What technology remaps one IP address space into another?

Network Address Translation (NAT) is the technology that remaps one IP address space into another. It achieves this by translating private (non-routable) IP addresses used within a local network to a public IP address that can be used on the internet. This is particularly useful in conserving the limited number of available public IP addresses and enhances security by hiding the internal IP addresses from external entities.

When a device on a private network wants to communicate with an external network, NAT takes the private IP address and converts it to the public IP address assigned to the NAT device. As responses come back from the external network, NAT translates the public IP address back to the respective private IP address, ensuring that data is directed to the correct internal device.

In contrast, subnetting involves dividing a larger IP network into smaller, more manageable sub-networks but does not actively translate or map addresses to different spaces. IP routing directs packets of data between different networks but is not focused on the remapping of IP address spaces. DHCP is responsible for assigning IP addresses dynamically to devices on a network, rather than translating or remapping them. Each of these other technologies serves a different purpose and does not perform the key function of address space remapping that NAT does.