This recipe will describe how to create a 1:1 NAT entry. 

1:1 NAT allows us to map a single external IP address to a single internal IP address, or we can map an external network to an internal network. We might have a scenario in which we acquired public IP addresses for different resources—for example, a web server. If the web server is a node on one of our private networks, then we must map the public address to the web server’s private address.