Configure Static NAT on Cisco IOS

Static NAT on Cisco IOS Routers. Static NAT is a one to one NAT between IP addresses, one Private IP to one Public IP.
 
NAT Inside Interface
Enable one interface on the router with an IP Address, mark it the NAT INSIDE interface. This is the interface that connects to your internal private network

Router(config)# int fastethernet0/1
Router(config-if)# ip address 192.168.1.1 255.255.255.0
Router(config-if)# ip nat inside

Enable NAT Outside Interface
Enable one interface on the router with an IP Address, mark it as the NAT OUTSIDE interface. This is the interface that connects to your outside public network

Router(config)# int serial0/0/0
Router(config-if)# ip address 100.100.100.100 255.255.255.0
Router(config-if)# ip nat outside

Instruct Router to NAT the Source IP Address to that of a NAT'd IP.

Router(config)# ip nat inside source static 192.168.1.2 100.100.100.101
Router(config)# ip nat inside source static 192.168.1.3 100.100.100.102
Router(config)# ip nat inside source static 192.168.1.4 100.100.100.103

Where 192.168.1.x IP's are NAT'd to 100.100.100.x

The syntax is

ip nat inside source static x.x.x.x y.y.y.y

Note: Static NAT's can co-exist with NAT Overloading or Dynamic NATs.

To Check the NAT Status and Statistics

Router# show ip nat statistics

To See the Active Translations

Router# show ip nat translations