Topology
1. DNAT (Dynamic)
int fa0/0
ip nat inside
int fa0/1
ip nat outside
ip nat pool ISP-POOL 198.51.100.3 192.51.100.14 netmask 255.255.255.240
ip nat inside source list 1 pool ISP-POOL
access-list 1 permit 10.1.1.0 0.0.0.255
show ip nat translations
2 SNAT (Static)
ip nat inside source static 10.1.1.1 198.51.100.3
ip nat inside source static 10.1.1.2 198.51.100.4
3 PAT (Port Address Translation)
int f0/0
ip nat inside
int f0/1
ip nat outside
ip nat inside source list 1 interface fastethernet0/1 overload
access-list 1 permit 10.1.1.0 0.0.0.255
show ip nat translations
4 NVI (NAT Virtual Interface)
int f0/0
ip nat enable
int f0/1
ip nat enable
NOTE: The NAT Vitrual Interface feature can be used with a Dynamic NAT configuration or a PAT configuration , but it is not supported with a Static NAT configuration. Not all platforms and Cisco IOS versions since Cisco IOS Release 12.3(14)T support the NAT Virtual Interface feature . Therefore , the ip nat enable command might not be accepted on your device , even though you are running Cisco IOS Release 12.3(14)T or later .