In policy-based 1-to-1 NAT, your XTM device uses the private and public IP ranges that you set when you configured global 1-to-1 NAT, but the rules are applied to an individual policy. 1-to-1 NAT is enabled in the default configuration of each policy. If traffic matches both 1-to-1 NAT and dynamic NAT policies, 1-to-1 NAT takes precedence.
Because policy-based 1-to-1 NAT is enabled by default, you do not need to do anything else to enable it. If you have previously disabled policy-based 1-to-1 NAT, select the check box in
About 1-to-1 NAT
Configure Firewall 1-to-1 NAT