Cisco NAT fundation

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 no T supported with a Static NAT configuration. Not all platforms and Cisco IOS versions since Cisco IOS Release 12.3 (+) T support the NAT Virtual Interface feature. Therefore, the IP nat enable command might not being accepted on your device, even though is running Cisco IOS Release 12.3 (+) T or later.

Cisco NAT fundation