Understanding NAT rules in network security Think of NAT rules as a security checkpoint's rulebook. Just like airport security follows specific protocols to screen passengers, NAT rules provide firewalls with clear instructions on how to handle network traffic between internal and external networks.
Sources: NIST SP 800-86 under Network Address Translation A function by which internet protocol addresses within a packet are replaced with different IP addresses. This function is most commonly performed by either routers or firewalls. It enables private IP networks that use unregistered IP addresses to connect to the internet.
By masking internal IP addresses, it reduces the attack surface available to external threats. Attackers attempting to infiltrate a network from the outside would typically encounter the public IP address of the NAT-enabled router or firewall, rather than individual devices within the internal network.
The NAT gateway (NAT router) performs IP address rewriting on the way while packets travel from/to LAN. In RouterOS NAT is supported for IPv4. RouterOS does not support NAT64.
