device. ## Claims ### Claim 1 A method comprising: receiving, by a relay agent on a network device, a network configuration parameter request; adding, by the relay agent to the received network configuration parameter request, an address of a subnet to which a client device is associated and information data into an information field of the network configuration parameter request, the information data comprising an address of the network device and an identifier of the subnet to which the client device is associated; forwarding, by the relay agent, the network configuration parameter request, to a network configuration server; processing, by the network configuration server, the network configuration parameter request; forwarding, by the network configuration server, the processed network configuration parameter request to a border device; encapsulating, by the border device, the processed network configuration parameter request with information data extracted from the processed network configuration parameter request, wherein encapsulating the processed network configuration parameter request comprises, extracting the information data comprising a Source-Switch-IP address and a Virtual Network Identifier (VNI) from a Dynamic Host Configuration Protocol (DHCP) option 82 field of the processed network configuration parameter request, and creating a Virtual Extensible Local Area Network (VXLAN) header for the encapsulated network configuration parameter request using the Source-Switch-IP address and the VNI extracted from the DHCP option 82 field of the processed network configuration parameter request; and forwarding, by the border device to the network device, the encapsulated network configuration parameter request encapsulated with the created VXLAN header. ### Claim 2 (depends on 1) The method of claim 1, wherein receiving the network configuration parameter request comprises receiving the network configuration parameter request from the client device. ### Claim 3 (depends on 1) The method of claim 1, wherein receiving the network configuration parameter request comprises receiving the network configuration parameter request comprising a Dynamic Host Configuration Protocol (DHCP) request. ### Claim 4 (depends on 1) The method of claim 1, wherein adding the address of the subnet comprises adding the address of the subnet comprising a Gateway IP Address (GIADDR) of the subnet. ### Claim 5 (depends on 1) The method of claim 1, wherein adding the address of the subnet comprises adding the address of the subnet wherein the subnet is a Virtual Private Network (VPN). ### Claim 6 (depends on 1) The method of claim 1, wherein adding the information data into the information field of the network configuration parameter request comprises adding the information data into the information field of the network configuration parameter request wherein the information field comprises a Dynamic Host Configuration Protocol (DHCP) option 82 field. ### Claim 7 (depends on 1) The method of claim 1, wherein adding the information data into the information field of the network configuration parameter request comprises adding the identifier of the subnet to which the client device is associated to one of the following sub-fields of a Dynamic Host Configuration Protocol (DHCP) option 82 field: a circuit ID field and a remote ID field. ### Claim 8 (depends on 1) The method of claim 1, wherein adding the information data into the information field of the network configuration parameter request comprises adding the address of the network device to one of the following sub-fields of a Dynamic Host Configuration Protocol (DHCP) option 82 field: a circuit ID field and a remote ID field. ### Claim 9 (depends on 1) The method of claim 1, wherein forwarding the configuration parameter request to the network configuration server comprises forwarding the configuration parameter request to the network configuration server comprising a Dynamic Host Configuration Protocol (DHCP) server. ### Claim 10 (depends on 1) The method of claim 1, further comprising decapsulating, by the network device, the encapsulated network configuration parameter request. ### Claim 11 A method comprising: receiving, by a border device, a processed network configuration parameter response having an address of a subnet to which a client device is associated and information data in an information field of the network configuration parameter response, the information data comprising an address of a network device and an identifier of the subnet to which the client device is associated; encapsulating, by the border device, the processed network configuration parameter response with information data extracted from the processed network configuration parameter response, wherein encapsulating the processed network configuration parameter response comprises, extracting the information data comprising a Source-Switch-IP address and a Virtual Network Identifier (VNI) from a Dynamic Host Configuration Protocol (DHCP) option 82 field of the processed network configuration parameter response, and creating a Virtual Extensible Local Area Network (VXLAN) header for the encapsulated network configuration parameter response using the Source-Switch-IP address and the VNI extracted from the DHCP option 82 field of the processed network configuration parameter response; and forwarding, by the border device to the network device, the encapsulated network configuration parameter response encapsulated with the created VXLAN header. ### Claim 12 (depends on 11) The method of claim 11, wherein receiving the processed network configuration parameter response comprises receiving the processed network configuration parameter response from a Dynamic Host Configuration Protocol (DHCP) server, the network configuration parameter response comprising a Dynamic Host Configuration Protocol (DHCP) offer. ### Claim 13 (depends on 11) The method of claim 11, wherein receiving the processed network configuration parameter response having the information data in the information field of the network configuration parameter response comprises receiving the processed network configuration parameter response having the information data in the information field wherein the information field comprises a Dynamic Host Configuration Protocol (DHCP) option 82 field. ### Claim 14 (depends on 11) The method of claim 11, wherein receiving the processed network configuration parameter response having the information data in the information field of the network configuration parameter response comprises receiving the processed network configuration parameter response having the information data in the information field wherein the information field comprises a Dynamic Host Configuration Protocol (DHCP) option 82 field wherein the identifier of the subnet to which the client device is associated is contained in one of following sub-fields of the DHCP option 82 field: a circuit ID field and a remote ID field. ### Claim 15 (depends on 11) The method of claim 11, wherein receiving the processed network configuration parameter response having the information data in the information field of the network configuration parameter response comprises receiving the processed network configuration parameter response having the information data in the information field wherein the information field comprises a Dynamic Host Configuration Protocol (DHCP) option 82 field wherein the address of the network device is contained in one of following sub-fields of the DHCP option 82 field: a circuit ID field and a remote ID field. ### Claim 16 An apparatus comprising: a memory storage; and a processing unit coupled to the memory storage, wherein the processing unit is operative to: receive a processed network configuration parameter response having an address of a subnet to which a client device is associated and information data in an information field of the network configuration parameter response, the information data comprising an address of a network device and an identifier of the subnet to which the client device is associated; encapsulate the processed network configuration parameter response with information data extracted from the processed network configuration parameter response, wherein the processing unit being operative to encapsulate the processed network configuration parameter response comprises the processing unit being operative to, extract the information data comprising a Source-Switch-IP address and a Virtual Network Identifier (VNI) from a Dynamic Host Configuration Protocol (DHCP) option 82 field of the processed network configuration parameter response, and create a Virtual Extensible Local Area Network (VXLAN) header for the encapsulated network configuration parameter response using the Source-Switch-IP address and the VNI extracted from the DHCP option 82 field of the processed network configuration parameter response; and forward, to the network device, the encapsulated network configuration parameter response encapsulated with the created VXLAN header. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein receiving the processed network configuration parameter response comprises receiving the processed network configuration parameter response from a Dynamic Host Configuration Protocol (DHCP) server, the network configuration parameter response comprising a Dynamic Host Configuration Protocol (DHCP) request. ### Claim 18 (depends on 16) The apparatus of claim 16, wherein the information field comprises a Dynamic Host Configuration Protocol (DHCP) option 82 field. ### Claim 19 (depends on 16) The apparatus of claim 16, wherein the information field comprises a Dynamic Host Configuration Protocol (DHCP) option 82 field wherein the identifier of the subnet to which the client device is associated is contained in one of following sub-fields of the DHCP option 82 field: a circuit ID field and a remote ID field. ### Claim 20 (depends on 16) The apparatus of claim 16, wherein the information field comprises a Dynamic Host Configuration Protocol (DHCP) option 82 field wherein the address of the network device is contained in one of following sub-fields of the DHCP option 82 field: a circuit ID field and a remote ID field.