A method of remapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device. It involves associating one internal address with exactly one external address. For instance, a server within a private network using the address 192.168.1.10 might be represented externally using the public address 203.0.113.5. This creates a direct, unchanging correspondence between the internal and external IP, effectively masking the internal address but allowing for consistent bidirectional communication.
This technique is beneficial in situations requiring a persistent external presence for internal resources. It simplifies network management by maintaining consistent IP address mappings, which is especially useful for services like email servers or web servers that need to be reliably accessed from the internet. This offers a solution for organizations migrating to new infrastructure or merging networks with overlapping address spaces, enabling seamless integration and uninterrupted service. Its relevance has evolved from basic address conservation to enabling specific security configurations and simplifying complex network architectures.