NAT Translates IP Addresses Not MAC | Generated by AI
Question: Is Network Address Translation used to translate IP addresses to MAC addresses, and vice versa?
Answer:
No, that’s not correct.
Network Address Translation (NAT) is a technique used in networking to modify IP addresses (and often ports) in packet headers as they pass through a router or firewall. Its primary purposes are:
- Allowing multiple devices on a private network (using private IP addresses) to share a single public IP address for internet access.
- Conserving public IPv4 addresses.
- Providing a layer of security by hiding internal IP addresses.
NAT operates at the network layer (Layer 3) of the OSI model and only deals with IP addresses (and ports in cases like Port Address Translation or PAT/NAT overload). It does not involve MAC addresses at all.
The process you’re describing—translating between IP addresses and MAC addresses—is handled by the Address Resolution Protocol (ARP), which operates at the data link layer (Layer 2). ARP resolves IPv4 addresses to MAC addresses within a local network segment, and Reverse ARP (RARP) or similar mechanisms can do the opposite (though RARP is largely obsolete).
In summary:
- NAT: IP ↔ IP (and ports)
- ARP: IP → MAC (on local networks)
These are distinct protocols for different layers and purposes.
References:
- Network address translation - Wikipedia
- What Is Network Address Translation (NAT)? - Cisco
- Does NAT change the source MAC address? - Server Fault
- Does NAT Map to the MAC Address, or to the Local IP? - Super User