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.