Router Configuration: IP NAT

Command:
     ip nat inside source

Mode:
     Router(config) #

Syntax:
     ip nat inside source {list {access-list-number | name} {pool name | interface dialer-name} [overload] | static local-ip global-ip}

    no ip nat inside source {list {access-list-number | name} {pool name | interface dialer-name} [overload] | static local-ip global-ip} 

Command Description:
     To enable NAT of the inside source address, use the ip nat inside source global configuration command. 

Example:

The following portion of a show running-config translates between inside hosts addressed from either the 192.168.1.0 or 192.168.2.0 networks to the globally unique 171.69.233.208/28 network:

ip nat pool net-208 171.69.233.208 171.69.233.223 prefix-length 28
ip nat inside source list 1 pool net-208
!
interface ethernet 0
ip address 171.69.232.182 255.255.255.240
ip nat outside
!
interface ethernet 1
ip address 192.168.1.94 255.255.255.0
ip nat inside
!
access-list 1 permit 192.168.1.0 0.0.0.255
access-list 1 permit 192.168.2.0 0.0.0.255
!
ip classless
ip route 192.168.0.0 255.255.252.0 e1
ip route 0.0.0.0 0.0.0.0 e0

Original link Soft30