# US 12,192,165 B2 · Message forwarding and domain name address querying > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,192,165 B2 - Document ID: US12192165B2 - Status: Granted - Kind: B2 - Application number: 17/755,187 - Filed: 2020-10-23 - Published: 2024-06-27 - Granted: 2025-01-07 - Earliest claimed: 2019-10-25 - Assignees: New H3C Security Technologies Co., Ltd. - Applicants: New H3C Security Technologies Co., Ltd. - Inventors: Mingyu Li; Tian Xia - Web page: https://patentgrep.com/patent/US12192165B2 ## CPC - H04L 61/4511: using domain name system [DNS] - H04L 61/25: of the same type - H04L 61/251: between different IP versions - H04L 61/4552: Lookup mechanisms between a plurality of directories; Synchronisation of directories, e.g. metadirectories - H04L 2101/659: Internet protocol version 6 [IPv6] addresses - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract The present disclosure provides a message forwarding method and apparatus, a domain name address query method and apparatus, a network address translation device, and a computer-readable medium. The message forwarding method includes: receiving a first address query request for a target domain name sent by a client; if not finding the network address corresponding to the target domain name locally, sending a second address query request for the target domain name to a domain name system; receiving a second response message returned by the domain name system for the second address query request, which includes a first network address and address translation information; sending a first response message to the client; and after receiving a service message whose destination address is the first network address sent by the client, according to the address translation information, translating the destination address of the service message to the second network address, and sending the service message with the translated destination address to the target server. The method can realize the automatic operation and maintenance of the network address translation equipment and ensure the timely and accurate cross-protocol forwarding of network messages. ## Claims ### Claim 1 A message forwarding method, which is applied to a network address translation device, comprising: receiving a first address query request for a target domain name sent by a client, wherein the client uses a first internet protocol, and a target server corresponding to the target domain name uses a second internet protocol; if a network address corresponding to the target domain name is not found locally, sending a second address query request for the target domain name to a domain name system; receiving a second response message returned by the domain name system for the second address query request, wherein the second response message records a first network address and address translation information between the first network address and a second network address; the second network address includes a network address that supports the second internet protocol and corresponds to the target domain name; and the first network address includes a network address, which supports the first internet protocol, translated by the domain name system from the second network address; sending a first response message for the first address query request to the client, wherein the first response message includes the first network address; and receiving a service message sent by the client, wherein a destination address of the service message is the first network address; translating the destination address of the service message into the second network address according to the address translation information, and sending the service message with the translated destination address to the target server. ### Claim 2 (depends on 1) The message forwarding method according to claim 1, wherein the second response message includes an additional record for recording the address translation information between the first network address and the second network address; and wherein after receiving a second response message returned by the domain name system for the second address query request, the message forwarding method further comprises: searching for an additional record of a predefined type from content area of the second response message; and reading the address translation information between the first network address and the second network address from the additional record of the predefined type. ### Claim 3 (depends on 2) The message forwarding method according to claim 2, wherein, before searching for an additional record of a predefined type from content area of the second response message, the message forwarding method further comprises: if an additional record identifier in header information of the second response message is a first identifier, triggering the searching for an additional record of a predefined type from content area of the second response message. ### Claim 4 (depends on 1) The message forwarding method according to claim 1, wherein, after receiving a second response message returned by the domain name system for the second address query request, the message forwarding method further comprises: determining a second network address corresponding to the first network address according to the first network address and the address translation information recorded in the second response message; and generating a domain name system cache entry according to the first network address, the address translation information and the second network address, and storing the domain name system cache entry locally. ### Claim 5 (depends on 1) The message forwarding method according to claim 1, further comprising: if a first network address corresponding to the target domain name is found locally, triggering the sending a first response message for the first address query request to the client. ### Claim 6 (depends on 1) The message forwarding method according to claim 1, wherein the address translation information includes prefix information for the translation from the first network address to the second network address; or the address translation information includes correspondence information between the first network address and the second network address. ### Claim 7 (depends on 6) The message forwarding method according to claim 6, wherein translating the destination address of the service message to the second network address comprises: translating the destination address of the service message from the first network address to the second network address by adding/deleting the prefix information to/from the first network address; or replacing the destination address of the service message from the first network address with the second network address according to the correspondence information. ### Claim 8 (depends on 6) The message forwarding method according to claim 6, wherein the address translation information includes prefix information for the translation from the first network address to the second network address; and wherein after receiving a second response message returned by the domain name system for the second address query request, the message forwarding method further comprises: generating an address translation rule according to the prefix information, and storing the address translation rule locally, wherein a matching item of the address translation rule includes the prefix information; and wherein translating the destination address of the service message to the second network address comprises: searching for a matched address translation rule locally according to the prefix information of the first network address; and if a matched address translation rule is found, translating the destination address of the service message from the first network address to the second network address according to the matched address translation rule. ### Claim 9 (depends on 1) A network address translation device, comprising: a processor; a transceiver; and a machine-readable storage medium to store machine-executable instructions that are executable by the processor; wherein the machine-executable instructions cause the processor to perform the message forwarding method of claim 1 by means of the transceiver. ### Claim 10 (depends on 1) A non-transitory computer-readable medium with computer-readable instructions stored thereon, wherein the computer-readable instructions are executable by a processor to implement the message forwarding method according to claim 1. ### Claim 11 A domain name address query method, which is applied to a domain name system, comprising: receiving a second address query request sent by a network address translation device for a target domain name, wherein a source address of the second address query request supports a first internet protocol; in response to the second address query request, querying a second network address corresponding to the target domain name, wherein the second network address supports a second internet protocol; translating the second network address to the first network address that supports the first internet protocol; and sending a second response message for the second address query request to the network address translation device, wherein the second response message includes the first network address and address translation information between the first network address and the second network address, so that the network address translation device sends the first network address to a client, and performs a destination address translation on a service message sent by the client according to the address translation information, wherein a destination address of the service message is the first network address. ### Claim 12 (depends on 11) The domain name address query method according to claim 11, wherein the second response message includes an additional record for recording the address translation information between the first network address and the second network address. ### Claim 13 (depends on 11) The domain name address query method according to claim 11, wherein the address translation information includes prefix information for the translation from the first network address to the second network address; or the address translation information includes correspondence information between the first network address and the second network address. ### Claim 14 (depends on 11) The domain name address query method according to claim 11, wherein the address translation information includes correspondence information between the first network address and the second network address; and wherein translating the second network address to the first network address that supports the first internet protocol comprises: selecting a network address that supports the first internet protocol from a preset address pool as the first network address, to which the second network address is to be translated. ### Claim 15 (depends on 11) A non-transitory computer-readable medium with computer-readable instructions stored thereon, wherein the computer-readable instructions are executable by a processor to implement the domain name address query method according to claim 11. ### Claim 16 A domain name system, comprising: a processor; a transceiver; a machine-readable storage medium to store machine-executable instructions that are executable by the processor; wherein the machine-executable instructions cause the processor to perform the following operations: receiving, by the transceiver, a second address query request sent by a network address translation device for a target domain name, wherein a source address of the second address query request supports a first internet protocol; in response to the second address query request, querying a second network address corresponding to the target domain name, wherein the second network address supports a second internet protocol; translating the second network address to the first network address that supports the first internet protocol; and sending, by the transceiver, a second response message for the second address query request to the network address translation device, wherein the second response message includes the first network address, address translation information between the first network address and the second network address, so that the network address translation device sends the first network address to a client, and performs a destination address translation on a service message sent by the client according to the address translation information, wherein a destination address of the service message is the first network address.