# US 10,374,950 B2 · Routing traffic between networks governed by different versions of the internet protocol > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,950 B2 - Document ID: US10374950B2 - Status: Granted - Kind: B2 - Application number: 15/053,011 - Filed: 2016-02-25 - Published: 2017-08-31 - Granted: 2019-08-06 - Earliest claimed: 2016-02-25 - Assignees: Red Hat, Inc. - Applicants: Red Hat, Inc. - Inventors: Phil Sutter - Web page: https://patentgrep.com/patent/US10374950B2 ## CPC - H04L 45/741: Routing in networks with a plurality of addressing schemes, e.g. with both IPv4 and IPv6 - H04L 61/251: between different IP versions - H04L 61/4511: using domain name system [DNS] - 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 Systems and methods for routing traffic between networks governed by different Internet Protocol (IP) versions. An example method may comprise: receiving a network packet having an original source address defined in a first address space and an original destination address defined in the first address space, wherein the first address space is associated with a first Open Systems Interconnection (OSI) network layer protocol; identifying, using a network layer address mapping transformation, a new destination address associated with the original destination address, wherein the new destination address is defined in a second address space associated with a second OSI network layer protocol; substituting the original destination address of the network packet with the new destination address; selecting, from a pool of available network layer addresses defined in the second address space, a new source address; substituting the original source address of the network packet with the new source address; and causing the network packet to be transmitted to a destination host identified by the new destination address. ## Claims ### Claim 1 A method, comprising: receiving, by a processor executing a kernel space network layer address translation module, a network packet having an original source address defined in a first address space and an original destination address defined in the first address space, wherein the first address space is associated with a first Open Systems Interconnection (OSI) network layer protocol; identifying, using a network layer address mapping transformation, a substitute destination address associated with the original destination address, wherein the substitute destination address is defined in a second address space associated with a second OSI network layer protocol, and wherein the substitute destination address comprises a concatenation of a pre-defined prefix, the original destination address, and a pre-defined suffix; substituting the original destination address of the network packet with the substitute destination address; selecting, from a pool of available network layer addresses defined in the second address space, a substitute source address; associating, by a record of a memory data structure, the original source address and the substitute source address; substituting the original source address of the network packet with the substitute source address; causing the network packet to be transmitted to a destination host identified by the substitute destination address; receiving a domain name system (DNS) request specifying a DNS name associated with the destination host; transmitting a DNS response specifying the substitute destination address; and responsive to detecting a Transmission Control Protocol (TCP) event associated with the substitute source address, purging the record from the memory data structure. ### Claim 2 (depends on 1) The method of claim 1, wherein the first OSI network layer protocol is provided by Internet Protocol version 4 (IPv4). ### Claim 3 (depends on 1) The method of claim 1, wherein the second OSI network layer protocol is provided by Internet Protocol version 6 (IPv6). ### Claim 4 (depends on 1) The method of claim 1, further comprising: receiving, via a graphical user interface (GUI) of a user space module, a parameter of the network address mapping transformation. ### Claim 5 (depends on 1) The method of claim 1, further comprising: receiving, via an application programming interface (API) of a user space module, a parameter of the network address mapping transformation. ### Claim 6 (depends on 1) The method of claim 1, further comprising: receiving a response packet having a source address matching the substitute destination address and further having a destination address matching the substitute source address; substituting, in the response packet, the source address with the original destination address; substituting, in the response packet, the destination address with the original source address; and causing the network packet to be transmitted to a source host identified by the original source address. ### Claim 7 A system, comprising: a memory; and a processor, coupled to the memory, the processor to: receive, by a kernel space network layer address translation module, a network packet having an original source address defined in a first address space and an original destination address defined in the first address space, wherein the first address space is associated with a first Open Systems Interconnection (OSI) network layer protocol; identify, using a network layer address mapping transformation, a substitute destination address associated with the original destination address, wherein the substitute destination address is defined in a second address space associated with a second OSI network layer protocol, and wherein the substitute destination address comprises a concatenation of a pre-defined prefix, the original destination address, and a pre-defined suffix; substitute the original destination address of the network packet with the substitute destination address; select, from a pool of available network layer addresses defined in the second address space, a substitute source address; associate, by a record of a memory data structure, the original source address and the substitute source address; substitute the original source address of the network packet with the substitute source address; cause the network packet to be transmitted to a destination host identified by the substitute destination address; receive a domain name system (DNS) request specifying a DNS name associated with the destination host; transmit a DNS response specifying the substitute destination address; and responsive to detecting a Transmission Control Protocol (TCP) event associated with the substitute source address, purge the record from the memory data structure. ### Claim 8 (depends on 7) The system of claim 7, wherein the first OSI network layer protocol is provided by Internet Protocol version 4 (IPv4). ### Claim 9 (depends on 7) The system of claim 7, wherein the second OSI network layer protocol is provided by Internet Protocol version 6 (IPv6). ### Claim 10 (depends on 7) The system of claim 7, wherein the processor is further to: receive, via a graphical user interface (GUI) of a user space module, a parameter of the network address mapping transformation. ### Claim 11 (depends on 7) The system of claim 7, wherein the processor is further to: receive, via an application programming interface (API) of a user space module, a parameter of the network address mapping transformation. ### Claim 12 (depends on 7) The system of claim 7, wherein the processor is further to: receive a response packet having a source address matching the substitute destination address and further having a destination address matching the substitute source address; substitute, in the response packet, the source address with the original destination address; substitute, in the response packet, the destination address with the original source address; and cause the network packet to be transmitted to a source host identified by the original source address. ### Claim 13 A non-transitory computer-readable storage medium having thereon executable instructions that, when executed by a processor, cause the processor to: receive, by a kernel space network layer address translation module, a network packet having an original source address defined in a first address space and an original destination address defined in the first address space, wherein the first address space is associated with a first Open Systems Interconnection (OSI) network layer protocol; identify, using a network layer address mapping transformation, a substitute destination address associated with the original destination address, wherein the substitute destination address is defined in a second address space associated with a second OSI network layer protocol, and wherein the substitute destination address comprises a concatenation of a pre-defined prefix, the original destination address, and a pre-defined suffix; substitute the original destination address of the network packet with the substitute destination address; substitute the original source address of the network packet with a substitute source address; associate, by a record of a memory data structure, the original source address and the substitute source address; cause the network packet to be transmitted to a destination host identified by the substitute destination address; receive a domain name system (DNS) request specifying a DNS name associated with the destination host; transmit a DNS response specifying the substitute destination address; and responsive to detecting a Transmission Control Protocol (TCP) event associated with the substitute source address, purge the record from the memory data structure. ### Claim 14 (depends on 13) The non-transitory computer-readable storage medium of claim 13, wherein the first OSI network layer protocol is provided by Internet Protocol version 6 (IPv6). ### Claim 15 (depends on 14) The non-transitory computer-readable storage medium of claim 14, wherein the second OSI network layer protocol is provided by Internet Protocol version 4 (IPv4). ### Claim 16 (depends on 14) The non-transitory computer-readable storage medium of claim 14, further comprising executable instructions to cause the processor to: receive a response packet having a source address matching the substitute destination address and further having a destination address matching the substitute source address; substitute, in the response packet, the source address with the original destination address; substitute, in the response packet, the destination address with the original source address; and cause the network packet to be transmitted to a source host identified by the original source address.